32653	----	UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 15, No. 9, pp. 469-491, 4 figs. March 2, 1964 A Review of the Frogs Of the Hyla bistincta Group BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1964 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 15, No. 9, 469-491, 4 figs. Published March 2, 1964 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY THE STATE PRINTER TOPEKA, KANSAS 1964 29-8590 A Review of the Frogs Of the Hyla bistincta Group BY WILLIAM E. DUELLMAN CONTENTS PAGE INTRODUCTION 471 Acknowledgments 471 THE HYLA BISTINCTA GROUP 472 Analysis of Characters 473 Key to the Species of the Hyla Bistincta Group 474 ACCOUNTS OF THE SPECIES 475 _Hyla bistincta_ Cope 475 _Hyla charadricola_ new species 478 _Hyla robertsorum_ Taylor 481 _Hyla pachyderma_ Taylor 485 _Hyla crassa_ (Brocchi) 486 RELATIONSHIPS 489 LITERATURE CITED 491 INTRODUCTION In the mountainous regions of Middle America there are several groups of hylid frogs that inhabit mountain streams. Some of these groups, such as _Plectrohyla_ and _Ptychohyla_, have been elevated to generic rank, whereas others are retained in the large and complex genus _Hyla_. In the mountains of México five species of hylids that seem to compose a phyletic unit are herein referred to as the _Hyla bistincta_ group. Since 1955 I have been accumulating specimens of, and data on, this group with the result that all specimens known to me, including the types of all named taxa, have been studied. Detailed observations have been made on the ecology and life histories of three of the species; the other two species are known to me only from preserved specimens. Acknowledgments For permission to examine specimens in their care I am indebted to Charles M. Bogert, American Museum of Natural History (AMNH); Doris M. Cochran, United States National Museum (USNM); Jean Guibé, Museum National d'Histoire Naturelle, Paris (MNHN); Robert F. Inger, Chicago Natural History Museum (CNHM); Hobart M. Smith, University of Illinois Museum of Natural History (UIMNH); Charles F. Walker, University of Michigan Museum of Zoology (UMMZ). (Abbreviations of institutions given above in parentheses are used throughout; the Museum of Natural History, University of Kansas is abbreviated KU.) For their willing assistance in the field I am grateful to Ann S. Duellman, Dale L. Hoyt, and John Wellman. Permits for collecting in México were generously issued by the late Ing. Luis Macías Arellano, Departamento de la Fauna Silvestre, Dirección General de Caza. The drawings in figures 1 and 3 were executed by Gail Selfridge. This research has been supported by the National Science Foundation (NSF G-9827). THE HYLA BISTINCTA GROUP The five species comprising the _Hyla bistincta_ group are moderate-sized hylids having rather blunt heads and robust bodies. The fingers are long and have little webbing (Fig. 1). The skin of the dorsum is thick and glandular, but not tuberculate. An anal sheath is present. The skull is rather broad, flat, and solidly roofed. The ethmoid is broad, curved downward laterally, and solidly sutured to the frontoparietal. The nasals are broad, sutured for their entire width with the ethmoid, and broadly in contact medially. The premaxillaries are in contact medially; each has a long, flat nasal process. The quadratojugal is absent, and the maxillary tapers to a point posteriorly. There is no squamosal-maxillary connection. The maxillary and premaxillary teeth are rather long, bifid, and moderately spatulate. Some teeth on the premaxillary and anterior part of the maxillary are hooked. The vomerine teeth are spatulate and bifid. A broad, flat, ossified prepollex is present but does not project as a spine. The known tadpoles have ventral mouths, 2/3 tooth-rows, two or more rows of labial papillae, and long tails with low fins. [Illustration: FIG. 1. Palmar view of right hand of: _a._--_Hyla robertsorum_ (KU 57661), _b._--_Hyla charadricola_ (KU 58414). × 3.] As thus defined the _Hyla bistincta_ group can be distinguished from all other groups of Middle American frogs by the combination of absence of the quadratojugal, non-projecting prepollex, long fingers with little webbing, and stream-inhabiting tadpoles having 2/3 tooth rows and two or more rows of labial papillae. Possibly _Hyla arborescandens_ and _Hyla hazelae_ belong in this group. Because these species are somewhat different from the included species and because their tadpoles are as yet unknown, I have refrained from including these two species in the _Hyla bistincta_ group. Taylor (1948:261) assigned _Hyla proboscidea_ (= _H. dalquesti_) and (1949:272) _Hyla cyclomaculata_ to this group, but because these two species have a quadratojugal and notably different tadpoles, they are excluded from the group. Frogs of the genus _Plectrohyla_ closely resemble species in the _Hyla bistincta_ group but differ principally in having a projecting prepollex. In the highlands of Costa Rica a group of species, of which _Hyla moesta_ is best known, resembles species in the _Hyla bistincta_ group. At present insufficient information is available on the Costa Rican species to determine their affinities. Analysis of Characters The characters used in the systematic study of the frogs in this group are those usually employed in anuran systematics. Of the various measurements and proportions, the snout-vent length and the relative size of the tympanum to the eye apparently are of more taxonomic importance than the others (Table 1). In all of the species the tympanum is at least partially covered by a heavy, dermal supratympanic fold, and in some specimens of _H. pachyderma_ the tympanum is completely obscured. In two species (_H. bistincta_ and _H. charadricola_) the snout is square, whereas in the other species it is round. The fingers are long and slender in _H. crassa_, _pachyderma_, and _robertsorum_ and somewhat shorter with more webbing in _H. bistincta_ and _charadricola_. Breeding males of _Hyla pachyderma_ have moderately large nuptial spines; the other species have small spines, except _H. charadricola_ in which spines apparently are absent. A well-defined thoracic fold is present in _H. pachyderma_, and a weak fold is present in _H. robertsorum_; the other species lack folds. In all species there is an anal sheath; this sheath is longest in _H. bistincta_, in which the anal opening is directed ventrally at the level of the lower edge of the thighs. TABLE 1.--COMPARISON OF CERTAIN MEASUREMENTS AND PROPORTIONS IN THE SPECIES OF THE HYLA BISTINCTA GROUP. (DATA FROM ADULT MALES; MEANS ARE GIVEN IN PARENTHESES BELOW THE RANGES.) A: Snout-vent length B: Tibia length / Snout-vent length C: Head width / Snout-vent length D: Tympanum / Eye ==================================================================== SPECIES | N | [A] | [B] | [C] | [D] ---------------+----+-----------+-----------+-----------+----------- _H. bistincta_ | 38 | 43.0-53.8 | 0.47-0.52 | 0.32-0.37 | 0.35-0.48 | | (46.3) | (0.49) | (0.34) | (0.42) | | | | | _H. | 10 | 35.3-44.4 | 0.50-0.54 | 0.31-0.33 | 0.30-0.37 charadricola_ | | (40.4) | (0.52) | (0.32) | (0.34) | | | | | _H. | 26 | 39.9-47.9 | 0.48-0.51 | 0.30-0.36 | 0.36-0.47 robertsorum_ | | (43.1) | (0.49) | (0.32) | (0.41) | | | | | _H. pachyderma_| 1 | 39.9 | 0.53 | 0.32 | ... | | | | | _H. crassa_ | 1 | 53.7 | 0.50 | 0.33 | 0.28 ---------------+----+-----------+-----------+-----------+----------- Frogs in this group are rather drab in appearance. The dorsal color varies from dull green to various shades of brown. The most distinct aspect of the coloration is the different color patterns on the flanks and posterior surfaces of the thighs. The flanks in all species are marked with spots or reticulations. _Hyla bistincta_ differs from other members of the group in having vocal slits and a distensible vocal sac. Only this species has been reported to call (Shannon, 1951:473). Insofar as is known, the other species are mute. Examination of skeletal preparations of _H. bistincta_, _charadricola_, and _robertsorum_ and X-rays of the other species shows no notable specific differences in the osteology. Since the tadpoles of only _H. bistincta_ (Duellman, 1961:47) and _H. robertsorum_ (Rabb and Mosimann, 1955) are known, larval characters are of limited use in intra-group systematics. Key to the Species of the _Hyla bistincta_ Group 1. Snout, in dorsal profile, short and bluntly rounded; canthus rounded, sometimes indistinct, vocal slits absent 2 Snout, in dorsal profile, longer, squared; canthus distinct, vocal slits present or absent 4 2. Feet webbed to base of discs; dorsum dull olive green; flanks having cream-colored spots _H. crassa_, p. 486 Feet not webbed to base of discs; dorsum brown 3 3. Tarsal fold strong; thoracic fold heavy; webbing on feet extending to middle of penultimate phalanx of fourth toe; distinct white stripe above anus; cluster of largo spines on thumb in breeding males, _H. pachyderma_, p. 485 Tarsal fold weak and short; thoracic fold absent or barely indicated; webbing of feet extending to base of penultimate phalanx of fourth toe; no distinct white stripe above anus; nuptial tuberosities in breeding males consisting of small spines _H. robertsorum_, p. 481 4. Tarsal fold strong; anal flap elongate; anus opening at lower edge of femur; dorsum tan or brown; flanks mottled with cream and brown; venter immaculate creamy white; no anal stripe; vocal slits present, _H. bistincta_, p. 475 Tarsal fold faint and short; anal flap not elongate; anus opening at middle of femur; dorsum olive-green with black reticulations; flanks greenish gray with brown or black spots; a row of white flecks above and below anus, vocal slits absent _H. charadricola_, p. 478 ACCOUNTS OF THE SPECIES In the following accounts complete synonymies are given for each species. In each account one specimen is described in detail; after this description the variation is discussed. In the list of specimens examined, localities are arranged alphabetically within the states, which also are given in alphabetical order. Localities given in italics are not shown on the accompanying maps (Figs. 2 and 4) due to crowding of symbols. #Hyla bistincta# Cope _Hyla bistincta_ Cope, Proc. Amer. Philos. Soc, 17:87, August, 1877 [Holotype.--USNM 32261 from "most probably Veracruz," México; Francis Sumichrast collector]. Brocchi, Étude des batraciens de l'Amérique Centrale, p. 43, 1881. Boulenger, Catalogue Batrachia Salientia, 2nd Ed., p. 401, February 1, 1882. Sumichrast, La Naturaleza, 6:81, 1882. Cope, Bull. U. S. Natl. Mus., 32:14, 1887; Bull. U. S. Natl. Mus., 34:351, 1889. Günther, Biologia Centrali-Americana, Reptilia and Batrachia, pp. 265-6, June, 1901. Díaz de León, Indice de los batracios que se encuentran en la República Mexicana, p. 17, June, 1904. Nieden, Das Tierreich, Amphibia, Anura I, p. 247, June, 1923. Kellogg, Bull. U. S. Natl. Mus., 160:163-164, March 31, 1932. Taylor, Proc. Biol. Soc. Washington, 50:50-53, April 21, 1937; Univ. Kansas Sci. Bull., 26:389, November 27, 1940. Taylor and Smith, Proc. U. S. Natl. Mus., 194:87, June 7, 1948. Taylor, Univ. Kansas Publ. Mus. Nat. Hist., 1:261, August 16, 1948; Copeia, no. 4:272-273, December 15, 1949. Smith and Taylor, Univ. Kansas Sci. Bull., 33:346, March 20, 1950 [Type locality restricted to Acultzingo, Veracruz, México]. Rabb and Mosimann, Occas. Papers Mus. Zool. Univ. Michigan, 563:6-9, March 29, 1955. Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 15:47-49, December 20, 1961. _Hyla bistincta labeculata_ Shannon, Proc. U. S. Natl. Mus., 101:470-473, figs. 92a, 93d, May 17, 1951 [Holotype.--USNM 123689 from San Lucas Camotlán, Oaxaca, México; Walter S. Miller collector]. Smith and Williams, Herpetologica, 19:23, April 11, 1963. _Hyla bistincta bistincta_, Shannon, Proc. U. S. Natl. Mus., 101:472, May 17, 1951. Shannon and Werler, Herpetologica, 11:85, July 15, 1955. Smith and Williams, Herpetologica, 19:23, April 11, 1963. _Diagnosis._--Maximum snout-vent length in males 54 mm.; snout in dorsal profile truncate; tarsal fold strong; inner metatarsal tubercle large, high, and elongate; outer metatarsal tubercle absent; webbing on foot extending to middle of antepenultimate phalanx of fourth toe; nuptial spines on thumb small; thoracic fold absent; anal opening at level of lower edge of femur; dorsum brown or tan; belly cream-color; flanks creamy yellow with brown reticulations or spots; anal stripe absent; vocal slits present. _Description._--The following description is based on KU 68078 from Uruapan, Michoacán, México. Adult male having a snout-vent length of 43.2 mm.; tibia length, 22.1 mm., 51.1 per cent of snout-vent length; foot length (measured from proximal edge of inner metatarsal tubercle to tip of longest toe), 20.8 mm.; greatest width of head, 15.4 mm., 35.6 per cent of snout-vent length; head length, 13.9 mm., 32.1 per cent of snout-vent length; diameter of eye, 5.1 mm.; diameter of tympanum, 2.4 mm., 47.1 per cent of diameter of eye. Snout in lateral profile bluntly rounded, in dorsal profile truncate; canthus pronounced, rounded, not angular; loreal region slightly concave; lips thick, round, not flaring; nostrils slightly protuberant; internarial distance, 3.4 mm.; interorbital distance, 4.5 mm., somewhat broader than width of eyelid, 3.5 mm. A heavy dermal fold from posterior corner of eye above tympanum and curved downward to insertion of forearm; tympanum round, its diameter slightly more than its distance from eye. Forearm not robust; row of small pustules on ventral surface of forearm; fold on wrist; prepollex moderately enlarged, covered with small, horny, nuptial spines continuous on edge of digit; row of spines on inner surface of second finger; subarticular tubercles large, round, none bifid; supernumerary tubercles rather large, round; palmar tubercles rather small, flat, elliptical; fingers long, moderately slender; length of fingers from shortest to longest, 1-2-4-3; discs moderately large, that on third finger slightly larger than tympanum; rudimentary web between first and second and between second and third fingers; web between third and fourth fingers extending about one-fourth length of fourth finger. Heels overlap by about one-third length of shank when hind limbs adpressed; tibiotarsal articulation extends to anterior edge of eye; tarsal fold strong, extending to heel; inner metatarsal tubercle large, high, and elongate; outer metatarsal tubercle absent; subarticular tubercles moderately large, round; supernumerary tubercles small, in single rows on proximal segments of digits; toes moderately short; length of toes from shortest to longest, 1-2-3-5-4, third and fifth toes about equal in length; toes about two-thirds webbed; web extending to middle of antepenultimate phalanx of fourth toe, to discs of first, second, and fifth toes, and to base of penultimate phalanx of third toe; discs rather small, about two-thirds size of those on fingers. Anal opening at level of lower edge of thighs; anal sheath elongate, deeply creased medially; transverse dermal fold above anus. Skin of dorsal surfaces of head, body, and limbs faintly areolate; skin of chin, belly, and ventral surfaces of thighs granular, that of ventral surfaces of limbs, except thighs, areolate; thoracic fold absent. Tongue nearly round, slightly longer than wide, shallowly notched behind and barely free posteriorly. Vomerine teeth 4-4, situated on rounded vomerine ridges between rather small ovoid inner nares; vocal slits present, situated along posterior edge of each ramus. Color (in alcohol) pale brown on dorsal surfaces of head, body, and limbs; flanks and anterior surfaces of thighs creamy white with dark brown reticulations; posterior surfaces of thighs tan with creamy white spots; belly cream-color; anal stripe absent. Color (in life) pale tan on dorsal surfaces; flanks and anterior surfaces of thighs pale creamy yellow with purplish brown reticulations; posterior surfaces of thighs tan with yellow spots; ventral surfaces yellow; iris pale copper-color. _Variation._--There is little variation in structure. The total number of vomerine teeth varies from 6 to 14. In some individuals the supratympanic fold covers the upper part of the tympanum, but at least the lower part of the tympanum is always visible. The extent of the webbing between the toes varies from three-fourths to two-thirds complete. Usually the web extends to some point on the antepenultimate phalanx of the fourth toe, but in some specimens the web extends to the base of the penultimate phalanx. In the large series of specimens from Uruapan, Michoacán, the coloration of the flanks and anterior surfaces of the thighs varies from nearly uniform creamy yellow with only fine dark reticulations to bold reticulations enclosing yellow spots. Some specimens from Oaxaca and Veracruz have slightly different markings on the flanks; in these the dark pigment is in the form of irregular spots or dashes, instead of reticulations. There is considerable variation in color in the living frogs. The dorsum varies from greenish tan and pale yellowish tan to reddish brown, and some individuals are dark chocolate brown. _Remarks._--Shannon (1951:470) named _Hyla bistincta labeculata_ on the basis of a single male from San Lucas Camotlán, Oaxaca; he diagnosed the subspecies as differing from _Hyla bistincta bistincta_ by having "the gray reticulation of the sides entirely broken up into elongate black blotches; tarsal fold moderately elevated." The condition of the tarsal fold is characteristic of the species. The dispersion of dark pigment on the flanks is variable. The type of _Hyla bistincta labeculata_ (USNM 123689) is extreme in the development of dark dashes on the flanks, but this condition is approached in several specimes from Oaxaca and Veracruz. For example, in some specimens from Cumbres de Acultzingo, Veracruz, the mottling on the flanks is bold; in others the flanks are reticulated. The specimen from San Vicente, Oaxaca, has black dashes on the flanks (Smith and Williams, 1963:23), whereas a specimen from Cerro San Felipe, Oaxaca, has no pattern on the flanks. In general, specimens from western México have reticulate mottling on the flanks as compared with the marbling on the flanks in specimens from eastern México. On the basis of available data, the recognition of subspecies in _Hyla bistincta_ is unwarranted. The tadpoles of this species described by Duellman (1961:47) are like those of _Hyla robertsorum_ in having 2/3 tooth-rows, peglike serrations on the beaks, and long, rounded tails. At Uruapan tadpoles were found in a rocky stream on April 24, 1956, and metamorphosing young were found there on August 2, 1956. A completely metamorphosed juvenile has a snout-vent length of 24.8 mm. _Hyla bistincta_ is found only along streams, where individuals can be seen clinging to vines and other vegetation closely over-hanging fast-moving parts of the stream. _Distribution._--_Hyla bistincta_ occurs at elevations from 1400 to 2600 meters in the mountains of the Sierra Madre Occidental in western Jalisco southward through the Cordillera Volcánica in Michoacán, México, and Morelos, the Sierra de Coalcomán in Michoacán, and the Sierra Madre del Sur in Guerrero and Oaxaca, and thence northward in the Sierra Madre Oriental to central Veracruz (Fig. 2). Specimens examined.--GUERRERO: Omiltemi, UIMNH 38023-5. JALISCO: 25 km. SE Autlán, UMMZ 102076. MEXICO: 19 km. W Villa Victoria, UIMNH 28162, USNM 114513. MORELOS: Cuernavaca, USNM 121523; _3 km. N Cuernavaca_, UIMNH 28168-70. MICHOACAN: Cerro San Andrés, UMMZ 102075; Dos Aguas, UMMZ 119193; _12.5 km. ENE Dos Aguas_, UMMZ 119194; _Los Conejos_, UMMZ 94238-40; Uruapan, KU 68077-8, 69093 (skeleton), UIMNH 20457, 28167, UMMZ 85452-3, 112838, 112839 (16), 115231 (tadpoles), 115232, 115233 (12), 121515, S-1699 (skeleton), S-1826 (skeleton), USNM 114514-5, 114517-24. OAXACA: Cerro San Felipe, UIMNH 28163; Pluma Hidalgo, AMNH 13447; San Lucas Camotlán, USNM 123689; San Vincente, UIMNH 51346 (Smith and Williams, 1963:23). VERACRUZ: no specific locality, USNM 32261; Cumbres de Acultzingo, CNHM 105482-3, UIMNH 28164-6, 49133-4, USNM 114525. [Illustration: FIG. 2. Map showing locality records for _Hyla bistincta_ and _Hyla charadricola_.] #Hyla charadricola# new species _Holotype._--University of Kansas Museum of Natural History No. 58414 from the Río Totolapa, 14.4 kilometers by road west of Huachinango, Puebla, México, 2280 meters; obtained by John Wellman on June 8, 1960. _Paratypes._--KU 58415-58423, same data as holotype, and UIMNH 50966, obtained at the type locality by William E. Duellman on February 11, 1961. _Diagnosis._--Maximum snout-vent length in males, 45 mm.; snout in dorsal profile truncate; tarsal fold short and weak; inner metatarsal tubercle moderately large, elliptical, and flat; outer metatarsal tubercle minute, round, and indistinct; webbing extending to base of terminal phalanx of fourth toe; nuptial spines on thumb absent; thoracic fold absent; anal opening at level of middle of thigh; dorsum olive-green with black reticulations; venter cream color with brown flecks on chin; flanks pale grayish green with brown spots; anal stripe absent; row of white flecks above and a row below anus; vocal slits absent. _Description of Holotype._--Adult male having a snout-vent lenth of 44.4 mm.; tibia length, 22.2 mm., 50 per cent of snout-vent length; foot length (measured from proximal edge of inner metatarsal tubercle to tip of longest toe), 20.4 mm.; greatest width of head, 14.0 mm., 31.5 per cent of snout-vent length; head length, 13.6 mm., 30.6 per cent of snout-vent length; diameter of eye, 5.0 mm.; diameter of tympanum, 1.6 mm., 32.0 per cent of diameter of eye. Snout in lateral profile bluntly rounded, in dorsal profile truncate (Fig. 3); canthus pronounced, rounded, not angular; loreal region slightly concave; lips thick, rounded, not flaring; nostrils slightly protuberant; internarial distance, 3.7 mm.; interorbital distance, 4.1 mm., somewhat broader than width of eyelid, 3.3 mm. A heavy dermal fold from posterior corner of eye above tympanum and then to insertion of forearm; tympanum round, its diameter three-fourths its distance from eye. Forearm rather slender; a short axillary membrane; no fold on wrist; no nuptial excrescence or spines on enlarged prepollex; subarticular tubercles moderately small, round; none bifid; few supernumerary tubercles on proximal segments of digits; large, flat palmar tubercle present; fingers long and slender; length of fingers from shortest to longest, 1-2-4-3; discs moderately large, that on third finger about equal to diameter of tympanum; rudimentary web between first and second fingers; web between third and fourth fingers extending to about one-fifth length of fourth finger (Fig. 1). Heels overlap by about one-third length of tibia when hind limbs adpressed; tibiotarsal articulation extends to middle of eye; tarsal fold weak, extending from moderately large, flat, elliptical inner metatarsal tubercle to middle of tarsus; outer metatarsal tubercle minute, round, indistinct; subarticular tubercles round; single row of small, round supernumerary tubercles on proximal segments of each digit; toes moderately short and slender; length of toes from shortest to longest, 1-2-3-5-4, third and fifth about equal in length; toes about three-fourths webbed; web extending to base of terminal phalanx of fourth toe; discs small, about two-thirds size of those on fingers. Anal opening directed posteroventrally at middle of thighs; two transverse dermal folds above anus; short, thin anal sheath present; many small tubercles lateral and ventral to anal opening. Skin of dorsum, chin, and ventral surfaces of limbs smooth; belly moderately granular; posterior surfaces of thighs heavily granular; no thoracic fold. Tongue nearly round, shallowly notched behind, free posteriorly for about one-fourth its length; vomerine teeth, 3-4, long, situated on posteroventral edges of narrow transverse vomerine ridges between moderately large, round inner nares; no vocal slits. Color (in alcohol) purplish brown on dorsal surfaces of head, body, and limbs; fine darker reticulations on dorsum; flanks pale tan with dark brown spots; posterior surfaces of thighs tan; chin creamy white with brown spots; belly dusty white; undersides of thighs and shanks yellow; webbing grayish brown; undersides of first two fingers dusty white, of third and fourth fingers and of feet brown; anal stripe absent; small white flecks above and below anal opening. Color (in life) dark green on dorsal surfaces of head, body, and limbs; darker green reticulations on back; flanks dusty white with dark olive-gray mottling; dark olive-gray stripe from nostril through eye and then to insertion of forelimb; upper lips pale green; inguinal region, anterior and posterior surfaces of thighs dark yellowish orange; ventral surfaces of tarsi and shanks, and webbing of feet dusty yellow; belly white; iris silvery gold. [Illustration: FIG. 3. Holotype of _Hyla charadricola_ (KU 58414). × 1.5.] _Variation._--Adult males have snout-vent lengths from 35.3 to 44.4 mm., and adult females from 43.4 to 50.9 mm. No notable variation in structure is displayed in the type series. In some individuals the dark reticulation on the dorsum is faint. Juveniles in life had dorsal colorations varying from rich brown with darker reticulations to pale green or gray with dark green reticulations. Some adults when collected were pale green with faint or no dorsal reticulations; later these individuals darkened. In all specimens the anal stripe is absent, and the flanks are heavily spotted. _Comparisons.--Hyla charadricola_ differs from all other members of the _Hyla bistincta_ group in the following combination of characters: truncate snout, green dorsum, and absence of a thoracic fold. From other hylids that occur in the same area, _Hyla charadricola_ differs from _Hyla miotympanum_ and _H. arborescandens_, both of which are green dorsally, by having a truncate snout and longer fingers with less webbing. _Hyla eximia_, though green, has brown dorsal spots, shorter fingers, and a round snout. _Hyla robertsorum_ differs in having a round snout and brown dorsum, and _Hyla taeniopus_ is much larger, has transverse bands on the limbs, and has extensive webbing between fingers. _Remarks._--At the type locality, a shallow rocky stream in pine forest, _Hyla charadricola_ was found beneath rocks at the edge of fast moving sections of the stream and beneath rocks in shallow riffles in the stream. Most of the frogs were in water. At night they were found sitting on rocks in the stream. _Hyla miotympanum_, which is abundant at the type locality, lives in bushes and beneath rocks along the stream but usually is not found in the riffles inhabited by _Hyla charadricola_. At Lago de Tejocotal _Hyla charadricola_ was found beneath rocks near the shore of the lake and by a stream in the pine forest. Individuals were found on low vegetation over-hanging a small stream in pine-oak forest four kilometers southwest of Tianguistengo. Five recently metamorphosed young (KU 58424-9) found at the type locality on June 8, 1960, have snout-vent lengths of 22.4 to 24.0 (average 23.2) mm. The young are colored like the adults, except that in life the dorsum is a brighter green and the flanks are more yellow than tan and have less dark spotting than in adults. _Distribution.--Hyla charadricola_ inhabits streams in pine and pine-oak forests at elevations of 2000 to 2300 meters in northern Puebla and eastern Hidalgo (Fig. 2). Specimens examined.--HIDALGO: Lago de Tejocotal, 11 km. E Acaxochitlán, KU 58438, UMMZ 104032, 118165; 4 km. SW Tianguistengo, KU 53811-2. PUEBLA: _11.7 km. W Huachinango_, UMMZ 121567 (5); Río Totolapa, 14.4 km. W Huachinango, KU 53813-5, 55624, 58414-37, 59813 (skeleton), 59886 (skeleton), MCZ 34964-5, UIMNH 50966, UMMZ 118166 (5), S-2242 (skeleton). #Hyla robertsorum# Taylor _Hyla robertsorum_ Taylor, Univ. Kansas Sci. Bull., 26:393-396, figs. 5-6, November 27, 1940 [Holotype.--CNHM 100124 (formerly EHT-HMS 16264) from El Chico Parque Nacional, Hidalgo, México; Mr. and Mrs. Radclyffe Roberts and Edward H. Taylor collectors]; Univ. Kansas Sci. Bull., 28:310, November 15, 1942. Taylor and Smith, Proc. U. S. Natl. Mus., 95:589, June 30, 1945. Smith and Taylor, Bull. U. S. Natl. Mus., 194:87, June 17, 1948; Univ. Kansas Sci. Bull., 33:333, March 20, 1950. Rabb and Mosimann, Occas. Papers Mus. Zool. Univ. Michigan, 563:1-9, March 29, 1955. Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 15:48, December 20, 1961. _Diagnosis._--Maximum snout-vent length in males, 48 mm.; snout in dorsal profile rounded; tarsal fold short and weak; inner metatarsal tubercle moderate in size and elliptical; outer metatarsal tubercle small, round, and indistinct; webbing extending to base of penultimate phalanx of fourth toe; nuptial spines on thumb small; weak thoracic fold present; anal opening above level of middle of thighs; dorsum dark brown with dark reticulations; venter brown with cream-colored flecks; flanks brown with creamy white spots; anal stripe absent; small white spots in anal region; vocal slits absent. _Description._--The following description is based on KU 57651 from El Chico Parque Nacional, Hidalgo. Adult male having a snout-vent length of 45.1 mm.; tibia length, 22.1 mm., 49.0 per cent of snout-vent length; foot length (measured from proximal edge of inner metatarsal tubercle to tip of longest toe), 21.5 mm.; greatest width of head, 13.7 mm., 30.4 per cent of snout-vent length; head length, 12.6 mm., 27.9 per cent of snout-vent length; diameter of eye, 4.0 mm.; diameter of tympanum, 1.8 mm., 45 per cent of diameter of eye. Snout short, in lateral profile blunt, in dorsal profile round; canthus rounded; loreal region slightly concave; lips thick, round, and not flaring; nostrils slightly protuberant; internarial distance, 3.6 mm.; interorbital distance, 4.0 mm., slightly broader than width of eyelid, 3.5 mm. A moderately heavy dermal fold from posterior corner of eye above tympanum and curving downward towards insertion of forearm; tympanum nearly round, covered by dermal fold above, its diameter slightly less than its distance from eye. Forearm moderately robust; distinct fold on wrist; prepollex much enlarged with patch of small nuptial spines continuous on side of digit; similar line of nuptial spines on inner edge of second finger; subarticular tubercles round, moderate in size, none bifid; supernumerary tubercles small and present only proximally; fingers long and slender; length of fingers from shortest to longest, 1-2-4-3; discs moderately large, that on third finger about size of tympanum; no web between first and second fingers; rudimentary web between other fingers. Legs robust; heels over-lap by about one-fourth length of shank when hind limbs adpressed; tibiotarsal articulation extending to posterior corner of eye; tarsal fold weak, extending to about middle of tarsus; inner metatarsal tubercle moderately large, flat, and elliptical; outer metatarsal tubercle small, round, and indistinct; subarticular tubercles round; supernumerary tubercles small, in single row on proximal segments of each digit; toes moderately long and slender; length of toes from shortest to longest, 1-2-5-3-4, the fifth nearly as long as third; toes nearly fully webbed; web extending to base of penultimate phalanx of fourth toe and to discs on other toes; discs small, about two-thirds size of those on fingers. Anal opening above middle of thighs; anal sheath short, deeply creased medially; heavy transverse dermal fold above anus; no large anal tubercles. Skin of all dorsal surfaces, chin, and ventral surfaces of limbs, except proximal parts of thighs, smooth; belly and proximal parts of thighs areolate; thoracic fold present, weak. Tongue elliptical, slightly longer than wide, not notched behind, and free posteriorly for about one-fourth of its length; vomerine teeth 3-3, situated on small, widely separated, transverse ridges between rather small elliptical inner nares; no vocal slits. Color (in alcohol) dark brown with irregular darker reticulations on dorsal surfaces of head, body, and limbs; flanks brown with small creamy white spots; posterior surfaces of thighs dark brown; chin creamy tan; belly grayish brown with cream-colored flecks; ventral surfaces of limbs pale brown; webbing on feet gray; small white spots in anal region. Color (in life) chocolate brown with darker brown reticulations and irregular blotches above; flanks brown with yellow spots; belly gray to grayish brown with faint cream-colored spots; iris a deep bronze color. _Variation._--In males the total number of vomerine teeth varies from 4 to 7. In many specimens the vomerine ridges are larger and more closely approximated medially than in the specimen described above. Females attain snout-vent lengths of 51 mm., have as many as 9 vomerine teeth, and have a proportionately larger tympanum than males. Some of the largest specimens of both sexes have indistinct cream-colored pustules scattered on the ventral surface of the forearm. Some individuals have nearly uniform grayish brown ventral surfaces; in others the chin, as well as the abdomen, is brown with cream-colored spots. The dorsal surfaces of some specimens are nearly uniform dark brown with no reticulations. In others the dorsum is paler brown with distinct darker mottling; in some of these there is little mottling laterally, so that there is the effect of an irregular, pale brown, dorsolateral stripe. _Tadpoles._--The tadpoles of this species were described by Rabb and Mosimann (1955). Tadpoles obtained from streams at 3.3 kilometers north and at 8.5 kilometers southeast of Zacualtipán, Hidalgo, are like those described by Rabb and Mosimann in having 2/3 tooth rows, peglike serrations on the beaks, and long rounded tails. The largest tadpole (KU 60078) has small hind legs, a body length of 22 mm., and a total length of 61 mm. _Remarks._--Taylor (1940:393) found frogs of this species in plants along small spring-fed rivulets in an open meadow at El Chico Parque Nacional. Also, he noted that active frogs dove into the streams and took refuge in the mud on the bottom. Rabb and Mosimann (1955:1) found this species along banks of tiny streams in open meadows and noted that the frogs sought refuge in the water. At El Chico Parque Nacional on June 8, 1960, I found _Hyla robertsorum_ under rocks along small rivulets by day; at night, when the temperature was 14° C., frogs were sitting on rocks and in junipers overhanging a small stream. At the same locality on June 23 and 24, 1962, frogs of this species were found on rainy nights, when the temperature varied from 10 to 12° C. At this time the frogs were sitting on the grassy banks of rivulets in the meadow. During the day _Hyla robertsorum_ was found on the earthen banks of the rivulets in places where dense growths of grass overhung the streams. On December 23, 1959, one specimen of _Hyla robertsorum_ was found beneath a rock in a small stream in pine forest at 3.3 kilometers north of Zacualtipán. Rabb and Mosimann (1955:1) obtained tadpoles of _Hyla robertsorum_ from quiet pools of a stream at El Chico Parque Nacional. I found tadpoles in pools in rocky streams in pine forest at 3.3 kilometers north and at 8.5 kilometers southeast of Zacualtipán. Four completely metamorphosed juveniles obtained on June 8, 1960, at El Chico Parque Nacional have snout-vent lengths of 30.6 to 32.0 mm. Gravid females were found at the same locality on June 8, 1960, and June 23, 1962. [Illustration: FIG. 4. Map showing locality records for _Hyla crassa_, _Hyla pachyderma_, and _Hyla robertsorum_.] _Distribution.--Hyla robertsorum_ inhabits streams in the pine and fir forests in the higher parts (2250 to 3050 meters) of the Sierra Madre Oriental in extreme northern Puebla and eastern Hidalgo (Fig. 4). Specimens examined.--HIDALGO: 16 km. W Agua Blanca, UMMZ 106432 (6); El Chico Parque Nacional, CNHM 75786, 100124, KU 57650-71, 59824-5 (skeletons), 59914-5 (skeletons), 71269-95, 71757 (skeleton), UIMNH 10349-64, 27022-35, 39434-49, UMMZ 92462, 106401 (5), 106443 (tadpoles), USNM 114762-85, 134268; 3.3 km. N Zacualtipán, KU 53810, 60078 (tadpoles); 8.5 km. SE Zacualtipán, KU 60079 (tadpoles). PUEBLA: Honey, UMMZ 95245. #Hyla pachyderma# Taylor _Hyla pachyderma_ Taylor, Univ. Kansas Sci. Bull., 28:308-310, pl. 27, figs. 1-4, November 12, 1942 [Holotype.--USNM 115029 from Pan de Olla, Veracruz, south of Tezuitlán, Puebla, México; Hobart M. Smith collector]. Taylor and Smith, Proc. U. S. Natl. Mus., 95:588, June 30, 1945. Smith and Taylor, Bull. U. S. Natl. Mus., 194:86, June 17, 1948; Univ. Kansas Sci. Bull, 33:350, March 20, 1950. Rabb and Mosimann, Occ. Papers Mus. Zool. Univ. Michigan, 563:7-8, March 29, 1955. _Diagnosis._--Maximum snout-vent length in males 40 mm.; snout in dorsal profile round; tarsal fold strong; inner metatarsal tubercle round and moderate in size; outer metatarsal tubercle small and indistinct; webbing on foot extending to middle of penultimate phalanx of fourth toe; nuptial spines on thumb large; thoracic fold present; anal opening at level of middle of thighs; dorsum dull grayish brown with scattered indistinct dark flecks; venter cream-color mottled with brown on throat and chest; flanks grayish brown with cream-colored reticulations; anal stripe distinct, creamy white, sometimes extending outward on thighs; white spots or line below anus; vocal slits absent. _Description._--The following description is based on USNM 115028 from Pan de Olla, Veracruz. Adult male having a snout-vent length of 39.9 mm.; tibia length, 21.0 mm., 52.6 per cent of snout-vent length; foot length (measured from proximal edge of inner metatarsal tubercle to tip of longest toe), 20.5 mm.; greatest width of head, 12.8 mm., 32.1 per cent of snout-vent length; head length, 12.3 mm., 30.8 per cent of snout-vent length. Snout short, in lateral profile bluntly rounded, in dorsal profile rounded; canthus rounded; loreal region slightly concave; lips thick, round, and not flaring; nostrils slightly protuberant; internarial distance, 2.7 mm.; interorbital distance, 3.7 mm., somewhat broader than eyelid, 2.9 mm. A heavy dermal fold from posterior corner of eye above tympanic region and then to insertion of forearm; tympanum completely concealed. Forearm moderately robust; distinct fold on wrist; prepollex enlarged bearing cluster of moderate-sized, horny, nuptial spines continuous on edge of digit; row of spines present on second finger; subarticular tubercles round, small proximally and slightly larger distally; supernumerary tubercles small and indistinct; three palmar tubercles, median and outer partly fused; fingers long, moderately slender; discs moderately large; length of fingers from shortest to longest, 1-2-4-3; second and fourth fingers subequal in length; webbing between fingers rudimentary. Heels overlap by about one-fourth length of shank when hind limbs adpressed; tibiotarsal articulation extends to anterior edge of eye; tarsal fold thick, low, extending nearly to heel; inner metatarsal tubercle moderately large and round; outer metatarsal tubercle small and indistinct; subarticular tubercles small and round; supernumerary tubercles small, present on proximal segments of digits; toes moderately long and slender; length of toes from shortest to longest, 1-2-3-5-4; third and fifth toes subequal in length; toes about three-fourths webbed; web extending to middle of penultimate phalanx of fourth toe; discs rather small, about two-thirds size of those on fingers. Anal opening directed posteroventrally at level of middle of thighs; anal flap slightly elongate; thick, transverse dermal fold above anus. Skin of dorsum and ventral surfaces of limbs, except thighs, smooth; skin of chin, belly, and ventral surfaces of thighs granular; thoracic fold present. Tongue nearly round, slightly notched behind, and barely free posteriorly; vomerine teeth 3-3, situated on posteroventral edges of small, transverse vomerine ridges between rather large triangular inner nares; no vocal slits. Color (in alcohol) of dorsal surfaces of head, body, and limbs dull grayish brown with indistinct scattered darker flecks; flanks grayish brown with cream-colored reticulations; posterior surfaces of thighs tan; chin cream-color, mottled with brown; belly creamy yellow; anal stripe cream-color. _Variation._--In addition to the specimen described above three others are known. One is a juvenile having a snout-vent length of 29.5 mm., and two are females having snout-vent lengths of 46.9 and 41.6 mm. Variation in structure and coloration between the four specimens is slight. In the females the tympani are partly visible and are about one-third the diameter of the eye; the chest is mottled with brown; the anal stripe extends laterally in the form of a row of cream-colored dashes and spots onto the posterodorsal surfaces of the thighs. _Remarks._--On the basis of the four specimens available for study, _Hyla pachyderma_ seems to be closely related to _Hyla crassa_ and _Hyla robertsorum_. In the _Hyla bistincta_ group, _Hyla pachyderma_ is unique in having enlarged nuptial spines. Taylor and Smith (1945:588) stated that the frogs were found on bushes and weeds beside a small, bounding stream near Pan de Olla. I have searched unsuccessfully for this species in the area around Pan de Olla and Tezuitlán. _Distribution._--This species is known only from a stream at an elevation of about 1600 meters on the Atlantic slopes of the Sierra Madre Oriental in central Veracruz (Fig. 4). Specimens examined.--VERACRUZ: Pan de Olla, south of Tezuitlán, Puebla, USNM 115026-9. #Hyla crassa# (Brocchi) _Cauphias crassus_ Brocchi, Bull. Soc. Philom. Paris, ser. 7, 1:130, 1877 [Holotype.--MNHN 6331 from "Mexico;" Adolphe Boucard collector]. _Cauphias crassum_ Brocchi, Études des batraciens de l'Amérique Centrale, p. 64, pl. 12, fig. 4, 1882. Díaz de León, Indice de los batracios que se encuentran en la República Mexicana, p. 21, June, 1904. Kellogg, Bull. U. S. Nat. Mus., 160:118-120, March 31, 1932. Taylor, Univ. Kansas Sci. Bull., 26:392, November 15, 1940. Rabb and Mosimann, Occas. Papers Mus. Zool. Univ. Michigan, 563:7, March 29, 1955. _Hyla crassa_, Boulenger, Catalogue Batrachia Salientia, 2nd. Ed., p. 396, February 1, 1882. Günther, Biologia Centrali-Americana, Reptilia and Batrachia, p. 281, September, 1901. Nieden, Das Tierreich, Amphibia, Anura 1, p. 248, June, 1923. Smith and Taylor, Bull. U. S. Natl. Mus., 194:86, June 17, 1948. Taylor, Amer. Mus. Novitates, 1437:20, December 7, 1949. _Hypsiboas crassus_, Cope, Bull. U. S. Natl. Mus., 32:14, 1887. _Hyla robustofemora_ Taylor, Univ. Kansas Sci. Bull., 26:389-393, figs. 3-4, November 27, 1940 [Holotype.--UIMNH 25050 (formerly EHT-HMS 16314) from Cerro San Felipe, 15 kilometers northeast of Oaxaca, Oaxaca, México; Edward H. Taylor collector]; Univ. Kansas Sci. Bull., 28:310, November 15, 1942. Smith and Taylor, Bull. U. S. Natl. Mus., 194:86, June 17, 1948. Taylor, Amer. Mus. Novitates, 1437:20, December 7, 1949. Smith and Taylor, Univ. Kansas Sci. Bull., 33:339, March 20, 1950. Rabb and Mosimann, Occas. Papers Mus. Zool. Univ. Michigan, 563:7, March 29, 1955. _Plectrohyla crassa_, Hartweg, Occas. Papers Mus. Zool. Univ. Michigan, 437:1, June 30, 1941. Stuart, Occas. Papers Mus. Zool. Univ. Michigan, 455:6, January 5, 1942. _Diagnosis._--Maximum snout-vent length in males 54 mm.; snout in dorsal profile round; tarsal fold strong; inner metatarsal tubercle small and elliptical; outer metatarsal tubercle small, flat, and indistinct; foot fully webbed; nuptial spines on thumb small; thoracic fold absent; anal opening at level of middle of femur; dorsum dull olive-green; belly creamy yellow; chin gray with yellow flecks; flanks dull olive-green with scattered cream-colored spots; and stripe faint, cream-color; vocal slits absent. _Description._--The following description is based on UIMNH 25050 from Cerro San Felipe, Oaxaca. Adult male having a snout-vent length of 53.7 mm.; tibia length, 26.9 mm., 50.1 per cent of snout-vent length; foot length (measured from proximal edge of inner metatarsal tubercle to tip of longest toe), 25.4 mm.; greatest width of head, 17.6 mm., 32.8 per cent of snout-vent length; head length, 16.0 mm., 29.8 per cent of snout-vent length; diameter of eye, 5.4 mm.; diameter of tympanum, 1.5 mm., 27.8 per cent of diameter of eye. Snout short, in lateral profile bluntly rounded, in dorsal profile broadly round; canthus absent; loreal region nearly flat; lips thick and not flaring; nostrils barely protuberant; internarial distance, 3.8 mm.; interorbital distance, 4.7 mm., somewhat broader than width of eyelid, 3.8 mm. Heavy dermal fold from posterior corner of eye above tympanum and then to insertion of forearm; tympanum concealed above, its diameter about equal to its distance from eye. Forearm thick; distinct fold on wrist; prepollex enlarged bearing patch of small nuptial spines continuous on side of digit; similar patch on second finger; subarticular tubercles small and round, none bifid; few supernumerary tubercles on proximal segments of digits; large, flat palmar tubercle; fingers long and slender; length of fingers from shortest to longest, 1-2-4-3; discs moderately large; rudimentary web between second and third fingers and between third and fourth. Legs thick; heels overlap by about one-fourth length of shank when hindlimbs adpressed; tibiotarsal articulation extends to posterior corner of eye; tarsal fold thick, extending to heel; inner metatarsal tubercle small and elliptical; outer metatarsal tubercle small, flat, and indistinct; subarticular tubercles small and round; single row of supernumerary tubercles on proximal segments of each digit; toes moderately short and slender; length of toes from shortest to longest, 1-2-3-5-4; toes fully webbed; flap of skin on inner surface of first toe; discs about same size as those on fingers. Anal opening directed posteroventrally at middle of thighs; anal sheath moderately elongate; small tubercles below anal opening. Skin of dorsum rather smooth, somewhat granular on dorsal surfaces of limbs; skin of chin and belly moderately granular; that of posterior surfaces of thighs smooth; no thoracic fold. Tongue nearly round, shallowly notched posteriorly, and free for about one-fourth its length; vomerine teeth 5-5, situated on rounded ridges between small inner nares; no vocal slits. Color (in alcohol) dull olive-green on dorsal surfaces of head, body, and limbs; flanks dull olive-green with scattered cream-colored spots; posterior surfaces of thighs grayish brown with faint creamy mottling; chin gray with cream-colored spots; belly creamy yellow, suffused with gray posteriorly; undersides of feet and webbing gray; anal stripe faint, pale cream-color. _Variation._--The only other known specimen (MNHN 6331) is a female having a snout-vent length of 53.7 mm. and resembling the specimen described above in most details of morphology. In MNHN 6331 the tympanum is completely concealed, and the 8-7 vomerine teeth are arranged in two irregular rows. The female has more cream-colored mottling on the flanks and posterior surfaces of the thighs and more distinct mottling on the throat than the male described above. _Remarks._--The systematic status of _Cauphias crassus_ Brocchi has been in doubt since the time of the original description. Brocchi (1877:130) stated: "Les dernieres phalanges sont obtuses, tronqués a leur extrémité antérieure." Brocchi placed the species in his genus _Cauphias_ (type species, _C. guatemalensis_), which he considered to be related to _Hylodes_ ( = _Eleutherodactylus_ in the sense used by Brocchi); he thereby placed _Cauphias_ in his Hylodidae ( = Leptodactylidae, in part). This idea of relationships was perpetuated by Barbour (1927:96), who reported on the second known specimen of _Cauphias guatemalensis_ and stated: "When I dissected the sternum I was at once struck by its similarity to Noble's figures of transitional types between arciferal and firmisternal forms. The _Cauphias_ sternum recalls some of his figures for _Sminthillus_ and _Eleutherodactylus_. This genus is probably most closely related to the latter and has probably become highly modified to meet some peculiar environmental condition or on account of some specialized habits as yet unknown." Kellogg (1932:118) placed _Cauphias_ in the Leptodactylidae and stated that the terminal phalanges are T-shaped. Hartweg (1941:1) considered _Plectrohyla_ to be the correct generic name for _Cauphias guatemalensis_; he thereby relegated _Cauphias_ to the synonomy of _Plectrohyla_. Hartweg (1941:9) further showed that the terminal phalanges of _Plectrohyla guatemalensis_ were not T-shaped and that intercalary cartilages were present. Thus, he correctly concluded that _Plectrohyla guatemalensis_ (and _P. crassa_ by implication) was a member of the family Hylidae. Stuart (1942:6) followed Hartweg's allocations and further suggested that _Plectrohyla crassa_ might be the same species as _Hyla robustofemora_ Taylor. In his description of _H. robustofemora_ Taylor (1940:392), who had not examined the type of _Cauphias crassus_, stated that were it not for the statements of Brocchi and Kellogg that _C. crassus_ has T-shaped terminal phalanges, "I might suspect I had before me a specimen of _Cauphias_ closely related to _crassum_." I have compared the type of _Cauphias crassus_ with that of _Hyla robustofemora_. With the exception of the minor differences mentioned in the preceding section on variation, the specimens are alike, leaving little doubt that they represent the same species. The statements of Brocchi and Kellogg to the contrary, the type of _Cauphias crassus_ possesses intercalary cartilages between the penultimate and terminal phalanges; the latter are not T-shaped, but as in the type of _Hyla robustofemora_, resemble those typical of _Hyla_. On the basis of the morphological characters, as pointed out for _Hyla robustofemora_ by Taylor (1940:392), _Hyla crassa_ is a member of the _Hyla bistincta_ group. _Distribution._--This species is definitely known only from a small stream at an elevation of 2300 meters in the mountains of central Oaxaca (Fig. 4). Specimens examined.--OAXACA: Cerro San Felipe, UIMNH 25050. "Mexico," MNHN 6331. RELATIONSHIPS The evolutionary trend in the members of the _Hyla bistincta_ group is towards aquatic habits. _Hyla bistincta_, the least specialized species in the group, has relatively short fingers, webbing between the fingers, a truncate, high snout, and relatively large subarticular and supernumerary tubercles. _Hyla charadricola_ resembles _bistincta_ in having relatively short fingers, a slight amount of webbing, and a truncate snout. Apparently these two species are more closely related to one another than either is to the other species in the group. _Hyla robertsorum_, _pachyderma_, and _crassa_ are the most aquatic members of the group. These species are closely related, possibly conspecific. All have round, sloping snouts, robust forearms, long, unwebbed fingers, and large webbed feet. Both _H. pachyderma_ and _H. crassa_ seem to be advanced beyond _H. robertsorum_. If small nuptial spines, moderately webbed feet, and absence of a well-defined thoracic fold are considered to be less advanced than large nuptial spines and a strong thoracic fold, as in _H. pachyderma_, or fully webbed feet, as in _H. crassa_, then _H. robertsorum_ must be considered to be less advanced than _H. pachyderma_ or _H. crassa_. Members of the _Hyla bistincta_ group inhabit mountain streams. The frogs can be found along these streams throughout the year. Since in most stream-breeding hylids there is no migration to breeding sites, the breeding call does not function to attract females to the breeding site. Apparently voices are lacking in all members of the _Hyla bistincta_ group, except in _Hyla bistincta_. The presence of vocal slits and the ability to call further indicate that _Hyla bistincta_ is the primitive member of this group. Members of the _Hyla bistincta_ group and the species of _Plectrohyla_ closely resemble each other in osteology and body form of the adults and in structure of the tadpoles. This resemblance suggests a close relationship between the two groups. _Plectrohyla_ apparently evolved from an ancestral stock resembling the extant _Hyla bistincta_. Probably this stock gave rise independently to _Plectrohyla_ and to the _Hyla robertsorum-pachyderma-crassa_ complex. In the former the voice was retained, and a projecting prepollex spine developed, whereas in the latter the voice was lost, and the prepollex spine did not project. _Plectrohyla_ lives in mountain streams in the Chiapan-Guatemalan highlands; the _Hyla robertsorum-pachyderma-crassa_ complex inhabits similar environments in the Sierra Madre Oriental in México. _Hyla charadricola_ also lives in the Sierra Madre Oriental, whereas _Hyla bistincta_ is widespread in the mountains of México southeastward to the Isthmus of Tehuantepec. LITERATURE CITED BARBOUR, T. 1927. _Cauphias_ rediscovered. Copeia, no. 165:96-98, December 23. BROCCHI, P. 1877. Note sur quelques batraciens hylaeformes recueillis au Mexique et au Guatemala. Bull. Soc. Philom. Paris, ser. 7, 1 (3):122-132. DUELLMAN, W. E. 1961. The amphibians and reptiles of Michoacán, México. Univ. Kansas Publ. Mus. Nat. Hist., 15:1-148, pls. 1-6, December 20. HARTWEG, N. 1941. Notes on the genus _Plectrohyla_, with descriptions of new species. Occas. Papers Mus. Zool. Univ. Michigan, 437:1-10, pl. 1, June 30. KELLOGG, R. 1932. Mexican tailless amphibians in the United States National Museum. Bull. U. S. Natl. Mus., 160:iv + 224 pp., pl. 1, March 31. RABB, G. B. and MOSIMANN, J. E. 1955. The tadpole of _Hyla robertsorum_, with comments on the affinities of the species. Occas. Papers Mus. Zool. Univ. Michigan, 563:1-9, March 29. SHANNON, F. A. 1951. Notes on a herpetological collection from Oaxaca and other localities in Mexico. Proc. U. S. Natl. Mus., 101:465-484, May 17. STUART, L. C. 1942. Descriptions of two new species of _Plectrohyla_ Brocchi, with comments on several forms of tadpoles. Occas. Papers Mus. Zool. Univ. Michigan, 455:1-14, January 5. TAYLOR, E. H. 1940. New species of Mexican Anura. Univ. Kansas Sci. Bull., 41:385-405, November 27. 1948. A new hylid frog from eastern Mexico. Univ. Kansas Publ. Mus. Nat. Hist., 1:259-262, August 16. 1949. A new hylid frog from central Veracruz. Copeia, 1949 (4):272-274, pl. 1, December 15. TAYLOR, E. H. and SMITH, H. M. 1945. Summary of the collections of amphibians made in México under the Walter Rathbone Bacon Traveling Scholarship. Proc. U. S. Natl. Mus., 95:521-613, pls. 18-32, June 30. _Transmitted June 24, 1963._ 29-8590 
37350	----	University of Kansas Publications Museum of Natural History Volume 12, No. 2, pp. 155-180, 10 figs. -----------July 10, 1959--------------- The Ancestry of Modern Amphibia: A Review of the Evidence BY THEODORE H. EATON, JR. University of Kansas Lawrence 1959 University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Robert W. Wilson Volume 12, No. 2, pp. 155-180 Published July 10, 1959 University of Kansas Lawrence, Kansas PRINTED IN THE STATE PRINTING PLANT TOPEKA, KANSAS 1959 [Illustration] 27-8362 [Transcriber's Notes: Several typos have been regulated. One typo of "ancester" for "ancestor" was corrected. One instance of "salamanderlike" corrected to "salamaner-like".] The Ancestry of Modern Amphibia: A Review of the Evidence BY THEODORE H. EATON, JR. INTRODUCTION In trying to determine the ancestral relationships of modern orders of Amphibia it is not possible to select satisfactory structural ancestors among a wealth of fossils, since very few of the known fossils could even be considered possible, and scarcely any are satisfactory, for such a selection. The nearest approach thus far to a solution of the problem in this manner has been made with reference to the Anura. Watson's paper (1940), with certain modifications made necessary by Gregory (1950), provides the paleontological evidence so far available on the origin of frogs. It shows that several features of the skeleton of frogs, such as the enlargement of the interpterygoid spaces and orbits, reduction of the more posterior dermal bones of the skull, and downward spread of the neural arches lateral to the notochord, were already apparent in the Pennsylvanian _Amphibamus_ (Fig. 1), with which Gregory synonymized _Miobatrachus_ and _Mazonerpeton_. But between the Pennsylvanian and the Triassic (the age of the earliest known frog, _Protobatrachus_) there was a great lapse of time, and that which passed between any conceivable Paleozoic ancestor of Urodela and the earliest satisfactory representative of this order (in the Cretaceous) was much longer still. The Apoda, so far as known, have no fossil record. Nevertheless it should be possible, first, to survey those characters of modern Amphibia that might afford some comparison with the early fossils, and second, to discover among the known Paleozoic kinds those which are sufficiently unspecialized to permit derivation of the modern patterns. Further circumstantial evidence may be obtained by examining some features of Recent Amphibia which could not readily be compared with anything in the fossils; such are the embryonic development of the soft structures, including cartilaginous stages of the skeleton, the development and various specializations of the ear mechanism, adaptive characters associated with aquatic and terrestrial life, and so on. COMPARISON OF MODERN ORDERS WITH THE LABYRINTHODONTS AND LEPOSPONDYLS [Illustration: Fig. 1. _Saurerpeton_ (× 1/2, after Romer, 1930, fig. 6); _Amphibamus_, the palatal view × 2-1/4, from Watson, 1940, fig. 4 (as _Miobatrachus_), the dorsal view × 2-1/2, from Gregory's revised figure of _Amphibamus_ (1950, Fig. 1); _Protobatrachus_, × 1, from Watson, 1940, fig. 18, 19.] In both Anura and Urodela the skull is short, broad, relatively flat, with reduced pterygoids that diverge laterally from the parasphenoids leaving large interpterygoid vacuities, and with large orbits. (These statements do not apply to certain larval or perennibranchiate forms.) The skull in both orders has lost a number of primitive dermal bones in the posterior part; these are: basioccipital, supraoccipital, postparietal, intertemporal, supratemporal, and tabular. The exoccipitals form the two condyles but there are no foramina for the 11th and 12th nerves, since these are not separate in modern Amphibia. The opisthotic is missing in all except Proteidae (but see discussion of the ear). Although the skull is normally autostylic, a movable basipterygoid articulation is present among Hynobiid salamanders and in at least the metamorphic stages of primitive frogs, and therefore should be expected in their ancestors. The vertebrae are, of course, complete; see discussion in later section. The quadratojugal, lost in salamanders, is retained in frogs, and conversely the lacrimal, absent in frogs, occurs in a few primitive salamanders. The situation in Apoda is different, but postfrontal and jugal should be noted as bones retained in this order while lost in the others. Thus, in spite of minor differences, the above list shows that there are numerous and detailed similarities between Anura and Urodela with respect to the features in which they differ from the Paleozoic orders. Pusey (1943) listed 26 characters which _Ascaphus_ shares with salamanders but not with more advanced frogs; a few of these might be coincidental, but most of them are of some complexity and must be taken to indicate relationship. The main adaptive specializations of Anura, however, including loss of the adult tail, extreme reduction in number of vertebrae, formation of urostyle, elongation of the ilium and lengthening of the hind legs, must have appeared at a later time than the separation of that order from any possible common stem with Urodela, although they are only partially developed in the Triassic _Protobatrachus_. Turning to the Paleozoic Amphibia, there are two groups in which some likelihood of a relationship with modern order exists. In the Pennsylvanian Trimerorhachoidea (Labyrinthodontia, order Temnospondyli) some members, such as _Eugyrinus_, _Saurerpeton_, and notably _Amphibamus_ (Fig. 1) had short, broad heads, an expansion of palatal and orbital openings, posterior widening of the parasphenoid associated with divergence of the pterygoids, a movable basipterygoid articulation, and reduction in size (but not loss) of the more posterior dermal bones of the skull. In recognition of Watson's (1940) evidence that these animals make quite suitable structural ancestors of frogs, Romer (1945) placed _Amphibamus_ in an order, Eoanura, but Gregory (1950) indicated that it might better be left with the temnospondyls. Association of the urodele stem with this group does not seem to have been proposed hitherto. The other group of Paleozoic Amphibia that has been considered probably ancestral to any modern type is the subclass Lepospondyli, containing three orders, Aistopoda, Nectridia and Microsauria. In these the vertebrae are complete (holospondylous), the centra presumably formed by cylindrical ossification around the notochord, and there is no evidence as to the contributions from embryonic cartilage units. It is important to note at this point that precisely the same statement can be made regarding the vertebrae of _adults_ of all three Recent orders, yet for all of them, as shown in a later section, we have ample evidence of the part played by cartilage elements in vertebral development. Therefore (a) we cannot say that there were no such elements in embryonic stages of lepospondyls, and (b) it would take more than the evidence from adult vertebrae to relate a particular modern order (for example, Urodela) to the Lepospondyli. Vague similarities to Urodela have been noted by many authors in the Nectridia, Aistopoda and Microsauria, but these are not detailed and refer mainly to the vertebrae. The skulls do not show, either dorsally or in the palate, any striking resemblance to those of generalized salamanders, and certainly most known lepospondyls are too specialized to serve as the source of Urodela. It is true that the elongate bodies, small limbs, and apparent aquatic habitus of some lepospondyls accord well with our usual picture of a salamander, but such a form and way of life have appeared in many early Amphibia, including the labyrinthodonts. The family Lysorophidae (Fig. 2), usually placed among microsaurs, is sufficiently close in skull structure to the Apoda to be a possible ancestor of these, but it probably has nothing to do with Urodela, by reason of the numerous morphological specializations that were associated with its snakelike habitus. [Illustration: Fig. 2. _Lysorophus tricarinatus_, lateral and posterior views × 2-1/2, modified after Sollas, 1920, Figs. 8 and 12, respectively; palatal view after Broom, 1918, × 1-1/2. For explanation of abbreviations see Fig. 3.] McDowell's (1958) suggestion that it would be profitable to look among the Seymouriamorpha for the ancestors of frogs seems to be based upon a few details of apparent resemblance rather than a comprehensive view of the major characters of the animals. In most points which he mentions (limb girdles, form of ear, pterygoid articulation) the present writer does not see a closer similarity of frogs to Seymouriamorpha than to Temnospondyli. Still other opinions have been expressed. Herre (1935), for instance, concludes "on anatomical, biological and paleontological grounds" that the orders of Urodela, Anura, Apoda and Stegocephali were all independently evolved from fish, but beyond citing the opinions of a number of other authors he does not present tangible evidence for this extreme polyphyletic interpretation. More notable are the views of several Scandinavian workers (Säve-Söderbergh, 1934; Jarvik, 1942; Holmgren, 1933, 1939, 1949a, b), of whom Jarvik, in a thorough analysis of the ethmoid region, would derive the Urodela from Porolepid Crossopterygii, and all other tetrapods from the Rhipidistia; Säve-Söderbergh and Holmgren, the latter using the structure of carpus and tarsus, see a relationship of Urodela to Dipnoi, but accept the derivation of labyrinthodonts and other tetrapods from Rhipidistia. All of this work is most detailed and laborious, and has produced a great quantity of data useful to morphologists, but the diphyletic theory is not widely adopted; the evidence adduced for it seems to consist largely of minutiae which, taken by themselves, are inconclusive, or lend themselves to other interpretation. For instance Holmgren's numerous figures of embryonic limbs of salamanders show patterns of cartilage elements that he would trace to the Dipnoan type of fin, yet it is difficult to see that the weight of evidence requires this, when the pattern does not differ in any fundamental manner from those seen in other embryonic tetrapods, and the differences that do appear may well be taken to have ontogenetic rather than phylogenetic meaning. Further, the Dipnoan specialization of dental plates and autostylic jaw suspension, already accomplished early in the Devonian, would seem to exclude Dipnoi from possible ancestry of the Urodela, an order unknown prior to the Mesozoic, in which the teeth are essentially similar to those of late Paleozoic Amphibia, and the jaw suspension is not yet in all members autostylic. THE EAR [Illustration: Fig. 3. Occipital region of skulls of _Megalocephalus brevicornis_ (× 3/10, after Watson, 1926, as _Orthosaurus_), _Dvinosaurus_ (× 1/4, modified after Bystrow, 1938; the lower figure after Sushkin, 1936), and _Necturus maculosus_ (× 3, original, from K. U., No. 3471). Abbreviations Used in Figures b'd.c.--basidorsal cartilage (neural arch) b'oc.--basioccipital ce._{1-4}--centrale_{1-4} ch.--ceratohyal clav.--clavicle clei.--cleithrum cor.--coracoid d.c._{1-4}--distal carpal_{1-4} diap.--diapophysis exoc.--exoccipital ep.--episternum hyost.--hyostapes i.--intermedium Mk.--Meckel's cartilage n.--notochord om.--omosternum op.--operculum opis.--opisthotic par.--parietal par. proc.--paroccipital process peri. cent.--perichordal centrum p'p.--postparietal prep.--prepollex pro.--prootic p'sp.--parasphenoid pt.--pterygoid p.t.f.--post-temporal fossa postzyg.--postzygapophysis qj.--quadratojugal qu.--quadrate ra.--radiale r.hy.--hyomandibular ramus of VII rib-b.--rib-bearer r.md.--mandibular ramus of VII sc.--scapula sc'cor.--scapulocoracoid s'd.--supradorsal cartilage s'd.(postzyg.)--supradorsal (postzygapophysis) soc.--supraoccipital sp.c.--spinal cord sq.--squamosal s'sc.--suprascapula s't.--supratemporal sta.--stapes ster.--sternum tab.--tabular uln.--ulnare v.a.--vertebral artery xiph.--xiphisternum I,IV--digits I and IV V, VII, X, XII--foramina for cranial nerves of these numbers (in Fig. 4, VII is the facial nerve) ] In temnospondylous Amphibia the tympanum generally occupied an otic notch, at a high level on the skull, bordered dorsomedially by the tabular and ventrolaterally by the squamosal. In this position the tympanum could receive airborne sounds whether the animal were entirely on land or lying nearly submerged with only the upper part of its head exposed. Among those Anura in which the ear is not reduced the same is true, except that the tabular is lost. In Temnospondyli (Fig. 3) the posterior wall of the otic capsule was usually formed by the opisthotic, which extended up and outward as a buttress from the exoccipital to the tabular, and sometimes showed a paroccipital process for the insertion, presumably, of a slip or tendon of the anterior axial musculature. The stapes, in addition to its foot in the fenestra ovalis and its tympanic or extrastapedial process to the tympanum, bore a dorsal process (or ligament) to the tabular, an "internal" process (or ligament) to the quadrate or an adjacent part of the squamosal, and a ligament to the ceratohyal. Some of these attachments might be reduced or absent in special cases, but they seem to have been the ones originally present both phylogenetically and embryonically in Amphibia. Among typical frogs (Fig. 4) the base, or otostapes, is present and bony, the extrastapedial process (extracolumella, or hyostapes) is usually cartilaginous, the dorsal process (processus paroticus) is of cartilage or ligament, but the other two attachments are absent in the adult. The exoccipital extends laterally, occupying the posterior face of the otic capsule. Between it and the otostapes is a small disc, usually ossified, the operculum, which normally fits loosely in a portion of the fenestral membrane, and is developed from the otic capsule. The opercularis muscle extends from this disc to the suprascapula, in many but by no means all families of Anura. [Illustration: Fig. 4. Diagram of middle ear structures in _Rana_ (upper figure, after Stadtmüller, 1936, and lower left after DeBeer, 1937), and _Ambystoma_ (lower right, after DeBeer, 1937); all × 4. For explanation of abbreviations see Fig. 3.] Among Urodela (Fig. 4) the middle ear cavity and tympanum are lacking, and the stapes (columella) consists of no more than its footplate and the stylus, which is attached to the border of the squamosal, thus corresponding to the "internal" process. In families in which individuals metamorphose and become terrestrial (Hynobiidae, Ambystomidae, Salamandridae, Plethodontidae), an operculum and opercularis muscle appear in the adult, just as in frogs, except that in Plethodontidae, the most progressive family, the operculum fuses with the footplate of the stapes. Among neotenous or perennibranchiate urodeles there is no separate operculum or opercularis. The evidence given by Reed (1915) for fusion of the operculum with the columella in _Necturus_ appears inconclusive, in spite of the great care with which his observations were made. On the other hand, _Necturus_ and _Proteus_ alone among living salamanders have a distinct opisthotic on the posterior wall of the otic capsule (Fig. 3), as do the Cretaceous _Hylaeobatrachus_ and the Eocene _Palaeoproteus_. Probably these Proteidae should be regarded as primitive in this respect, although many other features may be attributed to neoteny. There is a contrast between Anura and most Urodela in the relative positions of the stapes and facial nerve, as shown in DeBeer's (1937) diagrams. In the latter (_Ambystoma_) the nerve is beneath, and in the former (_Rana_) above, the stapes. Judging by figures of _Neoceratodus_, _Hypogeophis_, and several types of reptiles and mammals, the Urodela are exceptional. _Necturus_, however, has the nerve passing above its stapes, and this may be primitive in the same sense as the persistent opisthotic. There can be, of course, no question of the nerve having worked its way through or over the obstructing stapes in order to come below it in salamanders; rather, the peripheral growth of neuron fibers in the embryo must simply pursue a slightly different course among the partially differentiated mesenchyme in the two contrasting patterns. Although DeBeer (1937) shows in his figure of _Hypogeophis_ (one of the Apoda) an operculum, this is apparently a mistake. The stapes has a large footplate, and its stylus articulates with the quadrate, but no true operculum or opercularis has been described in the Apoda. The facial nerve passes above the stapes. It does not seem necessary to regard the conditions in this order as related directly to those of either salamanders or frogs, but a reduction of the stapes comparable to that in salamanders has occurred. The presence in both frogs and terrestrial salamanders of a special mechanism involving the opercularis muscle and an operculum cut out in identical fashion from the wall of the otic capsule behind the stapes seems to require some other explanation than that of a chance convergence or parallelism. Although the stapes and otic region are readily visible in a number of labyrinthodonts and lepospondyls, no indication of an operculum seems to be reported among them. But in the Triassic _Protobatrachus_ (Fig. 1), which is unmistakably a frog in its skull, pelvis and some other features, Piveteau (1937) has shown, immediately behind the foot of the stapes, a small bony tubercle, which he and Watson (1940) designated opisthotic. Very clearly it served for insertion of a muscle, and it is equally clear that the bone is a reduced opisthotic, carrying the paroccipital process already mentioned as characteristic of it in some temnospondyls. Since the remainder of the posterior wall of the otic capsule consists of cartilage, meeting the exoccipital, it may be that the opisthotic becomes the operculum in frogs. _Protobatrachus_ was too far specialized in the Anuran direction, although it still had a tail, and the forelegs and hind legs were nearly the same size, to be considered a possible ancestor of the Urodeles. But at one stage in the general reduction of the skull in the ancestry of both groups, a condition similar to that in _Protobatrachus_ may have characterized the otic region, long before the Triassic. In the argument thus far we have considered terrestrial, adult amphibians, since it is only in these that either the normal middle ear and tympanum, or the opercular apparatus, is present. But among the urodeles several neotenic types occur (this term applies also to the perennibranchs). For most of these there is nothing about the otic region that would be inconsistent with derivation, by neoteny, from known families in which adults are terrestrial; for example, _Cryptobranchus_ could have had a Hynobiid-like ancestor. But this, as mentioned above, does not hold for the Proteidae, which possess an opisthotic of relatively large size, distinctly separate from the exoccipital and prootic. Either this bone is a neomorph, which seems improbable, or there has not been in the ancestry of this particular family an episode of reduction comparable to that seen in the terrestrial families, where there is an operculum instead of a normal opisthotic. Therefore the Proteidae probably are not derived from the general stem of other salamanders, but diverged sufficiently long ago that the bones of the otic region were reduced on a different pattern. They need not be removed from the order, but, in this respect, recognized as more primitive than any other existing Urodela or Anura. A recent paper by Hecht (1957) discusses many features of _Necturus_ and _Proteus_, and shows that they are remote from each other; his evidence does not seem to prove, however, that they were of independent origin or that they need be placed in separate families. VERTEBRAE AND RIBS Development of the vertebrae and ribs of Recent Amphibia has been studied by Gamble (1922), Naef (1929), Mookerjee (1930 a, b), Gray (1930) and Emelianov (1936), among others. MacBride (1932) and Remane (1938) provide good summaries. In this section reference will be made to the embryonic vertebral cartilages by the names used for them in these studies, although the concept of "arcualia" is currently considered of little value in comparative anatomy. [Illustration: Fig. 5. Development of Anuran vertebrae. Upper left, late tadpole of _Xenopus laevis_; lower left, same just after metamorphosis; upper right, diagram of general components of primitive Anuran vertebra. (After MacBride, 1932, Figs. 35, 38, 47D, respectively.) Lower right, section through anterior portion of urostyle, immediately posterior to sacral vertebra, in transforming _Ascaphus truei_ (original, from specimen collected on Olympic Peninsula, Washington). All × 20 approx. For explanation of abbreviations see Fig. 3.] The centrum in Anura (Fig. 5) is formed in the perichordal sheath (_Rana_, _Bufo_) or only in the dorsal portion thereof (_Bombinator_, _Xenopus_). The neural arch develops from the basidorsal cartilages that rest upon, and at first are entirely distinct from, the perichordal sheath. Ribs, present as separate cartilages associated with the 2nd, 3rd and 4th vertebrae in the larvae of _Xenopus_ and _Bombinator_, fuse with lateral processes (diapophyses) of the neural arches at metamorphosis, but in _Leiopelma_ and _Ascaphus_ the ribs remain freely articulated in the adult. Basiventral arcualia have been supposed to be represented by the hypochord, a median rod of cartilage beneath the shrinking notochord in the postsacral region, which at metamorphosis ossifies to produce the bulk of the urostyle. Fig. 5, lower right, a transverse section taken immediately posterior to the sacral ribs in a transforming specimen of _Ascaphus_, shows that the "hypochord" is a mass of cartilage formed in the perichordal sheath itself, and very obviously is derived from the ventral part of postsacral perichordal centra; there are, then, no basiventral arcualia, and the discrete hypochord shown in MacBride's diagram (Fig. 5, upper right) of a frog vertebra does not actually occur below the centrum, but only below the notochord in the postsacral region. [Illustration: Fig. 6. Development of Urodele vertebrae. Upper figures, _Triton_: at left, larva at 20 mm., at right, diagram of components of vertebra (from MacBride, 1932, figs. 17, 47C). Middle figures, _Molge vulgaris_ larva: left, at 18 mm.; middle, at 20-22 mm.; right, at 25 mm. (from Emelianov, 1936, figs. 33, 36, 38 respectively). Lower figures, _Necturus maculosus_ larva: left, at 21 mm.; right, at 20 mm. (from MacBride, 1932, figs. 41.5, 41.3 respectively, after Gamble, 1922). All × 20 approx. For explanation of abbreviations see Fig. 3.] In Urodela (Fig. 6) the pattern of vertebral and rib development is more complex, and there has been much controversy over its interpretation. Neural arches and perichordal centra form in the same manner as in frogs, but with the addition in certain cases (_Triton_) of a median supradorsal cartilage, which gives rise to the zygapophyses of each neural arch. Difficulty comes, however, in understanding the relationship of the ribs to the vertebrae. Each rib, usually two-headed, articulates with a "transverse process" that in its early development seems to be separate from both the vertebra and the rib, and is therefore known, noncommittally, as "rib-bearer." This lies laterally from the centrum, neural arch, and vertebral artery; upon fusing with the vertebra it therefore encloses the artery in a foramen separate from the one between the capitulum and tuberculum of the rib (the usual location of the vertebral artery). At least four different interpretations of these structures have been suggested: (1) Naef (1929) considered the rib-bearer a derivative of the basiventral, which, by spreading laterally and dorsally to meet the neural arch, enclosed the vertebral artery. He then supposed that by reduction of the rib-bearer in other tetrapods (frogs and amniotes) the vertebrarterial foramen and costal foramen were brought together in a single foramen transversarium. The implication is that the Urodele condition is primitive, but it cannot now be supposed that Urodela are ancestral to any other group, and the rib-bearer is most probably a specialization limited to salamanders. This does not, of course, invalidate the first part of his interpretation. (2) Remane (1938), noting that rib insertions of early Amphibia are essentially as in Amniota, argued that the rib-bearer is not from the basiventral but is a neomorph which originates directly from the neural arch and grows ventrally. This he inferred mainly from Gamble's (1922) observation on _Necturus_, but his assumption that _Necturus_ is more primitive than other salamanders (such as the Salamandridae), where the pattern differs from this, is not necessarily correct. Rather, the perennibranchs are distinguished mainly by their neotenous features, and their development is likely to show simplifications which are not necessarily primitive. The suggestion of a "neomorph" ought not to be made except as a last resort, for it is simply an acknowledgment that the author does not recognize homology with any structure already known; sometimes further information will make such recognition possible. (3) Gray (1930), using _Molge taeniatus_, concluded that the normal capitulum of the rib was lost, but that the tuberculum bifurcated to make the two heads seen in Urodela, thus accounting for the failure of the costal foramen to coincide with that of the vertebral artery. This answer, too, seems to entail an unprovable assumption which should not be made without explicit evidence. (4) Finally, Emelianov (1936) regarded the rib-bearer as a rudimentary _ventral_ rib, on account of its relationship to the vertebral artery, and considered the actual rib to be a neomorph in the _dorsal_ position characteristic of tetrapod ribs in general. This argument would fit the ontogenetic picture satisfactorily, provided that (_a_) there were some evidence of ventral, rather than dorsal, ribs in early Amphibia, and (_b_) we accept the invention of another neomorph in modern Amphibia as an unavoidable necessity. Emelianov's conclusion (p. 258) should be quoted here (translation): "The ribs of Urodela are shown to be upper ribs, yet we find besides these in Urodela rudimentary lower ribs fused with the vertebral column. The ribs of Apoda are lower ribs. In Anura ribs fail to develop fully, but as rare exceptions rudiments of upper ribs appear." Of these various interpretations, that of Naef seems to involve the minimum of novelty, namely, that the rib-bearer is the basiventral, expanded and external to the vertebral artery. It is not necessary to take this modification as the ancestral condition in tetrapods, of course. The basiventral (=intercentrum) would merely have expanded sufficiently to provide a diapophysis for the tuberculum as well as the (primitive) facet for the capitulum. No neomorph appears under this hypothesis, which has the distinct advantage of simplicity. Figures of early stages in vertebral development by the authors mentioned show that the basidorsals chondrify first, as neural arches, while a separate mass of mesenchyme lies externally and ventrally from these. This mesenchyme may chondrify either in one piece (on each side) or in two; in _Molge_ the part adjacent to the centrum is ossified in the 20-mm. larva, and subsequently unites with the more dorsal and lateral cartilaginous part, while the rib, appearing farther out, grows inward to meet this composite "rib-bearer." In _Necturus_ the mesenchyme below the neural arch differentiates into a cartilage below the vertebral artery (position proper to a basiventral), a bridge between this and the neural arch, and a rib, the latter two chondrifying later than the "basiventral" proper. In the "axolotl" (presumably _Ambystoma tigrinum_) the rib-bearer grows downward from its first center of chondrification at the side of the neural arch (Emelianov, 1936). Thus it appears that the simplest hypothesis to account for the rib-bearer is that (_a_) it is the basiventral, (_b_) it is recognizable just before chondrification as a mass of mesenchyme in contact with both the notochordal sheath and the basidorsal cartilage, (_c_) it may chondrify or ossify first in its ventral portion or in its dorsal portion, the two then joining before it fuses with the rest of the vertebra, (_d_) the enclosure of the vertebral artery is a consequence of the extension of the basiventral beyond the position occupied by it in primitive Amphibia, and (_e_) there is no indication that this took place in other orders than the Urodela. It seems that the vertebrae in Urodela have at least the following components: perichordal centra, separate basidorsal cartilages, and basiventrals, which are somewhat specialized in their manner of development. The vertebrae of Anura develop in the fashion just described except that basiventrals are lacking. It would seem no more difficult to accept the derivation of salamander vertebrae from the temnospondylous type than it is in the case of frogs, if other evidence points to such an ancestry. [Illustration: Fig. 7. Vertebrae of _Eusthenopteron_ (×1) and _Ichthyostega_ (×2/3, after Jarvik, 1952), _Trimerorhachis_ (×1-1/2, after Case), and _Amphibamus_ (×10, after Watson, 1940) in lateral and end views; the two lower right-hand figures are from Watson (1940, as _Miobatrachus_); the lower left is from a cast of the "_Miobatrachus_" specimen in Chicago Natural History Museum, No. 2000, in the presacral region (original, ×10).] Fig. 7, lower right, is Watson's (1940) illustration of the anterior trunk vertebrae of _Amphibamus_ (_Miobatrachus_), in which the intercentrum is shown as a single median piece. Fig. 7, lower left, shows two of the more posterior trunk vertebrae seen as impressions in a cast of the type of "_Miobatrachus romeri_;" evidently the inter-centra were paired at about the level of the 16th vertebra, and relatively large. Gregory's (1950) figure of the type specimen of "_Mazonerpeton_" (also equivalent to _Amphibamus_) shows the anterior trunk vertebrae in relation to the ribs essentially as they appear to me in the cast of _Miobatrachus_, and rather differently from Watson's figure of the latter. Gregory is probably right in considering the specimens to represent various degrees of immaturity. So far as present information goes, then, the vertebrae of salamanders and frogs show no _clear_ evidence of derivation from those of any particular group among the early Amphibia, but their features are not inconsistent with a simplification of the pattern of Temnospondyli. [Illustration: Fig. 8. Pectoral girdles of _Protobatrachus_ (after Piveteau, 1937), _Notobatrachus_ (after Stipanicic and Reig, 1956), Ascaphus (after Ritland, 1955 a) and _Rana_ (original); all ×2. For explanation of abbreviations see Fig. 3.] PECTORAL GIRDLE Hecht and Ruibal (Copeia, 1928:242) make a strong point of the nature of the pectoral girdle in _Notobatrachus_, as described recently by Stipanicic and Reig (1955, 1956) from the Jurassic of Patagonia, and quite rightly recommend that the significance of the arciferal and firmisternal types of girdle be restudied. That of _Notobatrachus_ is said to be firmisternal; in view of the arciferal condition in the supposedly primitive _Leiopelma_, _Ascaphus_, _Bombinator_, etc., this comes as a surprise. Is the firmisternal girdle, as seen in _Rana_, _Bufo_, and others, actually the ancestral type, and has the arciferal been derived from something like this? In the figures given by Stipanicic and Reig the ossified parts of the girdle are figured in detail (Fig. 8) and Reig's discussion of it is thorough. The decision to call it firmisternal was taken with some hesitancy, for no median elements are indicated, and the position and shape of those seen is closely similar to the ossified parts in _Ascaphus_ and _Leiopelma_; there is no bony sternum or omosternum. It is safe to suppose that some cartilage lay in the midline between the clavicles and coracoids, but there is no evidence as to its extent, rigidity, or degree of overlapping if any. Apparently, then, there is not sufficient reason to infer that this Jurassic frog had a pectoral girdle comparable with the modern firmisternal type. Piveteau (1955:261) remarks that the only living Anuran that can be compared usefully with _Protobatrachus_ (Triassic) with regard to its pectoral girdle is _Ascaphus_. Again, the extent of cartilage in _Protobatrachus_ (Fig. 8) can only be inferred, and there are no median elements. The agreement with _Ascaphus_ includes the presence, in both, of a separate coracoid ossification situated posterior to the ossified "scapulocoracoid" (actually scapula). This ossification is evidently that shown in _Notobatrachus_ as "coracoid." Direct comparison of the three genera with one another suggests that if we use the term arciferal for any, we should use it for all. In the remote predecessor of Anura, _Amphibamus_ of the Pennsylvanian, the pectoral girdle was less substantial than in many of its contemporaries, but it contained the primitive median interclavicle in addition to the clavicle, cleithrum, and scapulocoracoid. (The figure of Watson, 1940, and that by Gregory, 1950, are of individuals of different ages, the latter being older.) It is clear that the paired elements of such a girdle were held rigid by their attachment to the interclavicle, _via_ the clavicles. Subsequent elimination of the interclavicle in the Anuran line of descent, and decrease of ossification, left a girdle like that of _Protobatrachus_, _Notobatrachus_, _Ascaphus_ and _Leiopelma_. But in several advanced families a more rigid median "sternum," of one or two bony pieces plus cartilage, is developed secondarily, possibly (as Cope, 1889: 247, suggested) in correlation with axillary amplexus. Among Urodela no dermal bones occur in the pectoral girdle. There is usually a scapulocoracoid ossified as a single piece, from which a thin cartilaginous suprascapula extends dorsally and a broad cartilaginous coracoid plate extends medially, overlapping the one from the opposite side; a precoracoid lobe of this reaches forward on either side, and a median, posterior "sternum" of cartilage may make contact with the edges of the two coracoids. In _Siren_ and _Amphiuma_ two centers of ossification are found for each scapulocoracoid, and in _Triton_ and _Salamandra_ three. Probably the more dorsal and lateral of these represents the primitive scapula and the other one (or two) the primitive coracoid. Comparing the girdle of a salamander with that of a frog, the closest similarity can be seen between _Ascaphus_ and a salamander in which the scapula and coracoid ossify separately. Both have the median "sternum" in contact with the coracoid plates. The major difference, of course, is the lack of clavicle and cleithrum in the salamander. CARPUS AND TARSUS In _Ascaphus_ (Ritland, 1955a; cleared and stained specimens of nearly grown males) distal carpals 1, 2, 3 and 4 are present and separate, increasing in size in the order given (Fig. 9). A prepollex rests against centrale 1; centralia 2 and 3 are fused; the radiale fuses with centrale 4, and the intermedium fuses with the ulnare; radius and ulna are fused with each other as in other frogs. The digits (and metacarpals) are considered by Ritland to be 1-4, in addition to the prepollex, rather than 2-5. [Illustration: Fig. 9. Skeleton of fore foot of _Notobatrachus_ (after Stipanicic and Reig, 1956, terminology revised) and _Ascaphus_ (after Ritland, 1955 a); all ×5. For explanation of abbreviations see Fig. 3.] In the Jurassic _Notobatrachus_ Stipanicic and Reig (1956) have shown the carpus with surprising clarity (Fig. 9). If their nomenclature of the parts be revised, we obtain a fairly close resemblance to _Ascaphus_, except that centralia 2 and 3 are not fused, distal carpals 1 and 2 do not show (which would easily be understood if they were of the size of those in _Ascaphus_, or not ossified), and the intermedium remains separate from the ulnare. In _Salamandra_ (Francis, 1934; Nauck, 1938) distal carpals 1 and 2 are fused in both larva and adult, and 3 and 4 are separate; the radiale, intermedium and ulnare are separate in the larva but the latter two fuse in the adult; centrale 1 (labelled prepollical cartilage by Francis) and centrale 2 are separate. Francis considers the digits (and metacarpals) to be 1-4. Apparently the arrangement here indicated for the larva is characteristic of other larval salamanders, except where further reduced, and reduction below the number given for the adult is common in other terrestrial forms. The radius and ulna are, of course, separate. The ossification of carpals is more likely to be complete in adult frogs than in salamanders, but some ossification of all parts named is found in several of the latter. A common ancestor of frogs and salamanders could be expected to have the following elements present and ossified in the adult: distal carpals 1-4 separate; 3 centralia; radiale, intermedium and ulnare separate. Comparison with fossils older than _Notobatrachus_ is fruitless on these points, unless we go back to forms too distant to have any special value, such as _Eryops_. This is because of inadequate preservation and because the elements are not fully ossified in many immature specimens. For the purpose of this review there is no special value in a comparison of the tarsi of frogs and salamanders, since the leaping adaptation of the former leaves very little common pattern between them. Even in _Protobatrachus_, where the legs were not yet conspicuously lengthened, the tibiale and fibulare ("astragalus" and "calcaneum" respectively) were already considerably elongated. The carpus and tarsus of _Amphibamus_ are as yet undecipherable. THE LARVA Considering the postembryonic developmental stages of modern Amphibia, there can be no doubt that a gill-bearing, four-legged larva of a salamander, in which lateral line pores and a gular fold are present, represents much more closely the type of larva found in labyrinthodonts than does the limbless, plant-nibbling tadpole of the Anura. Salamander-like larvae of labyrinthodonts are well known, especially those formerly supposed to comprise the order Branchiosauria. Many, perhaps the majority of, labyrinthodonts show some features associated with aquatic life even when full-grown, as do the lepospondyls. These features may include impressions of sensory canals on the dermal bones of the skull, persistence of visceral arches, reduction in size of appendages, and failure of tarsal and carpal elements to ossify. In fact, it appears that very few of the Paleozoic Amphibia were successful in establishing themselves as terrestrial animals even as adults. Nevertheless, in the ancestry of Anura, and that of at least the Hynobiid, Ambystomid, Salamandrid and Plethodontid salamanders, there must certainly have been a terrestrial adult, transforming from an aquatic larva. The leaping mechanism of Anura, shown in so many features of their anatomy, is perhaps to be explained as a device for sudden escape from land into the water, but it was not yet perfected in the Triassic _Protobatrachus_ or the Jurassic _Notobatrachus_. The middle ear, its sound-transmitting mechanism, and the tympanum, well developed in most Anura, are readily derived from those of early labyrinthodonts, and are presumably effective for hearing airborne sounds whether on land or while floating in the water. Reduction of these organs in Urodela may be correlated with their customary restriction to subsurface habitats and inability to maintain a floating position while in water. Some light may be shed on the significance of the tadpole of Anura by considering the early stages of the ribbed frogs, Liopelmidae. _Leiopelma_ and _Ascaphus_ are so closely similar in the adult that there is no doubt that they belong in one family, primitive in some respects (including articulated ribs; pyriformis and caudalipuboischiotibialis muscles) but not in others (absence of tympanum and middle ear). In both genera the eggs are large, 5 mm. in _Leiopelma_, 4.5 mm. in _Ascaphus_, and unpigmented; but at this point the resemblance ends. [Illustration: Fig. 10. _Leiopelma hochstetteri_ larva, lateral and ventral (after Stephenson, 1955), ×4.] Stephenson (1955) showed that embryos of _L. hochstetteri_ develop equally well on land (in damp places) or in the water, and that embryos prematurely released from egg capsules develop successfully in the water. The larvae possess both pairs of legs (Fig. 10) and a broad gular fold similar to that of larval salamanders. In _L. hochstetteri_ the fold grows back over the forelegs temporarily, but remains free from the body and presently the legs reappear, whereas in _L. archeyi_ the forelegs are not covered at any time. No branchial chamber or spiracle is formed. Of course direct development, without a tadpole, occurs in several other groups of Anura, but in each case terrestrial adaptations are obvious. This is not true of _Leiopelma_, which Stephenson regards as more nearly comparable with Urodela in its development than with other Anura, and he sees in it a "primary and amphibious" mode instead of a terrestrial specialization. The _Ascaphus_ tadpole bears no outward resemblance to the larva of _Leiopelma_, but is a normal tadpole in form, although sluggish in activity. Its greatly expanded labial folds bear numerous rows of horny epidermal "teeth," which, with the lips, serve to anchor the tadpole to stones in the swift water of mountain brooks. Noble (1927) noticed that particles of food were taken in through the external nares, and that a current of water passed through these openings and out by way of the median spiracle. It appears that any action by the teeth and jaws in scraping algae from the rocks (which were bare in the stream where I have collected _Ascaphus_) would be quite incidental, and that the lips and teeth must be primarily a clinging mechanism. Certain other mountain brook tadpoles (for example, _Borborocoetes_) show similar devices, but these are developed independently, as specializations from the usual sort of tadpole. May it not be that closure of the gill-chamber by the opercular (=gular) fold, retardation of limb development, expansion of the lips, growth of parallel rows of horny teeth, and other correlated features that make a tadpole, were brought about as an adaptation of the primitive Anuran larva to a swift-stream habitat, and that this "basic patent" then later served to admit the tadpoles of descendant types to an alga-scraping habit in quiet water as well? The tadpole, as a unique larval type among vertebrates, bears the hallmarks of an abrupt adaptive shift, such as might have occurred within the limits of a single family, and it seems difficult to imagine the enclosed branchial chamber, the tooth-rows, and lips of a familiar tadpole as having evolved without some kind of suctorial function along the way. SUMMARY The Anura probably originated among temnospondylous labyrinthodonts, through a line represented approximately by _Eugyrinus_, _Amphibamus_, and the Triassic frog _Protobatrachus_, as shown by Watson, Piveteau and others. The known Paleozoic lepospondyls do not show clear indications of a relationship with Urodela, but _Lysorophus_ may well be on the ancestral stem of the Apoda. Between Urodela and Anura there are numerous resemblances which seem to indicate direct relationship through a common stock: (1) a similar reduction of dermal bones of the skull and expansion of palatal vacuities; (2) movable basipterygoid articulation in primitive members of both orders; (3) an operculum formed in the otic capsule, with opercularis muscle; (4) many details of cranial development, cranial muscles, and thigh muscles, especially between _Ascaphus_ and the Urodela, as shown by Pusey and Noble; (5) essentially similar manner of vertebral development, quite consistent with derivation of both orders from Temnospondyli; (6) presence in the larva of _Leiopelma_ of a salamander-like gular fold, four limbs, and no suggestion of modification from a tadpole (Stephenson). LITERATURE CITED Broom, R. 1918. Observations on the genus _Lysorophus_ Cope. Ann. Mag. Nat. Hist., (9)2:232-239. Bystrow, A. P. 1938. Dvinosaurus als neotenische Form der Stegocephalen. Acta Zool., 19:209-295. Case, E. C. 1935. Description of a collection of associated skeletons of _Trimerorhachis_. Contrib. Mus. Pal. Univ. Michigan, 4:227-274. Cope, E. D. 1889. The Batrachia of North America. Bull. U. S. Nat. Mus., 34:1-525. de Beer, G. R. 1937. The development of the vertebrate skull. Pp. xxiii + 552. Oxford, Clarendon Press. de Villiers, C. G. S. 1934. Studies of the cranial anatomy of _Ascaphus truei_ Stejneger, the American "Liopelmid." Bull. Mus. Comp. Zool., 77:1-38. Emelianov, S. W. 1936. Die Morphologie der Tetrapodenrippen. Zool. Jahrb. (Anat.), 62:173-274. Francis, E. T. B. 1934. The anatomy of the salamander. Pp. xxxi + 381. Oxford, Clarendon Press. Gamble, D. L. 1922. The morphology of the ribs and the transverse processes of _Necturus maculatus_. Jour. Morph., 36:537-566. Gray, P. 1930. On the attachments of the Urodele rib to the vertebra and their homologies with the capitulum and tuberculum of the Amniote rib. Proc. Zool. Soc. London, 1930(1931):907-911. Gregory, J. T. 1950. Tetrapods from the Pennsylvanian nodules from Mazon Creek, Illinois. Am. Jour. Sci., 248:833-873. Hecht, M. E. 1957. A case of parallel evolution in salamanders. Proc. Zool. Soc. Calcutta, Mookerjee Mem.:283-292. Holmgren, N. 1933. On the origin of the tetrapod limb. Acta Zool., 14:185-295. 1939. Contributions to the question of the origin of the tetrapod limb. Acta Zool., 20:89-124. 1949a. Contributions to the question of the origin of tetrapods. Acta Zool., 30:459-484. 1949b. On the tetrapod limb problem again. Acta Zool., 30:485-508. Herre, W. 1935. Die Schwanzlurche der mitteleocänen (oberlutetischen) Braunkohle des Geiseltales und die Phylogenie der Urodelen unter Einschluss der fossilen Formen. Zoologica, 33:87, 1-5. Jarvik, E. 1942. On the structure of the snout of Crossopterygians and lower gnathostomes in general. Zool. Bidrag fran Upsala, 21:235-675. 1952. On the fish-like tail in the Ichthyostegid Stegocephalians. Meddelelser on Grønland, 114(12):1-90. Mookerjee, H.K. 1930a. On the development of the vertebral column of the Urodela. Phil. Trans. Roy. Soc. London, B 218:415-446. 1930b. On the development of the vertebral column of the Anura. Philos. Trans. Royal Soc. London, B 219:165-196. MacBride, E.W. 1932. Recent work on the development of the vertebral column. Cambridge, Biol. Rev., 7:108-148. McDowell, S.B. 1958. Are the frogs specialized seymouriamorphs? (Abstract) Anat. Rec., 132(3):472. Naef, A. 1929. Notizen zur Morphologie und Stammesgeschichte der Wirbeltiere. 15. Dreissig Thesen über Wirbelsäule und Rippen, insbesondere bei den Tetrapoden. Zool. Jahrb., 50:581-600. Noble, G. K. 1922. The phylogeny of the Salientia; I. The osteology and the thigh musculature; their bearing on classification and phylogeny. Bull. Amer. Mus. Nat. Hist., 46:1-87. 1927. The value of life-history data in the study of the evolution of the Amphibia. Annals New York Acad. Sci., 30:31-128. Piveteau, J. 1937. Un Amphibien du Trias inférieur. Essai sur l'origine et l'évolution des Amphibiens Anoures. Annales de Paléontologie, 26:135-176. 1955. Anoura. In: Traité de Paléontologie, 5:250-274. J. Piveteau, Masson et Cie, Paris. Pusey, H. K. 1943. On the head of the liopelmid frog, _Ascaphus truei_. I. The chondrocranium, jaws, arches, and muscles of a partly grown larva. Quart. Jour. Micr. Sci., 84:105-185. Reed, H. D. 1915. The sound-transmitting apparatus in Necturus. Anat. Rec., 9:581-590. Remane, A. 1936. Wirbelsäule und ihre Abkömmlinge. In: Handbuch der vergleichenden Anatomie der Wirbeltiere, L. Bolk _et al._, 4:1-206. Urban and Schwarzenberg, Berlin, Vienna. Ritland, R. M. 1955a. Studies on the post-cranial morphology of Ascaphus truei. I. Skeleton and spinal nerves. Jour. Morph., 97:119-174. 1955b. Studies on the post-cranial morphology of Ascaphus truei. II. Myology. Jour. Morph., 97:215-282. Romer, A. S. 1945. Vertebrate paleontology. 2nd edition. Pp. viii + 687. Univ. Chicago Press. 1947. Review of the Labyrinthodontia. Bull. Mus. Comp. Zool., 99:3-368. Säve-Söderbergh, G. 1934. Some points of view concerning the evolution of the vertebrates and the classification of this group. Arkiv för Zoologi, 26A:1-20. Stadtmüller, F. 1936. Kranium und Visceralskelett der Stegocephalen und Amphibien. In: Handbuch der vergleichenden Anatomie der Wirbeltiere, by L. Bolk _et al._, 4:501-698. Stephenson, N. G. 1955. On the development of the frog, _Leiopelma hochstetteri_ Fitzinger. Proc. Zool. Soc. London, 124(4):785-795. Stipanicic, P. N. and Reig, O. A. 1955. Breve noticia sobre el hallazgo de anuros en el denominado "Complejo Porfirico de la Patagonia Extraandina," con consideraciones acerca de la composicion geologica del mismo. Revista de la Asoc. Geol. Argentina, 10(4):215-233. 1956. El "complejo porfirico de la Patagonia extraandina" y su fauna de Anuros. Acta Geol. Lilloana (Univ. Nac. del Tucuman), 1:185-297. Sushkin, P. P. 1936. Notes on the pro-Jurassic Tetrapoda from U. S. S. R. III. Dvinosaurus Amalitzky, a perennibranchiate stegocephalian from the Upper Permian of North Dvina. Trav. Inst. Pal. Acad. Sci. URSS, 5:43-91. Watson, D. M. S. 1940. The origin of frogs. Trans. Roy. Soc. Edinburgh, 40(7):195-231. _Transmitted April 7, 1959._ 
34554	----	Selected Records of Reptiles and Amphibians from Kansas BY JOHN BREUKELMAN AND HOBART M. SMITH University of Kansas Publications Museum of Natural History Volume 1, No. 5, pp. 101-112 August 15, 1946 UNIVERSITY OF KANSAS LAWRENCE 1946 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Donald S. Farner, Donald F. Hoffmeister Volume 1, No. 5, pp. 101-112 Published August 15, 1946 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1946 21-2762 Selected Records of Reptiles and Amphibians from Kansas By JOHN BREUKELMAN AND HOBART M. SMITH Preparation of a handbook of reptiles and amphibians by the junior author has led to a survey of the collections of these animals at Kansas State Teachers College in Emporia. Numerous locality records of interest and importance have been accumulated there through the efforts of the senior author and a number of his students, particularly Mr. Allen Downs. The more important records, including the first record for Kansas of _Rana sylvatica_, are reported here. We have not mentioned specimens that are from counties from which the University of Kansas Museum of Natural History already has specimens. Specimens examined by Smith are indicated by an asterisk *; those identified by the late Dr. F. N. Blanchard are indicated by an encircled period ¤ (none of these specimens are now available). All other specimens here recorded have been examined either by the senior author or by Mr. Allen Downs, or by both. Specimen numbers, unless otherwise indicated, are those of the Kansas State Teachers College collection. #Triturus viridescens louisianensis# (Wolterstorff), Newt.--_Cherokee Co._: 1 mile north and 4 miles east of Crestline (No. 164).* This is a terrestrial adult, and provides the second known locality for the species in the state. #Ambystoma texanum# (Matthes), Narrow-mouthed Salamander.--_Lyon Co._: Emporia. #Ambystoma tigrinum mavortium# (Baird), Tiger Salamander.--_Lyon Co._: (No. 292); 2 miles east of Americus. _Ness Co._: Ness City (No. 591). #Scaphiopus bombifrons# Cope, Plains Spadefoot.--_Ness Co._: 4 miles west, 1.5 miles north of Ness City (No. 592). #Bufo americanus americanus# (Holbrook), American Toad.--_Chase Co._: 10 miles southwest of Saffordville. _Cherokee Co._: 4 miles southeast of Columbus. _Lyon Co._: 6 miles south of Plymouth (No. 290)*; Emporia (Nos. 442, 443).* The records from Chase and Lyon counties represent the westernmost localities for the species in Kansas. #Bufo cognatus# Say, Great Plains Toad.--_Ness Co._: 4 miles west and 1.5 miles north of Ness City (No. 594). #Bufo woodhousii woodhousii# (Girard), Rocky Mountain Toad.--_Clark Co._: 11 miles south of Bucklin (No. 401).* _Decatur Co._: Sappa Creek near Oberlin (2 spec.).* _Ford. Co._: 5 miles southwest of Dodge City (1 spec.).* _Lyon Co._: Emporia (No. 352).* _Ness Co._: Ness City (Nos. 502-504, 595, 596)*; 4 miles west, 1.5 miles north of Ness City (No. 593).* _Sheridan Co._: Sheridan County State Park (Nos. 565-568). #Acris crepitans# Baird, Northern Cricket Frog.--_Ness Co._: 4 miles west and 1.5 miles north of Ness City (Nos. 506, 507, 597-606).* #Pseudacris nigrita triseriata# (Wied), Striped Chorus Frog.--_Lyon Co._: 10 miles south of Plymouth; 3 miles north of Emporia (No. 300); 7 miles west of Olpe; 2 miles northeast of Emporia (Nos. 434-441).* _Neosho Co._: 3 miles west of Erie. #Hyla versicolor versicolor# (Le Conte), Common Tree Toad.--_Chautauqua Co._: Elk City (No. 621). #Rana catesbeiana# Shaw, Bullfrog.--_Ness Co._: 4 miles west and 1.5 miles north of Ness City (No. 607).* _Wallace Co._: 3 miles east of Sharon Springs (1 spec.).* #Rana pipiens brachycephala# Cope, Leopard Frog.--_Clark Co._: 11 miles south of Bucklin (Nos. 398-400).* _Ness Co._: 4 miles west and 1.5 miles north of Ness City (Nos. 505, 508, 509, 608).* #Rana sylvatica cantabrigensis# Baird, Wood Frog.--_Lyon Co._: extreme southwestern corner, 3 miles east of Chase County line, between the Verdigris River and the corner of the county (1 specimen, now Mus. Nat. Hist., Univ. Kans., No. 23149).* This specimen provides for the first time a basis for inclusion of the species in the fauna of Kansas. It measures 50 mm. snout to vent; hind leg from vent 80 mm.; tibia 23 mm. The ratio of hind leg to snout-vent measurement is 0.625, and that of the tibia to snout-vent measurement is 2.17. Both figures are too high for _Rana s. sylvatica_, in which the former ratio varies between 0.53 and 0.62, the latter ratio between 1.6 and 1.88. The ratios agree well with those of _R. s. cantabrigensis_, in which the former ratio varies from 0.62 to 0.75, the latter from 1.93 to 2.3. Direct comparison of the specimen with typical examples of both subspecies substantiates its allocation to _R. s. cantabrigensis_. In the vicinity of Kansas, specimens of this species are known from Missouri (St. Louis and Stone Counties only) and northwestern Arkansas (Washington County: Winslow and Prairie Grove, Mus. Nat. Hist., Univ. Kans., Nos. 16526, 18820, 18823). Reëxamination of these specimens confirms their identity as _Rana sylvatica sylvatica_ to which the Missouri specimens from Stone County undoubtedly also belong. Accordingly this race is still to be anticipated in extreme southeastern Kansas. Reference of the specimen from Lyon County to _Rana s. cantabrigensis_ presents a problem in distribution, for the race is not known from nearer Kansas than North Dakota, Minnesota, Wisconsin and southern Illinois, except for a record given by Cope (Bull. U. S. Nat. Mus., No. 34:437, 1889) from "western Missouri." Hurter (Trans. St. Louis Acad. Sci., 20:123, 1911) restricts this record to Cooper County, and presumably verifies Cope's identification. Hurter, too, recognized the other form, _R. sylvatica_, in Missouri (Marble Cave, Stone County). Cope distinguished between the two races (as they are now recognized) and recorded typical _R. sylvatica_ from St. Louis. Accordingly the specimen from Cooper County may be considered properly identified racially. It apparently is from the locality nearest to Kansas at which the race has been taken. It seems highly probable that the Kansas occurrence, and possibly those in Arkansas and Missouri also, is a relict one. It is highly improbable that the species has a continuous distribution in either state. A wider or more southern distribution in the past seems evident. The group to which it belongs certainly has had a more southern range, as indicated by Taylor's discovery in Meade County, Kansas (Univ. Kans. Sci. Bull., 28:217, 1942), of a fossil species of _Rana_ (_parvissima_), from the Upper Pliocene, presumably related to _sylvatica_. It may or may not have been a direct ancestor of the living species. #Microhyla olivacea# (Hallowell), Northern Narrow-mouthed Toad.--_Lyon Co._: 6 miles southwest of Emporia. _Wilson Co._: 7 miles northeast of Fall River. #Crotaphytus collaris collaris# (Say), Collared Lizard.--_Geary Co._: 4 miles south of Fort Riley. _Wabaunsee Co._: 2 miles northeast of Alma. #Holbrookia maculata maculata# (Girard), Earless Lizard.--_Chase Co._: 7 miles south of Saffordville (No. 350)*; 6 miles southwest of Saffordville; 1 mile south of Saffordville (No. 338)*; 10 miles southwest of Olpe. _Hodgeman Co._: Jetmore. _Lyon Co._: 5 miles south of Plymouth; 6 miles southeast of Emporia; 9 miles southwest of Emporia. _Ness Co._: 4 miles west and 1.5 miles north of Ness City (Nos. 480, 481, 484-497, 609-611)*, 6 miles west and 0.5 miles south of Ness City (Nos. 482, 483, 498).* #Sceloporus undulatus garmani# Boulenger, Northern Plains Lizard.--_Ellsworth Co._: Carneiro; 10 miles south of Ellsworth. _McPherson Co._: 4 miles west of Roxbury (No. 133). _Ness Co._: 4 miles west and 1.5 miles north of Ness City (No. 479, 612).* #Phrynosoma cornutum# (Harlan), Texas Horned Lizard.--_Ellsworth Co._: 10 miles south of Ellsworth. _Lyon Co._: 1 mile south of Emporia; 8 miles southwest of Emporia. _Saline Co._: Coronado Heights; 3 miles northwest of Lindsborg. #Ophisaurus ventralis# (Linnaeus), Glass-snake Lizard.--_Lyon Co._: Emporia; 1 mile southwest of Emporia (No. 288).* _Rooks Co._: 5 miles southwest of Stockton (No. 407).* #Cnemidophorus sexlineatus# (Linnaeus), Six-lined Racerunner.--_Ellsworth Co._: Carneiro. _Lyon Co._: 1.5 miles northwest of Reading. _Shawnee Co._: 5 miles east of Topeka (No. 14).* #Leiolopisma laterale# (Say), Brown Skink.--_Labette Co._: 7 miles northwest of Mound Valley (No. 301).* _Lyon Co._: 1.5 miles northwest of Reading. _Wilson Co._: 4 miles southwest of Coyville (No. 281).* #Eumeces fasciatus# (Linnaeus), Common Five-lined Skink.--_Bourbon Co._: 1 mile north of Fulton. _Chase Co._: 7 miles southwest of Saffordville; 6 miles south of Clements; 2 miles south of Saffordville. _Franklin Co._: 8 miles east of Ottawa; 2 miles south of Ottawa; 2 miles southwest of Lane; 4 miles east of Ottawa; 5 miles southwest of Ottawa. _Labette Co._: 2 miles southwest of Dennis; 7 miles northwest of Mound Valley. _Lyon Co._: 1.5 miles northwest of Reading. _Miami Co._: 2.5 miles south of Fontana. _Montgomery Co._: 5 miles west of Independence. _Neosho Co._: 4 miles northwest of Erie (No. 318).* #Eumeces obsoletus# (Baird and Girard), Sonoran Skink.--_Coffey Co._: 4 miles south of Gridley (No. 467).* _Ellsworth Co._: 10 miles south of Ellsworth. _Franklin Co._: 2 miles south of Lane. _Linn Co._: 0.5 miles north of Trading Post. _Lyon Co._: 1.5 miles northwest of Reading; 10 miles south of Plymouth; 2.5 miles northeast of Dunlap; 4 miles southwest of Bushong; Emporia (No. 433)*; Dunlap (No. 444).* _McPherson Co._: 4 miles west of Lindsborg. _Morris Co._: 5 miles east of Skiddy; 1 mile east of Skiddy. _Neosho Co._: 15 miles north of Parsons. _Wilson Co._: 3 miles east of Buffalo. #Eumeces septentrionalis septentrionalis# (Baird), Northern Prairie Skink.--_Chase Co._: 6 miles south of Clements; 1 mile south of Saffordville; 11 miles southwest of Olpe (No. 348). #Diadophis punctatus arnyi# (Kennicott), Prairie Ring-necked Snake.--_Bourbon Co._: 1 mile north of Fulton. _Chase Co._: 5 miles southwest of Saffordville (No. 334)*; Elmdale (No. 146)*; 3 miles west of Bazaar. _Franklin Co._: 2.5 miles southeast of Peoria; 2 miles south of Lane. _Linn Co._: 0.5 miles north of Trading Post. _Lyon Co._: 1.5 miles northwest of Reading (Nos. 6, 372)*; Emporia. _Morris Co._: 5 miles south of Council Grove (Nos. 469-472). _Neosho Co._: 4 miles northwest of Erie (No. 316).* _Osage Co._: 8 miles southwest of Auburn. _Shawnee Co._: 5 miles east of Topeka. _Wabaunsee Co._: 2 miles northeast of Alma. _Wilson Co._: 3 miles east of Buffalo. #Carphophis amoena vermis# (Kennicott), Western Worm Snake.--_Bourbon Co._: 6 miles northwest of Fort Scott. _Chase Co._: 6 miles southwest of Cottonwood Falls (No. 365).* _Geary Co._: 5 miles southwest of Wreford. _Greenwood Co._: 4 miles northwest of Lamont (Nos. 516, 517).* _Johnson Co._: 3 miles east of De Soto. _Labette Co._: 9 miles northeast of Parsons (No. 313).* _Linn Co._: 3.5 miles south of Pleasanton. _Lyon Co._: 2 miles northeast of Reading; 5 miles northwest of Emporia. _Neosho Co._: 4 miles northwest of Erie (No. 314).* _Shawnee Co._: Wakarusa. _Wilson Co._: 2 miles northwest of Neodesha (No. 322).* #Heterodon contortrix contortrix# (Linnaeus), Common Hog-nosed Snake.--_Saline Co._: Coronado Heights; 3 miles northwest of Lindsborg. #Heterodon nasicus nasicus# Baird and Girard, Western Hog-nosed Snake.--_Chautauqua Co._: Peru. _Ness Co._: 6 miles west and 0.25 miles south of Ness City (No. 501)*; 5 miles northwest of Ness City (Nos. 619, 620).* _Rooks Co._: Stockton (No. 418). _Scott Co._: Near Scott City (Nos. 511-513, 515).* #Coluber constrictor flaviventris# (Say), Blue Racer.--_Butler Co._: 3 miles south of El Dorado. _Chase Co._: 5 miles south of Saffordville (Nos. 4, 110, 122-129, 656, 657).* _Chautauqua Co._: 1 mile south of Chautauqua (No. 375).* _Geary Co._: 5 miles southwest of Wreford. _Labette Co._: 7 miles northwest of Mound Valley (No. 356).* _Lyon Co._: 5 miles northwest of Reading (No. 226)*; 2 miles west of Olpe (No. 341)*; 5 miles northwest of Emporia (No. 397)*; 17 miles southwest of Emporia (No. 655).* _McPherson Co._: 4 miles west of Roxbury. _Morris Co._: 4 miles west of Delavan. _Neosho Co._: 4 miles northwest of Erie; 8 miles southeast of Chanute. _Ness Co._: 5 miles northwest of Ness City (No. 617).* _Wilson Co._: 3 miles east of Buffalo; 2 miles northwest of Neodesha; 7 miles northeast of Fall River. #Masticophis flagellum flagellum# (Shaw), Eastern Coachwhip.--_Wilson Co._: 2 miles northwest of Neodesha (No. 302).* _Elk Co._: 5 miles west of Grenola (No. 3).* #Masticophis flagellum testaceous# (Say), Western Coachwhip.--_Ness Co._: 5 miles northwest of Ness City (No. 616).* _Rooks Co._: Stockton (Nos. 411, 412).* #Elaphe laeta laeta# (Baird and Girard), Emory Rat Snake.--_Chase Co._: 5 miles southwest of Saffordville (Nos. 117-120, 130, 326, 354)*; Wolf Creek; 2 miles northeast of Strong City (No. 366).* _Coffey Co._: 7 miles east of Lebo. _McPherson Co._: Lindsborg. _Morris Co._: 10 miles south of Council Grove (No. 230).* _Saline Co._: Salemsborg. _Wilson Co._: 3 miles east of Buffalo (No. 161).* #Elaphe obsoleta obsoleta# (Say), Pilot Black Snake.--_Atchison Co._: Atchison (No. 15).* _Labette Co._: 4 miles north of Oswego (No. 320).* _Lyon Co._: Emporia (Nos. 12, 374, 514)*; 5 miles northwest of Emporia (No. 337); 1.5 miles northwest of Reading (No. 634).* _Morris Co._: 0.5 miles north of Wilsey. _Neosho Co._: 4 miles northwest of Erie (Nos. 321, 359).* _Wabaunsee Co._: 4 miles southwest of Alma. _Wilson Co._: 7 miles northeast of Fall River. #Pituophis catenifer sayi# (Schlegel), Common Bull Snake.--_Atchison Co._: Atchison. _Chase Co._: 4 miles east of Elmdale; Toledo; 13 miles west of Emporia; Saffordville (No. 212).* _Cherokee Co._: 4 miles southeast of Columbus. _Coffey Co._: 6 miles west of Waverly. _Ford Co._: Bucklin (No. 405).* _Franklin Co._: 2 miles southwest of Lane. _Hodgeman Co._: Jetmore. _Jefferson Co._: 3 miles south of Nortonville. _McPherson Co._: Lindsborg. _Morris Co._: 3 miles southeast of Diamond Springs; 6 miles west of Council Grove; 4 miles west of Dwight; 3 miles north of Burdick; 3 miles east of Delavan. _Ness Co._: 4 miles west and 1.5 miles north of Ness City (Nos. 499, 500, 615).* _Rooks Co._: 5 miles southwest of Stockton (Nos. 409, 410).* #Lampropeltis calligaster calligaster# (Harlan), Yellow-bellied King Snake.--_Butler Co._: U. S. Highway 54 near Greenwood County line. _Coffey Co._: 13 miles east of Emporia. _Franklin Co._: 5 miles southwest of Ottawa (No. 207).* _Lyon Co._: 8 miles east of Emporia (No. 2)*; 3 miles east of Emporia; 3 miles southeast of Olpe; southwest of Emporia (No. 216); 6 miles south of Plymouth (No. 22)*; 1.5 miles northwest of Reading (No. 633).* _McPherson Co._: Western edge of Lindsborg. _Osage Co._: 4 miles northeast of Overbrook. #Lampropeltis getulus holbrooki# (Stejneger), Speckled King Snake.--_Chase Co._: 5 miles southwest of Saffordville (No. 109); 2 miles southwest of Elmdale (No. 363).* _Hodgeman Co._: Jetmore. _Lyon Co._: 5 miles east of Emporia; 4 miles southwest of Bushong (No. 200).* _Marion Co._: 4 miles east of Antelope (No. 10).* _Morris Co._: 1 mile east of Skiddy. _Woodson Co._: Lake Fegan (No. 626).* _Wilson Co._: 3 miles east of Buffalo (No. 162).* #Lampropeltis triangulum gentilis# (Baird and Girard), Western Milk Snake.--_Chase Co._: 5 miles southwest of Saffordville (Nos. 121, 131, 406).¤ _Gove Co._: Fair Grounds (No. 18). _Greenwood Co._: 4 miles southwest of Lamont (No. 376)¤; 6 miles south of Wilbur. _Scott Co._: near Scott City (No. 510).* #Lampropeltis triangulum syspila# (Cope), Red Milk Snake.--_Cherokee Co._: 3 miles east of Crestline (No. 559). _Franklin Co._: 2 miles southwest of Lane (No. 174).¤ #Sonora episcopa# (Kennicott), Great Plains Ground Snake.--_Wilson Co._: 2 miles northwest of Neodesha (Nos. 303-305, 323-325).* #Natrix erythrogaster transversa# (Hallowell), Yellow-bellied Water Snake.--_Chase Co._: 6 miles south of Clements; 6 miles southwest of Saffordville; 3 miles east of Cottonwood Falls; 10 miles east of Matfield Green; 7 miles south of Plymouth (No. 287); Elmdale Hill, 0.5 miles east of Elmdale (No. 291)*; 10 miles southwest of Olpe (No. 343).* _Lyon Co._: 9 miles south of Plymouth (No. 25); Emporia (No. 30)*; 5 miles northwest of Emporia (No. 67); 1 mile north of Hartford (No. 108)*; 7 miles southeast of Saffordville (No. 283). #Natrix grahami# (Baird and Girard), Graham Water Snake.--_Lyon Co._: Admire; 5 miles south of Plymouth (No. 19)*; 6 miles east of Emporia (No. 40)*; 0.5 miles north of Hartford (No. 85)*; 2 miles east of Emporia (No. 208)*; Emporia (No. 588).* #Natrix rhombifera# (Hallowell), Diamond-backed Water Snake.--_Lyon Co._: 1 mile south of Emporia (Nos. 218-225)*; 8 miles northwest of Emporia (Nos. 28, 29, 240, 261)*; 2 miles southeast of Emporia (Nos. 32-35)*; 5 miles northwest of Reading. #Natrix sipedon sipedon# (Linnaeus), Common Water Snake.--_Barber Co._: 8 miles west of Medicine Lodge. _Bourbon Co._: 1 mile north of Fulton (No. 184).* _Lyon Co._: 5 miles northeast of Emporia (No. 5)*; 9 miles south of Plymouth (No. 23)*; 1 mile west of Neosho Rapids; 2 miles southeast of Emporia (No. 142, 211)*; 9 miles northeast of Emporia (No. 41); 3 miles northwest of Emporia (No. 66); 8 miles northwest of Emporia (Nos. 75, 78, 241, 254, 272)*; 5 miles south of Hartford (No. 86); 1 mile north of Hartford (Nos. 91, 100); 7 miles southwest of Emporia (No. 116); Emporia (No. 239). _Morris Co._: 3 miles southwest of Council Grove. _Shawnee Co._: 4 miles east of Topeka (No. 31).* #Haldea striatula# (Linnaeus), Southern Ground Snake.--_Cherokee Co._: 3 miles east of Crestline (No. 317)*; 2 miles north of Baxter Springs; 1 mile north and 4 miles east of Crestline. #Thamnophis radix radix# (Baird and Girard), Plains Garter Snake.--_Chase Co._: 5 miles southwest of Saffordville. _Lyon Co._: Emporia (Nos. 209, 210)*; 1.5 miles northwest of Reading. _Ness Co._: 5 miles northwest of Ness City (No. 618).* #Thamnophis sauritus proximus# (Say), Western Ribbon Snake.--_Chase Co._: 1 mile south of Saffordville (No. 340).* _Lyon Co._: 2 miles southeast of Emporia (No. 38)*; 5 miles northwest of Emporia (Nos. 68-70)*; 12 miles southeast of Emporia (No. 215)*; 5 miles northwest of Reading (No. 229).* _Wilson Co._: 3 miles east of Buffalo. #Thamnophis sirtalis parietalis# (Say), Red-sided Garter Snake.--_Barber Co._: 8 miles north of Medicine Lodge. _Dickinson Co._: 1.5 miles northwest of Herington. _Lyon Co._: 2.5 miles southeast of Emporia (No. 39)*; 1 mile northeast of Emporia (Nos. 43-48)*; 5 miles northwest of Emporia (No. 71)*; 8 miles northwest of Emporia (No. 84).* _Wabaunsee Co._: 2 miles northeast of Alma. #Tropidoclonion lineatum# (Hallowell), Lined Snake.--_Chase Co._: Saffordville; 3 miles northeast of Bazaar. _Labette Co._: 1 mile north of Montana (No. 362).* _Lyon Co._: Emporia; 9 miles south and 5 miles west of Emporia. _Marion Co._: 4 miles east of Antelope (No. 11).* _Morris Co._: 3 miles east of Woodbine (Nos. 518-520).* _Rooks Co._: 5 miles northwest of Stockton (Nos. 414, 415).* #Tantilla gracilis# Baird and Girard, Slender Tantilla.--_Cherokee Co._: 3 miles east of Crestline (Nos. 540-544). _Geary Co._: 4 miles south of Fort Riley. _Wilson Co._: 3 miles east of Buffalo; 7 miles northeast of Fall River; 2 miles northwest of Neodesha. #Tantilla nigriceps nigriceps# Kennicott, Great Plains Black-headed Snake.--_Rooks Co._: 5 miles northwest of Stockton (No. 416); Stockton (No. 417). This is the northernmost known record for the species. #Agkistrodon mokeson mokeson# (Daudin), Southern Copperhead.--_Atchison Co._: Atchison (Nos. 201, 202, 573, 578)*; 5 miles north of Atchison (No. 653).* _Bourbon Co._: 6 miles northwest of Fort Scott (No. 294).* _Cherokee Co._: 1 mile north and 4 miles east of Crestline (Nos. 165-170)*; 2 miles east of Riverton (No. 293).* _Coffey Co._: 4 miles northeast of Burlington. _Franklin Co._: 2 miles southwest of Lane (Nos. 187-192, 194).* _Lyon Co._: 1.5 miles northwest of Reading (No. 7).* _Wabaunsee Co._: 2 miles northeast of Alma (No. 195).* _Woodson Co._: Lake Fegan (Nos. 627, 628, 630-632, 649).* #Sistrurus catenatus tergeminus# (Say), Western Massasauga.--_Chase Co._: 5 miles southwest of Saffordville (Nos. 8, 26, 112, 113, 295)*; 3 miles southwest of Elko (No. 145)*; 11 miles northeast of Matfield Green (No. 231)*; 8 miles south of Clements; 2 miles southwest of Elmdale (No. 333); 10 miles southwest of Olpe (No. 344).* _Lyon Co._: 10 miles south of Plymouth (Nos. 20, 121)*; 8 miles southwest of Emporia (No. 114)*; 5 miles northwest of Bushong (No. 353)*; 11 miles northeast of Emporia (No. 474). _Wabaunsee Co._: Kansas State Highway 99 just north of Lyon County (No. 641).* #Crotalus horridus horridus# (Linnaeus), Timber Rattlesnake.--_Atchison Co._: Atchison (Nos. 204-206)*; 5 miles north of Atchison (Nos. 642-652).* #Crotalus viridis viridis# (Rafinesque), Prairie Rattlesnake.--_Hodgeman Co._: Jetmore. #Sternotherus odoratus# (Latreille), Common Musk Turtle.--_Cherokee Co._: 1 mile north and 4 miles east of Crestline (No. 171). #Kinosternon flavescens flavescens# (Agassiz), Yellow Mud Turtle.--_Ford Co._: Rattlesnake Creek 2 miles south of Bucklin (1 spec.).* _Pratt Co._: 5 miles southeast of Pratt. _Sheridan Co._: Sheridan County State Park (No. 569). #Chelydra serpentina serpentina# (Linnaeus), Common Snapping Turtle.--_Chase Co._: 10 miles southwest of Olpe (No. 345); 3 miles east of Cottonwood Falls; 5 miles northeast of Strong City. _Greenwood Co._: (1 spec.).* _Lyon Co._: 1.5 miles northwest of Reading (No. 336); 5 miles south of Plymouth; 10 miles north of Emporia; Admire; 4 miles northwest of Olpe; Emporia. _Sheridan Co._: State Lake; 7 miles northeast of Quinter. #Terrapene ornata# (Agassiz), Ornate Box Turtle.--_Chase Co._: 14 miles southwest of Olpe; 6 miles south of Clements; 5 miles southwest of Saffordville. _Coffey Co._: 4 miles south of Gridley (No. 468)*; 1 mile west of Agricola (No. 638).* _Ellsworth Co._: 10 miles south of Ellsworth. _Greenwood Co._: (1 spec.).* _Hodgeman Co._: Jetmore. _Lyon Co._: 6 miles south of Plymouth; 8 miles southwest of Emporia; 7 miles west of Olpe. _Morris Co._: 5 miles northwest of Council Grove; 1 mile east of Skiddy; 5 miles south of Council Grove. _Rice Co._: Sterling. _Rooks Co._: Solomon River near Stockton (No. 408).* #Terrapene triunguis# (Agassiz), Carolina Box Turtle.--_Coffey Co._: 1 mile west of Agricola (No. 637).* #Chrysemys picta bellii# (Gray), Painted Turtle.--_Chase Co._: Kahola Creek, near Morris County line. _Dickinson Co._: 1.5 miles north of Herington. _Ford Co._: Rattlesnake Creek; 2 miles south of Bucklin (1 spec.).* _Lyon Co._: 3 miles north of Emporia; 6 miles south of Plymouth. _Ness Co._: 4 miles west and 1.5 miles north of Ness City (Nos. 613, 614).* _Sheridan Co._: Sheridan County State Park (No. 570). _Wilson Co._: 4 miles southeast of Buffalo. _Woodson Co._: Owl Creek north of Yates Center (1 spec.).* #Pseudemys floridana hoyi# (Agassiz), Toothed Turtle.--_Greenwood Co._: Holmer Creek south of Hamilton on Kansas State Highway 99 (Mus. Nat. Hist., Univ. Kans., No. 23148).* This is the second published locality for the species in Kansas; it has previously been reported from a locality 5.5 miles northeast of Coyville, Woodson County (Burt and Hoyle, Trans. Kans. Acad. Sci., 37:198, 1934). #Pseudemys scripta elegans# (Wied), Scribe Turtle.--_Chase Co._: 7 miles southwest of Saffordville. _Lyon Co._: 10 miles northwest of Emporia; 7 miles south of Plymouth. #Amyda mutica# (Le Sueur), Spineless Soft-shelled Turtle.--_McPherson Co._: Lindsborg. #Amyda spinifera spinifera# (Le Sueur), Spiny Soft-shelled Turtle.--_Chase Co._: 10 miles southwest of Olpe; 7 miles southwest of Saffordville (No. 351).* _Lyon Co._: 5 miles east of Emporia. _Ness Co._: 5.5 miles northwest of Ness. _Sheridan Co._: State Lake; 7 miles northeast of Quinter. 21-2762 
34949	----	Transcriber's Notes This Plain Text version has been prepared for Smooth Reading using the ASCII and Latin-1 character sets. Italic typeface has been represented using _underscores_; Bold typeface has been represented using =equals symbols=; Small caps typeface has been represented using UPPER CASE. Note that some unexpected spellings have not been changed from the original: Page 155 onwards: "parotoid" appears for "parotid". Page 172 (two references by Mori): "Quelpaert" appears for "Quelpart". The following changes to the text have been made: Page 159: changed "planyci" to "plancyi" (The most trenchant characters of _plancyi_ seem to be ...) Page 169: changed "juvenal" to "juvenile" (... does not conform to the juvenile pattern of either subspecies.) * * * * * UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 15, No. 2, pp. 149-173 January 31, 1962 Some Reptiles and Amphibians from Korea BY ROBERT G. WEBB, J. KNOX JONES, JR., AND GEORGE W. BYERS UNIVERSITY OF KANSAS LAWRENCE 1962 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 15, No. 2, pp. 149-173 Published January 31, 1962 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY JEAN M. NEIBARGER, STATE PRINTER TOPEKA, KANSAS 1962 28-8517 Some Reptiles and Amphibians from Korea BY ROBERT G. WEBB, J. KNOX JONES, JR., AND GEORGE W. BYERS In 1954, two of us (Jones and Byers) collected reptiles and amphibians in Korea incidental to field studies relating to hemorrhagic fever. The 382 specimens thus obtained were deposited either in the Museum of Natural History of The University of Kansas (KU), or in the Museum of Zoology of the University of Michigan (UMMZ), and are the basis for the present report. Continuous American military operations of one sort or another in Korea since 1945 have afforded opportunities for interested persons to obtain there collections of amphibians and reptiles, the study of which has resulted in several recent publications (Babb, 1955; Dixon, 1956; Hahn, 1959 and 1960; Shannon, 1956 and 1957; Stewart, 1953 and 1954; Tanner, 1953; Walley, 1958_a_ and 1958_b_). This paper, which contains comments on the natural history and taxonomy of 22 species, all previously reported from Korea, supplements earlier studies, especially Shannon's (1956) annotated list of the herpetofauna of the country. Shannon (_loc. cit._) recorded 36 kinds of reptiles and amphibians from Korea. Subsequently, _Bufo stejnegeri_ (previously omitted) was added by Shannon (1957), _Takydromus takydromoides oldi_ was described by Walley (1958_a_), and _Takydromus kwangakuensis_ was relegated to synonymy under _T. amurensis_ by Walley (1958_b_). Presently, then, 37 kinds are on record from the Korean Peninsula. In the accounts beyond, Jones and Byers are mostly responsible for the remarks on natural history, whereas Webb is mostly responsible for the taxonomic comments. The synonymies include (1) the original description, which is followed by (2) the first use of the name-combination here employed if it differs from the name as originally proposed, and (3) any synonyms having type localities in Korea. All measurements are in millimeters and all dates refer to the year 1954 unless otherwise indicated. A gazetteer of localities mentioned in the text and a list of literature cited follow the accounts of species. We are grateful to the officers, enlisted men and civilians associated in 1954 with the Field Unit of the Commission on Hemorrhagic Fever, Armed Forces Epidemiological Board, who aided our efforts in Korea; we are especially mindful of the contributions of Dr. Albert A. Barber, Dr. Marshall Hertig, Mr. Louis J. Lipovsky and Dr. Warren D. Thomas. We are grateful also to Mr. Yoshinori Imaizumi, National Science Museum of Japan, for his translations of several papers in Japanese, and to Dr. Edward H. Taylor for making certain pertinent references available to us. =Hynobius leechii= Boulenger _Hynobius Leechii_ Boulenger, Ann. Mag. Nat. Hist., ser. 5, 19:67, January, 1887 (type locality, Gensan [=Wonsan], Korea). _Hynobius leechii quelpaertensis_ Mori, Jour. Chosen Nat. Hist. Soc., 6:47 (Japanese) and 53 (English), March 25, 1928 (type locality, Quelpart Island [=Cheju Do], Korea). _Specimens examined_ (3).--1 mi. SW Inje, 1 (KU); 4 mi. NNE Sogwi-ri, Cheju Do, 2 (KU). _Description_ (KU 38774 from 1 mi. SW Inje).--Total length, 86 (head 13, body 40, tail 33); costal grooves (including axillary and inguinal), 13; two costal grooves between adpressed toes; length of inner branch of series of vomerine teeth less than distance between outer border of naris and peak of opposite series (tooth-rows V-shaped, approximately as long as broad); dorsal surface yellowish brown or buff (yellowish in life), having numerous blackish marks; venter yellowish cream, having an indistinct grayish mottling. _Remarks._--The salamander described above was found in a foxhole with another desiccated individual (not saved) on a military compound on April 24. The only other occurrence of _H. leechii_ on the mainland to come to our attention was the report of several larvae that were seen in a small pool on a hillside near Chip´o-ri in the summer of 1953. Each of the two specimens from Cheju Do (KU 38775-76) differs from KU 38774 in having (1) the length of inner branch of the vomerine series slightly greater than the distance between outer border of naris and peak of opposite series (tooth-rows V-shaped, longer than broad), (2) a dorsal and ventral keel on the tail, (3) one costal groove (rather than two costal grooves) between adpressed toes, and (4) in being darker both dorsally and ventrally. The area of buff on the dorsal surface of each specimen is reduced by a fine, blackish mottling and stippling, and the venter of each is grayish. Respective total lengths of KU 38775 and 38776 are 84 (head 12, body 36, tail 36) and 89 (12, 35, 42), and the number of costal grooves 13 and 14. Although the two specimens are of approximately the same size, the tail of KU 38776 is noticeably the longer; the tail of KU 38775 is thicker and deeper than that of KU 38776. The two specimens from 4 mi. NNE Sogwi-ri were taken on September 9 in damp substrate under volcanic rocks along a little-used road; although many rocks were overturned, only these two individuals were found. A South Korean soldier informed us that salamanders were fairly common on Cheju Do. Mori (1928_a_:16) first mentioned in Japanese text the alleged distinctiveness of the salamander occurring on Cheju Do. Later, Mori (1928_b_:47 in Japanese, and 1928_c_:53 in English) provided valid descriptions of the subspecies, _Hynobius leechii quelpaertensis_. Okada (1934:17) questioned the validity of _H. l. quelpaertensis_ and Sato (1943) regarded the salamanders of Cheju Do as inseparable from the Korean _H. leechii_. The English description of _quelpaertensis_ is briefer than the preceding one in Japanese and lacks comparisons with related forms. KU 38775-76 seemingly differ appreciably from the description of _quelpaertensis_ only in having the series of vomerine teeth narrowly V-shaped and longer than broad. We tentatively follow Sato in regarding _quelpaertensis_ as a synonym of _leechii_. =Bombina orientalis= (Boulenger) _Bombinator orientalis_ Boulenger, Ann. Mag. Nat. Hist., ser. 6, 5:143, pl. IX, fig. 2, February, 1890 (type locality restricted to Chefoo, China, by Pope, Bull. Amer. Mus. Nat. Hist., 61:435, August 29, 1931). _Bombina orientalis_, Stejneger, Bull. U. S. Nat. Mus., 58:51, figs. 30-43, pl. VII (reproduction from Boulenger, _supra_), July 22, 1907. _Specimens examined_ (87).--2 mi. N Chip´o-ri, 8 (KU), 5 (UMMZ); 1 mi. SW Inje, 1 (KU); 15 mi. NE Mosulp´o, Cheju Do, 6 (KU); Sangdaehwa, 2 (KU); Taehoesan-ni, 1 (KU); 1 mi. W Tangjonggok, 32 (KU), 17 (UMMZ); Tangnim-ni, 2 (KU); 3 mi. SW Yanggu, 1 (KU); 2 mi. N Yongdae-ri, 8 (KU), 4 (UMMZ). _Remarks._--Most of our specimens were taken from breeding congresses after heavy rains in rice fields and other shallow temporary waters. Thirteen individuals from Chip´o-ri were collected from foxholes around the edge of a military compound (two pairs in amplexus; no egg masses seen), and represent a small sample of frogs that were everywhere following a heavy rain on the night of May 13-14. On April 23, 32 _Bombina orientalis_ and three _Rana temporaria dybowskii_ were trapped in the water-filled bottom of an unused grease pit near Tangjonggok. Many tadpoles and two kinds of egg masses (small clusters and beadlike strings) were present; the small clusters of _Bombina_ were commonest. On June 13 at the same locality, thousands of these toads were observed (hundreds in axillary amplexus) in foxholes, temporary rain pools, and backwashes along the Puk-ch´on [river]. On June 12 near Yongdae-ri many individuals were seen (several pairs in amplexus), along Route 24 paralleling the Puk-ch´on, in rain pools and in ditches and backwashes from the river; almost all available water contained small (approximately 10 × 10 mm.) egg masses. Numbers of eggs per mass, selected at random, were 5, 2, 2, 5, 2, 8, 8, 2 and 5. Some that were saved subsequently hatched on June 15-17. The call is a quiet low trill or series of staccato whistles rising slightly at the beginning; a short peeplike note also was heard. The specimens from Cheju Do, which are generally smaller than those collected on the mainland in spring, were taken on September 6 in a small stream that had large volcanic rocks in many places and that was flanked by thick brush and small trees. The earliest and latest dates on which _B. orientalis_ was collected were April 21 and September 6, respectively. In the breeding season, males are distinguished from females by the large blackish (probably brownish earlier in season) areas on the anteroventral surface of the antebrachium, the metacarpal tubercle, and the inner surface of the first finger (sometimes also the second and third). Also, males have conspicuous black-tipped tubercles on the back (usually absent in females) that extend onto the limbs (usually smooth in females, at least laterally). Field observations by one of us (Byers) suggested that the dorsal pattern of males had greater contrast than that of females and that the venter was brighter reddish. Eight females from Tangjonggok averaged 47.9 (43-51) in snout-vent length, whereas 24 males from there averaged 50.0 (46-55), indicating little, if any, size difference between the sexes. Okada (1931:29) recorded variation in color of live Korean individuals (green or brown dorsally and pale yellow or red ventrally) and variation in extent of black markings on the belly (_op. cit._:fig. 12). The specimens from Cheju Do (28, 32, 32, 32, 37 and 46 in snout-vent length) have less black ventrally than specimens from the mainland. =Bufo bufo gargarizans= Cantor _Bufo gargarizans_ Cantor, Ann. Mag. Nat. Hist., ser. 1, 9:483, August, 1842 (type locality, island of Chusan, China). _Bufo bufo gargarizans_, Stejneger, Bull. U. S. Nat. Mus., 58:59, July 22, 1907. _Specimens examined_ (10).--Central National Forest, near Pup´yong-ni, 1 (KU); 5 mi. NW Choksong, near Imjin River, 1 (KU); 5 mi. E Seoul, 1 (KU); 6 mi. E Seoul, 4 (KU), 2 (UMMZ); 1 mi. S Yami-ri, 1 (KU). _Description (nine females)._--Dorsal surface brownish, having indistinct pale areas, some of which tend to form longitudinal stripes that extend posteriorly from parotoid glands; blackish mark, usually on lateral part of parotoid, having short spurs directed posteriorly and ventrally; edge of upper jaw and warts on dorsal surface becoming blackish with increasing size; small, conspicuous group of warts near angle of jaw below parotoid; middorsal warts tending, at level of posterior edge of parotoids, to form a V that has its apex between the parotoids; ventral surface pale yellowish, sometimes having well-defined blackish marks; granular underparts of large specimens having small blackish tubercles. _Male (KU 40118 from 5 mi. E Seoul)._--Snout-vent length, 65; no vocal sacs or slits; dorsal and inner surfaces of first and second fingers, and inner surface of third finger black; canthus rostralis indistinct (a well-defined ridge on right side); nostrils closer to tip of snout than to eye, their distance from each other slightly less than interorbital width; interorbital width (6.2) greater than width of eyelid (4.7); tympanum distinct, circular, its diameter (3.0) less than length of eye (6.5), and approximately twice distance (1.6) of tympanum from eye; no cranial crests; parotoid gland elongate, approximately twice as long as broad (12.5 × 5.0), narrowly separated from posterior edge of eyelid; head elongate (width at posterior edge of tympanum, 23.6); length from posterior edge of tympanum to tip of upper jaw, 18.9; first finger slightly longer than second, fourth finger about two-thirds as long as third; most subarticular tubercles divided; outer palmar tubercle larger than inner; heels not touching when folded legs placed at right angles to longitudinal axis of body; tibiotarsal articulation just reaching eye when leg laid forward; tarsometatarsal articulation not reaching beyond snout; foot large (tibiotarsal articulation to tip of fourth toe approximately 46.0); fourth toe approximately half webbed, other toes more than half webbed; edges of webs somewhat crenulate; some subarticular tubercles divided; length of inner metatarsal tubercle (4.5) more than half length of first toe (7.0); inner metatarsal tubercle larger than outer, both darkened; tarsal fold extending from inner metatarsal tubercle for approximately two-thirds length of tarsus; tips of toes (not fingers) darkened; dorsal surface of back and proximal part of hind legs coarsely granular, of rounded, pavement-type tubercles lacking sharp tips; small group of warts near angle of jaw below parotoids; dorsal pattern contrasting and irregular (especially on limbs), of dark brown and pale gray; conspicuous black mark (interrupted) on lateral surface of parotoid having two, well-defined spurs that project posteroventrally; undersurface granular, lacking markings except for two indistinctly-margined dark spots on chest, and black spot on left leg. _Remarks._--This nocturnal, introduced species (Okada, 1931:47) is presumably widespread in Korea and seemingly prefers lowland habitats. Individuals were taken in sparse vegetation on a sand flat near the Han River, at the edge of a rice field in a light rain, along a road at night, and in millet fields adjacent to the Han River, which was flooding at that time (July 9). As is obvious from the foregoing descriptions, the male (KU 40118), which was obtained on March 19, differs considerably from the nine females; neither does it agree with Stejneger's (1907:66) or Okada's (_op. cit._:45-46, fig. 18) description of males of _Bufo bufo asiaticus [=gargarizans]_ from Wonsan and Seoul. Upon cursory examination, KU 40118 is notable for having a contrasting dorsal pattern and elongate, ranidlike proportions. Some of the characteristics resemble those of _Bufo raddei_ Strauch as given by Stejneger (_op. cit._:70-72, figs. 53-57), Okada (1935:9, figs. 2 and 32-34, pls. II-III), and Liu (1950:203-205, fig. 43). Stejneger (_op. cit._:59-68) recognized _B. b. gargarizans_ as occurring in southern China, and _Bufo bufo asiaticus_ as the subspecies occurring in northern China. Subsequently, _asiaticus_ was relegated to synonymy under the earlier-named _gargarizans_--see discussions by Pope and Boring (1940:33) and Liu (_op. cit._:220). =Kaloula borealis= (Barbour) _Cacopoides borealis_ Barbour, Bull. Mus. Comp. Zool., 51(12):231, April, 1908 (type locality, Antung, Manchuria). _Kaloula borealis_, Noble, Amer. Mus. Novit., 165:6, April 16, 1925. _Specimens examined_ (8).--5 mi. ESE Seoul, 1 (KU); 6 mi. E Seoul, 3 (UMMZ); 7 mi. ESE Seoul, 4 (KU). _Remarks._--On April 5, one male and three females were uncovered by a bulldozer from between one and two feet below the surface of the ground in an old Korean burial mound; one individual was completely surrounded by compact soil. All quickly became active when placed in water. Two of the females (43 and 44 in snout-vent length) contained masses of immature eggs. A male obtained on June 4 was found during a rain; the three UMMZ specimens were obtained on July 8 on banks above the Han River. Breeding of this species seems to coincide with the rainy season in late spring and early summer when males were noted calling around flooded ditches and swales in deep grass. The local Korean name of the species, which sounds something like "maeng-kongi," is said to come from the call, which is best described as a monotonous, snoring sound that rarely is heard in two parts as suggested by the name. =Hyla arborea japonica= Günther [_Hyla arborea_] Var. _japonica_ Günther, Catalogue of the Batrachia Salientia in the ... British Museum, p. 109, 1858 (type locality, Japan). _Hyla arborea_ var. _savignyi_ Boulenger, Ann. Mag. Nat. Hist., ser. 5, 19:67, January, 1887 (type locality, Gensan [= Wonsan], Korea). _Hyla stepheni_ Boulenger, Proc. Zool. Soc. London, p. 579, pl. 51, fig. 1 (for 1887), April, 1888 (type locality, Port Hamilton, a small island between Korea and Japan). _Specimens examined_ (44).--Central National Forest, near Pup´yong-ni, 2 (KU); 3 mi. NW Chip´o-ri, 1 (KU); 1 mi. N Mosulp´o, Cheju Do, 1 (KU); 1 mi. NW Oho-ri, 13 (KU), 3 (UMMZ); Sangbonch´on-ni, 2 (UMMZ); 5 mi. ESE Seoul, 8 (KU); 6 mi. E Seoul, 10 (KU), 3 (UMMZ); 7 mi. NNE Sogwi-ri, Cheju Do, 1 (UMMZ). _Remarks._--Hylids from 5 mi. ESE Seoul were collected from a cement-walled pit at the Seoul City Water Works; a specimen of _Elaphe rufodorsata_ taken in the pit had eaten one hylid. Two individuals were taken in the morning of May 29 on leaf litter in a wooded valley in the Central National Forest where a number were calling in a light rain, but the species was rarely found in woods. Two frogs were found along a rocky stream at Sangbonch´on-ni. Most individuals were taken while calling, on grasses and reeds or on the ground, along the edges of rice fields. Sixteen hylids collected 1 mi. NW Oho-ri were calling in shallow water of a rice field on a hillside, but none was heard in a large lake nearby or in adjacent fields. On May 15, 4 mi. ESE Ch´orwon, approximately one hundred tadpoles, thought to be of this species, congregated near a drain (into a lower field) of an unused rice field; the tadpoles were well-developed, some having hind legs. The earliest and latest dates of collection represented in our material are May 8 and October 29. The call is best described as a raspy "waak," "week," or "wiick" in the middle register. The listing of "Hylae arboreae var japonicae descript pars _Schleg. in Fauna Japon._ p. 112 ..." by Günther (1858:81) in synonymy under the account of _Polypedates schlegelii_, implies that Schlegel was the first author to use the name-combination _Hyla arborea japonica_. Boulenger (1882:86, 381) went so far as to credit Schlegel as the author of the name _japonica_. The reason for this action is not known because Schlegel (in von Siebold, 1838:112) referred to this hylid only under the name "Hyla arborea." =Rana rugosa= Schlegel _Rana rugosa_ Schlegel, Reptilia [Saurii et Batrachii], _in_ von Siebold, Fauna Japonica, p. 110, pl. 3, figs. 3-4, 1838 (type locality designated as Japan, probably near Nagasaki, by Stejneger, Bull. U. S. Nat. Mus., 58:123, July 22, 1907). _Specimens examined_ (26).--Central National Forest, near Pup´yong-ni, 13 (KU), 1 (UMMZ); 2 mi. S Ch´orwon, 4 (KU); 2 mi. E Hoengsong, 3 (KU); 1 mi. NW Oho-ri, 1 (KU); 5 mi. ESE Seoul, 1 (KU); 6 mi. E Seoul, 3 (UMMZ). _Remarks._--_Rana rugosa_ was associated with _Rana nigromaculata_ and _Rana amurensis coreana_ at all localities where the species was taken save at 2 mi. E Hoengsong, where _R. a. coreana_ was not observed. Three specimens of _R. rugosa_ were collected among grasses and reeds in water along the edge of Ch´orwon Reservoir, 2 mi. S Ch´orwon, where they were difficult to find in the thick vegetation even though their low, soft calls were heard; the specimen from 1 mi. NW Oho-ri was found in a rice field. Otherwise, habitats recorded indicate a preference for small, fast-flowing streams, especially in wooded valleys. On one occasion, individuals were found trapped in cement-walled pits about old ruins on a wooded hillside in the Central National Forest. The earliest and latest dates of capture among our specimens are May 15 and November 6. In addition to the localities listed above, the species was observed 4 mi. W Ch´ungju. _R. rugosa_ may have an extensive breeding season as suggested by the variation in size of frogs collected or observed in 1954. Of nine frogs obtained on May 29, five ranged in snout-vent length from 26 to 28, and four from 42 to 54. Three specimens collected on October 9 measured 39, 41, and 55, and two obtained on November 6 measured 25 and 37. =Rana nigromaculata= Hallowell _Rana nigromaculata_ Hallowell, Proc. Acad. Nat. Sci. Philadelphia, [12]:500 (for 1860), 1861 (type locality, Simoda, Japan). _Specimens examined_ (47).--Central National Forest, near Pup´yong-ni, 6 (KU); 2 mi. S Ch´orwon, 5 (KU); 4 mi. W Ch´ungju, 2 (KU); 7 mi. W Ch´ungju, 1 (KU); 2 mi. E Hoengsong, 1 (KU); 8 mi. SW Kunsan, 1 (KU); 1 mi. NW Oho-ri, 5 (KU); 5 mi. ENE Pusan, 2 (KU); 5 mi. ESE Seoul, 9 (KU); 6 mi. E Seoul, 3 (KU), 10 (UMMZ); 6 mi. NNE Sogwi-ri, Cheju Do, 2 (KU). _Description._--Back brownish or grayish (greenish in life), having few, indistinct or well-defined, dark blotches, or extensive blackish areas (representing fusion of markings); pale, middorsal stripe (pale green, buff or yellowish in life) from snout to anus, sometimes as wide as interorbital width, but indistinct or lacking when pattern on back absent; blackish bar often present behind tympanum; posterior surface of thigh mottled; underparts pale yellow to whitish, sometimes having a few dusky marks on throat; longitudinal ridges between dorsolateral folds indistinct in some small frogs; largest female and male having respective snout-vent lengths of 100 and 70. _Remarks._--_Rana nigromaculata_ is the most abundant ranid in central Korea and, in a general way, the ecological equivalent of _Rana pipiens_ in temperate North America. The species is associated with most aquatic habitats, from rocky streams to rice fields and large impoundments. In the vicinity of Seoul the din of large breeding congresses was heard more or less continuously from mid-April to mid-May. Large numbers of juveniles (approximately one inch long) were noticed first on July 8 and were present thereafter for about three weeks, being commonest in standing water after heavy rains or during prolonged showers. These data and the different sizes of individuals collected at the same time suggest either variable growth or, more probably, an extensive breeding season. Our earliest and latest dates of collection are April 16 and October 7. The Korean name for "frog," most often applied to _R. nigromaculata_, sounds something like "keg-oh-ree." The call is a prolonged, raspy, staccato croak, sometimes with a rising inflection at the end. In addition to the localities listed above, the species was observed 5 mi. W Kwangju and 3 mi. S Osan. Despite a high degree of individual variation, _Rana nigromaculata_ seemingly varies geographically as well; some subspecies probably should be recognized, but the species as a whole has never been thoroughly studied systematically. The division of _R. nigromaculata_ into three subspecies by Schmidt (1927:563-567) was considered untenable by Fang and Chang (1931:95-98), and it has been regarded by most recent authors as a variable, monotypic species. The named subspecies _R. n. chosenica_ (Okada, 1931:89, with type locality at Seoul, and geographically restricted to Korea) was considered a subspecies of _Rana plancyi_ by Shannon (1956:36). The most trenchant characters of _plancyi_ seem to be the wide dorsolateral folds, the uniform greenish dorsum, the presence of dermal pustules on the back between the dorsolateral folds, and the lack of a mottled pattern on the posterior surface of the thigh. Among our specimens of _R. nigromaculata_, the width of the dorsolateral folds is variable, a uniform greenish dorsum is found only in large males, dermal pustules are mixed with ridges in only one male (KU 38733), and all have a spotted or mottled pattern on the posterior surface of the thigh. All of our specimens having an indistinct pattern on the back, or lacking a pattern, are males and resemble the photographs of males published by Moriya (1954: pl. I, fig. 5) and Liu (1936: pl. IV, figs. 1-2); juveniles of both sexes and large females have contrasting patterns. None of our frogs seems, therefore, clearly referable to the species _plancyi_, although some characters are suggestive of _plancyi_. Moriya (_op. cit.:19_), who studied variation of _R. nigromaculata_ in Japan, noted that one of the most distinct populations there (_R. n. brevipoda_) resembled _Rana plancyi_. Ting (1939) discovered that _nigromaculata_ and _plancyi_ were cross-fertile and raised hybrid larvae through metamorphosis. Pope and Boring (1940) suggested hybridization between the two species in eastern China, and the above mentioned facts suggest to us the possibility of hybridization in other regions. =Rana amurensis coreana= Okada _Rana temporaria coreana_ Okada, Annot. Zool. Japon., 11:140 (footnote), July 25, 1927, _nomen nudum_. _Rana temporaria coreana_ Okada, Jour. Chosen Nat. Hist. Soc, 6:19, pl. 1, fig. 7, 1928 (type locality, Keijo [= Seoul], Korea). _Rana amurensis coreana_, Shannon, Herpetologica, 12:38, March 6, 1956. _Specimens examined_ (9).--Central National Forest, near Pup´yong-ni, 1 (KU); 2 mi. S Ch´orwon, 1 (KU); 4 mi. W Ch´ungju, 1 (KU); 1 mi. N Oho-ri, 1 (KU); 5 mi. ESE Seoul, 3 (KU); Yongp´yong, 2 (KU). _Remarks._--One individual of _R. a. coreana_ (KU 38698) and one of _Rana temporaria dybowskii_ (KU 38715) were collected on May 29 along a stream in the Central National Forest in association with _R. rugosa_ and _R. nigromaculata_. Specimens of _coreana_ from the vicinity of Seoul were found in rice fields. The earliest date of collection was April 13 at Yongp´yong. Our largest specimen of _coreana_ measured 47 in snout-vent length. Because _R. a. coreana_ and _Rana temporaria dybowskii_ are sympatric in central Korea and closely resemble one another, the two species were not distinguished in the field and the following observations may pertain to either (or both) species. Wood frogs were observed 2 mi. E Songdong-ni on July 12 in paddies (rice fields) along with individuals of _Hyla arborea_, _Rana rugosa_, and _Rana nigromaculata_. At Chip´o-ri on April 6, individuals (probably _R. t. dybowskii_) were seen in a seepage pool from an abandoned rice field; _R. nigromaculata_ also was seen there. Six or seven egg masses (some having small tadpoles) were observed in the shallow water, but it was not certain to which species the eggs belonged. Completely metamorphosed young (probably _R. a. coreana_) were first seen 1 mi. N Oho-ri on June 9. At Taehoesan-ni on November 12, several sluggish frogs were seen in a small pool that was covered by a thin layer of ice. On September 26 in the Central National Forest, many wood frogs of various sizes were observed. _R. amurensis_ and _R. temporaria_ probably have extended breeding seasons that correspond to those of _R. rugosa_ and _R. nigromaculata_. Judging from our observations, _amurensis_ prefers the proximity of water, whereas _temporaria_ may occur some distance from permanent water. In our specimens, _R. amurensis coreana_ differs from _R. temporaria dybowskii_ in having (1) smaller maximal size, (2) more slender body, (3) shorter legs, (4) incompletely webbed toes, (5) no mottling or barring on lips, (6) no contrasting barred pattern on hind legs, (7) dark brown stripes (usually) between dorsolateral folds, (8) a dark brown, linear mark below canthus, and (9) an immaculate ventral surface. Two additional distinguishing characters, which we found difficult to evaluate, are the nearly straight, dorsolateral folds, and lack of vocal sacs or ostia in males of _R. a. coreana_ (Shannon, 1956:38). Some of the differences between the two species were illustrated by Okada, 1931:107, fig. 48, _R. temporaria temporaria_ [=_R. t. dybowskii_] and 123, fig. 54, _R. temporaria coreana_ [=_R. amurensis coreana_]. =Rana temporaria dybowskii= Günther _Rana Dybowskii_ Günther, Ann. Mag. Nat. Hist., ser. 4, 17:387, May, 1876 (type locality, Abrek Bay, near Vladivostok, Siberia). _Rana temporaria dybowski_, Shannon, Herpetologica, 12:38, March 6, 1956. _Specimens examined_ (20).--Central National Forest, near Pup´yong-ni, 7 (KU); Chip´o-ri, 2 (KU); 1 mi. SW Inje, 6 (KU); 8 mi. SW Kangnung, 1 (KU); Taegwang-ni, 1 (KU); 1 mi. SW Tangjonggok, 3 (KU). _Remarks._--On October 9 in the Central National Forest, five individuals were found in a concrete-walled pit in old ruins on a wooded hillside; no specimens of _Rana amurensis coreana_ were taken there. _R. t. dybowskii_ was most often taken on high, moist slopes, and seemed to be especially common in forests. The specimen from 8 mi. SW Kangnung was obtained in a wooded area along a mountain stream. The earliest date of collection of a specimen of _dybowskii_ was March 7 at Taegwang-ni. See also the remarks under the preceding account of _Rana amurensis coreana_. The largest male among our specimens measured 65 in snout-vent length and the largest female, 79. Five gravid females had snout-vent lengths of 64, 68, 69, 69 and 70. =Trionyx sinensis= Wiegmann _Trionyx (Aspidonectes) sinensis_ Wiegmann, Nova Acta Acad. Leopold.-Carol., 17:189, 1835 (type locality, near Macao, China). _Specimen examined._--Han River, 5 mi. ESE Seoul, 1 (KU). _Remarks._--Our only specimen was purchased from a man who had captured it by hand in the Han River; it was the only turtle seen during our stay in Korea. Koreans eat turtles, and the elaborate (and relatively permanent) fish-traps that they construct across streams and small rivers probably reduce the size of populations of _T. sinensis_ and other species. =Eremias argus= Peters _Eremias argus_ Peters, Monatsber. preuss. Akad. Wiss., Berlin, p. 61, fig. 3 (for 1869), 1870 (type locality, Chefoo, China). _Specimens examined_ (23).--Chip´o-ri, 1 (KU); 5 mi. E Seoul, 3 (KU), 3 (UMMZ); 5 mi. ESE Seoul, 4 (KU); 6 mi. E Seoul, 10 (UMMZ); 7 mi. ESE Seoul, 2 (KU). _Remarks._--Individuals of _E. argus_ were most often seen on dry hillsides having a relatively sparse cover of vegetation. The first lizard of this species was taken on April 2. In 1954 the last part of March and early part of April were generally warm, with temperatures above 70° F. on several occasions; probably some _E. argus_ were active in late March. KU 38773 (snout-vent length, 51) laid three eggs between June 4 and 14; KU 38768 (snout-vent length, 58) obtained on May 8 was gravid, containing four eggs. Testes of lizards in the breeding season measure approximately 4.0 x 2.5 (KU 38772, obtained on June 16). The snout-vent length of our largest female is 61, that of the largest male, 57. The snout-vent length of 11 specimens averaged 77 (67-96) per cent of length of tail. =Tachydromus amurensis= Peters _Tachydromus amurensis_ Peters, Sitzungsber. Gesell. naturf. Freunde Berlin, p. 71, 1881 (type locality, Kossakewitcha, Amurland). _Specimens examined_ (3).--Central National Forest, near Pup´yong-ni, 1 (KU), 1 (UMMZ); Majon-ni, 1 (KU). _Remarks._--One of our specimens was found among grasses along a small stream in the Central National Forest. The other two were obtained by other persons and we lack knowledge of conditions of their capture. A juvenile (KU 39416, snout-vent length, 25) that was obtained on September 9 is tentatively referred to this species. There seem to be three femoral pores on the left leg but the number is indistinct on the right. The specimen is dark and lacks a pattern. Its condition precludes counts of ventral scales (not keeled), but scalation is otherwise the same as a male (KU 40120, snout-vent length approximately 47, length of tail, 124). The third specimen, a male (UMMZ 113442, snout-vent length, 51, length of tail, 115), agrees with KU 40120, except in having 32 instead of 29 dorsal scales at midbody, 4-4 instead of 3-3 femoral pores, and in lacking a pale stripe from eye through ear to shoulder. =Tachydromus wolteri= Fischer _Tachydromus Wolteri_ Fischer, Jahrb. Wiss. Anst. Hamburg, 2:82 (for 1884), 1885 (type locality, Chemulp´o, Korea). _Specimens examined_ (2).--Yongp´yong, 2 (KU). _Remarks._--On April 14, two females (57 and 45 in snout-vent length, the tail of the latter measuring 103) were easily captured by hand on a burned-over rice field. =Lygosoma reevesii= (Gray) _Tiliqua Reevesii_ Gray, Ann. [Mag.] Nat. Hist., ser. 1, 2:292, December, 1838 (type locality, China). [_Lygosoma (Liolepisma) laterale_] var. _reevesi_, Boettger, Katalog der Batrachier-Sammlung ..., p. 104, 1893. _Specimens examined_ (6).--Central National Forest, near Pup´yong-ni, 3 (KU); 4 mi. NNE Sogwi-ri, Cheju Do, 1 (KU); 7 mi. NNE Sogwi-ri, Cheju Do, 1 (UMMZ); 16 mi. NE Mosulp´o, Cheju Do, 1 (UMMZ). _Remarks._--On October 23 an individual was captured while sunning on a stump on a wooded hillside in the Central National Forest; two others at this locality were collected on damp ground-cover on the same hillside. A juvenile from Cheju Do was found among moss-covered rocks in a stream bed; the other specimens from Cheju Do were found among moss-covered rocks on the western slope of Halla San. Each ovary of a female obtained on October 23 contained five enlarged follicles, about 1 mm. in diameter. The left testis of a male obtained on August 10 seemed enlarged, indicating possible sexual activity, and measured approximately 6 x 2 mm. The snout-vent length of our largest male is 41, that of our largest female, 48. The prefrontals are in contact in all of our specimens save one (UMMZ 113446). There is disagreement among herpetologists concerning the generic name of the small lygosome skink in the United States and its ecological equivalent in China and Korea. We tentatively use _Lygosoma_ (Conant, 1951:207-208), although Mittleman (1950) pointed out reasons for using _Scincella_. Shannon (1956:41) discussed the debated issue whether or not the lygosome skinks of the New and Old worlds are conspecific. =Rhabdophis tigrina lateralis= (Berthold) _Tropidonotus lateralis_ Berthold, Nachrichten Gesell. Wiss. Göttingen, p. 180, 1859 (type locality, China). _Specimens examined_ (26).--Central National Forest, near Pup´yong-ni, 1 (KU); 2 mi. N Chip´o-ri, 2 (KU); 3 mi. NW Chip´o-ri, 4 (KU); 4 mi. N Ch´onan, 1 (KU); 3 mi. S Kumhwa, 1 (KU); 1 mi. SW Naegong-ni, 1 (KU); 4 mi. E Seoul, 1 (KU); 5 mi. E Seoul, 2 (UMMZ); 5 mi. ESE Seoul, 4 (KU); 6 mi. E Seoul, 1 (KU), 4 (UMMZ); 7 mi. ESE Seoul, 1 (KU); 6 mi. NNE Sogwi-ri, Cheju Do, 2 (KU); 5 mi. NE Taejon, 1 (KU). _Remarks._--This common, vagrant species was found on brushy hillsides, near buildings on hills above rice fields, in tall grasses near streams, in rice fields, and along drainage and irrigation ditches. The earliest and latest dates of collection were April 5 and November 7. On the first date mentioned an individual was found in hibernation with five _Elaphe rufodorsata_ and one _Agkistrodon halys_ in an earthen Korean burial mound. The specimen was uncovered by a bulldozer at a depth of about one foot below the surface. We were told that 18 snakes of this species were found in the same place (7 mi. ESE Seoul) the previous winter. The stomach of each of four individuals contained one _Rana nigromaculata_. The stomach of another individual contained a _R. nigromaculata_ and remains of a carabid beetle, whereas another contained three small, partially-digested frogs that appeared to be _Hyla arborea_. P. M. Youngman reported to us that he found a snake of this species that was attempting to swallow a toad, _Bufo bufo gargarizans_. One of the small individuals from Cheju Do was being eaten by a _Zamenis spinalis_ when found. One specimen was parasitized by three nematodes, _Kalicephalus natricis_ (see Olsen, 1957:208). Two females of this oviparous species (lengths of body, 680 and 700) collected on May 14 contained nine eggs (18 mm. long), and 13 eggs (15 mm.) respectively; a third (length of body, 610) obtained on June 26 contained 10 eggs that were approximately 18 mm. long. A female (UMMZ 113458, length of body, 710), which was captured on July 10 and kept alive in captivity, laid 11 eggs on August 12 between 9 and 10 in the morning. The weight of nine of these eggs averaged 3.32 (3.0-3.6) grams; the last two eggs deposited were small and weighed only 1.3 and 1.4 grams. The eggs were incubated unsuccessfully. One that was opened on September 14 and another opened on September 26 contained young easily recognized as of this species. In captivity the parent snake underwent ecdysis on about July 20 and again on August 26. Our largest female and largest male have respective total lengths of 1013 (840 + 173) and 740 (575 + 165). Our smallest specimens, captured on September 9, measured 215 and 230 mm. in length of body, and probably represent young of the year. The snake found in hibernation on April 5 measured 275 in length of body. The ventrals of 11 males averaged 161.3 (158-171) and those of 14 females, 165.1 (160-170); subcaudals of eight males averaged 69.6 (66-74) and those of 14 females, 61.5 (52-73). Males seem to have small scales in the anal region that are more strongly keeled than scales elsewhere on the body (the scales catch on finger tips when rubbed in a posteroanterior direction), but males lack small tubercles on the upper and lateral parts of the head as mentioned by Maslin (1950:433). The comments of the same author (_op. cit._:434) concerning integumental poison glands in the nuchal region of this species are of interest in view of several reports that we received of swollen extremities resulting from handling snakes of this species. In using the generic names _Rhabdophis_ and _Amphiesma_ for species formerly placed in the genus _Natrix_, we follow Malnate (1960), who divided _Natrix (auct.)_ into five distinct genera. =Amphiesma vibakari ruthveni= (Van Denburgh) _Natrix vibakari ruthveni_ Van Denburgh, Proc. California Acad. Sci., ser. 4, 13(2):3, July 26, 1923 (type locality, Pusan, Korea). _Specimens examined_ (5).--Central National Forest, near Pup´yong-ni, 1 (KU); 4 mi. SW Ch´ongyang-ni, 1 (KU); 10 mi. NE Mosulp´o, Cheju Do, 1 (UMMZ); 6-7 mi. NNE Sogwi-ri, Cheju Do, 1 (KU), 1 (UMMZ). _Remarks._--The specimen from the Central National Forest was captured on August 18 near a stream on a damp ground-cover of leaves. The specimens from Cheju Do were taken in early September, one in a grassy area, and the other two on earthen banks of road-cuts on the slopes of Halla San. The stomach of one individual from Cheju Do contained an earthworm. Our largest specimen, a male having 154 ventrals and 68 subcaudals, measured 508 (380 + 128). The subcaudal counts of 68 (KU 38861) and 69 (UMMZ 113461) on two males from Cheju Do are higher than the maximal count known for the subspecies _ruthveni_ in Korea, and resemble those of _Amphiesma vibakari vibakari_ of the Japanese islands. The subcaudals average 61 (55-65) in _ruthveni_ and 71 (63-83) in _vibakari_ according to Van Denburgh (1923:3-4). A juvenile from the Central National Forest (KU 38862), lacking the tip of the tail, has 64 subcaudals. =Dinodon rufozonatum= (Cantor) _Lycodon rufo-zonatus_ Cantor, Ann. Mag. Nat. Hist., ser. 1, 9:483, August, 1842 (type locality, island of Chusan, China). _Dinodon rufozonatus_, Peters, Sitzungsber. Gesell. naturf. Freunde Berlin, p. 89, 1881. _Specimens examined_ (4).--Central National Forest, near Pup´yong-ni, 3 (KU); Yongsan (Seoul), 1 (UMMZ). _Remarks._--The three specimens from the Central National Forest were taken in the period August 12-26. Two were caught in live-traps set for small mammals in deep forest among granite outcrops. The specimen from Yongsan was obtained on October 27 in a partly wooded area. Ventrals and subcaudals of our four specimens (all males) numbered, respectively, 198, 200, 198, 205, and 74, 75, 75, __. Total length of the largest specimen was 960 (790 + 170). We follow Chang (1932:54) and most subsequent authors in regarding _D. rufozonatum_ as a monotypic species. =Zamenis spinalis= (Peters) _Masticophis spinalis_ Peters, Monatsber. preuss. Akad. Wiss., Berlin, p. 91 (for 1866), 1867 (type locality, unknown--"Mexico" erroneously listed). _Zamenis spinalis_, Günther, Ann. Mag. Nat. Hist., ser. 4, 9:22, January, 1872. _Specimens examined_ (2).--5 mi. ESE Seoul, 1 (KU); 6 mi. NNE Sogwi-ri, Cheju Do, 1 (KU). _Remarks._--The specimen from Cheju Do was captured on September 9 in tall grass near a small stream and was eating a small _Rhabdophis tigrina_. The female from near Seoul was obtained from a Korean on June 10, and was gravid (six eggs, each approximately 35 mm. in length). The length of body measured approximately 550 and the length of incomplete tail 168 in one specimen (KU 38777, female from 5 mi. ESE Seoul), 540 and 183 in the other (KU 38778, female from Cheju Do). Respective ventral and subcaudal counts of the two females are 204, 194, and 74+, 86. There is some disagreement in the literature as to the proper generic name of this snake. Differences in dentition between Old World species (referable to _Zamenis_) and the American species (referable to _Coluber_) are discussed by Bogert and Oliver (1945:365). The species _spinalis_ has been referred to _Coluber_ by several authors (see Pope, 1935:226). =Elaphe dione= (Pallas) _Coluber dione_ Pallas, Reise durch verschiedene Provinzen des Russischen Reichs, 2:717, 1773 (type locality, "Salt steppes toward the Caspian Sea" according to Stejneger, Bull. U. S. Nat. Mus., 58:315, July 22, 1907). _Elaphis dione_, Duméril and Bibron, Erpétologie générale ..., 7:248, 1854. _Specimens examined_ (10).--Choksong, 1 (KU); 4 mi. N Ch´onan, 1 (KU); Seoul, 1 (KU); 5 mi. E Seoul, 1 (KU), 2 (UMMZ); 5 mi. ESE Seoul, 1 (KU); 6 mi. E Seoul, 1 (UMMZ); Taegwang-ni, 1 (KU); 2 mi. WSW Tongjonggok, 1 (KU). _Remarks._--This species seemingly occurs in upland habitats. Specimens were taken on rocky hillsides, on sparsely wooded hillsides, and in cultivated fields. November 21 was the latest date of capture of an active individual (UMMZ 113451), the head of which was seen many times prior to capture protruding from a hole beneath the concrete floor of a building. A female (KU 38855), measuring 915 (775 + 140) in total length, and obtained on June 13, contained nine eggs (32 mm. long). One juvenile had eaten a half-grown house mouse, _Mus musculus_; the stomach of a male contained three mice, one a striped field mouse, _Apodemus agrarius_, the other two probably also of that species but too far digested for certain identification. Eggs probably hatch in late summer. A young of the year (length of body, 340) was captured on September 30; another juvenile (length of body, 285) was obtained in May. Our largest male (KU 40123) measured 904 (719 + 185) in total length. Ventrals and subcaudals of six females averaged 205.8 (198-211) and 62.2 (55-69), respectively, whereas corresponding counts of four males averaged 196.8 (190-214), and 71.0 (69-74). Each of nine specimens had dorsal scales in 23-25-19 rows except one (UMMZ 113451), which had 23-25-23 rows. =Elaphe rufodorsata= (Cantor) _Tropidonotus rufodorsatus_ Cantor, Ann. Mag. Nat. Hist., ser. 1, 9:483, August, 1842 (type locality, island of Chusan, China). _Elaphe rufodorsata_, Stejneger, Bull. U. S. Nat. Mus., 58:310, figs. 269-271, July 22, 1907. _Specimens examined_ (27).--7 mi. NW Changhowan-ni, 1 (KU); 3 mi. NW Chip´o-ri, 3 (KU); 7 mi. W Ch´ungju, 2 (KU), 1 (UMMZ); 3 mi. S Kumhwa, 2 (KU); 1 mi. NW Oho-ri, 1 (KU); 4 mi. E Seoul, 1 (KU); 5 mi. E Seoul, 2 (KU); 5 mi. ESE Seoul, 2 (KU); 6 mi. E Seoul, 3 (KU), 2 (UMMZ); 7 mi. ESE Seoul, 5 (KU); 4 mi. N Uijongbu, 1 (KU); 5 mi. NE Uijongbu, 1 (UMMZ). _Remarks._--_E. rufodorsata_ was commonly observed and collected on barren hillsides, on country roads, in rice fields, and along drainage ditches and small streams. One was found sunning outstretched on a road. Two individuals were trapped in cement-walled pits at the Seoul City Water Works. On April 5, five snakes of this species with one _Rhabdophis tigrina_ and one _Agkistrodon halys_, all partly caked with earth, were found sunning in a shallow depression on the side of a Korean burial mound, which was presumably a hibernaculum. Aside from one juvenile, four of the _E. rufodorsata_ were of approximately the same size, having bodies ranging in length from 385 to 455. Copulation was observed on April 25 (male, KU 38811, length of body, 400, and female, KU 38812, length of body, 565), and on May 4 (female, KU 38816, length of body, 620). Eggs doubtless hatch at various times in summer. One of five snakes obtained on April 5 (see above) measured 310 (250 + 60) in total length. Another juvenile (KU 38828), obtained on October 18, was 478 (385 + 93) long, and our smallest specimen of this species (KU 38821), captured on June 26, measured 275 (230 + 45). The stomachs of two snakes each contained a _Rana nigromaculata_; another individual had eaten a _Hyla arborea_, and a fourth specimen had eaten a small fish. One specimen was parasitized by a cestode. The largest female from our series (KU 38816) measured 740 (620 + 120), and the largest male (KU 38813), 595 (475 + 120). Respective ventral and subcaudal counts of 13 males averaged 170.5 (167-174) and 60.0 (56-63), ventrals of 12 females averaged 178.3 (169-182), and subcaudals of 11 averaged 51.0 (46-56). =Elaphe schrencki anomala= (Boulenger) _Coluber anomalus_ Boulenger, Ann. Mag. Nat. Hist., ser. 8, 17:243, March, 1916 (type locality, Chihfeng, China). _Elaphe schrencki anomala_, Pope, The reptiles of China, p. 266, fig. 57, May 11, 1935. _Specimens examined_ (7).--Central National Forest, near Pup´yong-ni, 2 (KU), 1 (UMMZ); 4½ mi. W Chip´o-ri, 1 (KU); 5 mi. N P´yong-taek, 1 (KU); 5 mi. E Seoul, 1 (KU); 5 mi. ESE Seoul, 1 (KU). _Remarks._--Individuals were observed or taken on dry, scrubby hillsides and in grassy upland areas. One of the three snakes from the Central National Forest was captured on a steep, forested hillside among granite outcroppings; another was obtained there along a stream bank and had eaten three bats, _Murina aurata_ (see Jones, 1960:265), and one mouse, _Apodemus_ sp. (tail only found). P. M. Youngman reported (personal communication) finding a rat (_Rattus_ sp.) in the stomach of one individual. A female (KU 38830, length of body, 1180) that was obtained on June 2 contained 17 eggs, each approximately 32 mm. long. The ventrals of two females numbered 223 and 229, and the subcaudals of the latter 70. Ventrals and subcaudals of five males were, respectively, 211, 213, 214, 215, 216, and 71, 75, 75, 69, 75. The coloration and pattern of our seven specimens are of interest in view of the probable intergradation between _E. s. anomala_ and _E. s. schrencki_ in northern Korea (see comments by Shannon, 1956:46). The smallest specimen (KU 38831), having a total length of 335 (280 + 55), was obtained 4 mi. N P´yong-taek on September 24. It is nearly uniform pale brown (lacks a dorsal pattern) and additionally is characterized as follows: incomplete pattern on the head; no black postocular band (pale brown with black posterior border); ventrolateral extensions of the head pattern that form longitudinal stripes of white on the third row of scales; a pale whitish stripe on the sixth and seventh scale rows that extends posteriorly to the level of the fortieth ventral and that has a narrow black border (sometimes interrupted); small and indistinct blackish markings and pale stripes on sides (no higher than sixth row of scales); underside of the head whitish; and venter grayish, having blackish margins on the ends of ventrals posteriorly. KU 38831 is unusual and perhaps anomalous in having a pattern that does not conform to the juvenile pattern of either subspecies. A female (KU 38830), having a total length of 1390 (1180 + 210), from 5 mi. ESE Seoul conforms to descriptions of _anomala_ in being uniformly pale brown above and in having indistinct dark smudges on the sides; the ventral surface is whitish having indistinct dark smudges, brown spots at the ends of each ventral, and the posterior edge of each ventral brown. A male (KU 40125), measuring 1090 (890 + 200) in total length, from 5 mi. E Seoul, is pale brown above and lacks markings on the anterior part of the body. Indistinct dark markings occur at midbody, whereas the posterior quarter of the body and tail have well-defined black bands on a buff background. The black bands posteriorly are arranged in pairs; each pair of bands is separated by two and a half to three scales, whereas the bands of each pair are separated by only one and a half scales. The ventral surface has an obscure marbled pattern. Our largest specimen, a male (UMMZ 113454) having a total length of 1488 (1230 + 258), from the Central National Forest, resembles KU 40125, except that pale brown blotches (29 on body, one blackish on neck) and dark lateral spots occur anteriorly on the body. Another female (KU 38860, body length, 970) from 4½ mi. W Chip´o-ri, our northernmost locality of record, has a fairly distinct pattern dorsally. The 30 dark brown, black-edged blotches that are separated by a buff background are not arranged in pairs (as in KU 40125); the dorsal blotches sometimes alternate with small lateral blotches. The ventral surface is marbled throughout. Two males from the Central National Forest, having total lengths of 1105 (920 + 185) and 830 (690 + 140), generally resemble one another in having the head and neck dark brown or blackish and the anterior part of body dark brown, but discernibly blotched. The posterior part of the body and tail of each bears well-defined blotches (dark brown or black) with buffy interspaces; the dorsal blotches are sometimes arranged in pairs. The ventral surface of each is marbled throughout. These two males are noteworthy in that the pattern anteriorly is obscure, but the ground color is dark, not pale as in the two specimens from the vicinity of Seoul. =Agkistrodon halys brevicaudus= Stejneger _Agkistrodon blomhoffii brevicaudus_ Stejneger, Bull. U. S. Nat. Mus., 58:463, July 22, 1907 (type locality, Pusan, Korea). _Agkistrodon halys brevicaudus_, Okada, A catalogue of vertebrates of Japan, p. 103, 1938. _Specimens examined_ (12).--Central National Forest, near Pup´yong-ni, 4 (KU); 3 mi. NW Chip´o-ri, 2 (KU); 16 mi. NE Mosulp´o, Cheju Do, 1 (UMMZ); 5 mi. E Seoul, 1 (UMMZ); 6 mi. E Seoul, 2 (KU); 7 mi. ESE Seoul, 1 (KU); 7 mi. NNE Sogwi-ri, Cheju Do, 1 (UMMZ). _Remarks._--Individuals of _Agkistrodon_ were collected on brushy or wooded hillsides, along rock walls or in piles of rocks, and in damp, rocky, wooded ravines near streams. Many were docile when captured. One specimen was infested with nematodes, another with cestodes. One specimen had eaten a striped field mouse, _Apodemus agrarius_, and another had eaten a gray hamster, _Cricetulus triton_. One female, obtained on May 22, 6 mi. E Seoul, contained 14 embryos. Another female, obtained on August 25 in the Central National Forest, contained three well-developed embryos. We have not included descriptive or taxonomic remarks concerning _A. halys_ because Dr. Howard K. Gloyd, University of Arizona, who currently is studying the systematics of the genus _Agkistrodon_, has our specimens on loan. Gazetteer Listed below are all localities mentioned in the accounts of species; the latitude (north) and longitude (east) are given for each. All place-names can be found in "Gazetteer to maps of Korea," 3 vols., AMS 2, U. S. Army Map Service, September, 1950, and, except for the two marked by an asterisk, can be located on AMS map series L552 (Korea, 1:250,000). The McCune-Reischauer system of romanization of Korean names is used. Changhowan-ni. 37°07´, 127°38´ Central National Forest. A small mixed forest 15-18 mi. NE Seoul and immediately west of the village of Pup´yong-ni; most of our collecting there was done approximately at 37°45´, 127°10´ Cheju Do (Quelpart Island). A large island in the East China Sea off the southwestern tip of the Korean mainland (see Mosulp´o and Sogwi-ri) Chip´o-ri. 38°08´, 127°19´ Choksong. 37°58´, 126°57´ Ch´onan. 36°48´, 127°09´ *Ch´ongyang-ni. 38°15´, 127°23´ Ch´orwon. 38°15´, 127°13´ Ch´ungju. 36°58´, 127°57´ Halla San. A central, volcanic mountain on Cheju Do (see above) Hoengsong. 37°29´, 127°59´ Inje. 38°04´, 128°11´ Kangnung. 37°45´, 128°54´ Kumhwa. 38°17´, 127°28´ Kunsan. 35°59´, 126°43´ Kwangju. 35°09´, 126°55´ Majon-ni. 37°52´, 126°46´ Mosulp´o. 33°13´, 126°15´ Naegong-ni. 37°41´, 127°10´ Oho-ri. 38°20´, 128°32´ Osan. 37°09´, 127°04´ Pup´yong-ni. 37°44´, 127°12´ Pusan. 35°08´, 129°04´ P´yong-taek [= P´yongt´aeng-ni]. 36°59´, 127°05´ Sangbonch´on-ni. 37°27´, 127°16´ Sangdaehwa. 37°30´, 128°26´ Seoul. 37°32´, 127°00´ Sogwi-ri. 33°15´, 126°34´ Songdong-ni. 38°01´, 127°16´ Taegwang-ni. 38°11´, 127°06´ *Taehoesan-ni. 38°04´, 127°14´ Taejon. 36°20´, 127°26´ Tangjonggok. 38°11´, 128°19´ Tangnim-ni. 37°50´, 127°37´ Uijongbu. 37°44´, 127°03´ Wonsan. 39°09´, 127°27´ Yami-ri. 38°03´, 127°16´ Yanggu. 38°06´, 128°00´ Yongdae-ri. 38°13´, 128°23´ Yongp´yong. 38°01´, 127°13´ Literature Cited BABB, G. H., JR. 1955. An annotated checklist of the amphibians and reptiles of Korea. Bull. Philadelphia Herp. Soc., 1:17-23. BOGERT, C. M., AND OLIVER, J. A. 1945. A preliminary analysis of the herpetofauna of Sonora. Bull. Amer. Mus. Nat. Hist., 83:297-426, 8 pls., 13 figs., 2 maps, March 30. BOULENGER, G. A. 1882. Catalogue of the Batrachia Salientia s. Ecaudata in the collection of the British Museum. Taylor and Francis, London, xvi + 503 pp., 30 pls. CHANG, M. L. Y. 1932. Notes on a collection of reptiles from Szechuan. Contrib. Biol. Lab., Sci. Soc. China, Zool. Ser., 8:9-95, 28 figs., February. CONANT, R. 1951. The reptiles of Ohio. Second edition (with revisionary addenda). Amer. Midland Nat., Univ. Notre Dame Press, 284 pp., 27 pls. DIXON, J. R. 1956. A collection of amphibians and reptiles from west central Korea. Herpetologica, 12:50-56, 1 fig., March 6. FANG, P. W., AND CHANG, M. L. Y. 1931. Amphibia of Nanking. Contrib. Biol. Lab., Sci. Soc. China, Zool. Ser., 7:65-114, 18 figs., May. GÜNTHER, A. 1858. Catalogue of the Batrachia Salientia in the collection of the British Museum. Taylor and Francis, London, xvi + 160 pp., 12 pls. HAHN, D. E. 1959. Observations and collecting notes on _Rana n. nigromaculata_ in central Korea. Jour. Ohio Herp. Soc., 2:7-8, September 20. 1960. Collecting notes on central Korean reptiles and amphibians. Jour. Ohio Herp. Soc., 2:16-24, 4 figs., September 20. JONES, J. K., JR. 1960. The least tube-nosed bat in Korea. Jour. Mamm., 41:265, May 20. LIU, C. 1936. Secondary sex characters of Chinese frogs and toads. Zool. Ser., Field Mus. Nat. Hist., 22:115-156, 12 pls., October 31. 1950. Amphibians of western China. Fieldiana: Zool. Memoirs, Chicago Nat. Hist. Mus., 2:1-400, 10 pls., 100 figs., June 15. MALNATE, E. V. 1960. Systematic division and evolution of the colubrid snake genus Natrix, with comments on the subfamily Natricinae. Proc. Acad. Nat. Sci. Philadelphia, 112:41-71, 2 figs., 4 maps, September 23. MASLIN, T. P. 1950. Snakes of the Kiukiang-Lushan area, Kiangsi, China. Proc. California Acad. Sci., ser. 4, 26:419-466, 10 figs., April 28. MITTLEMAN, M. B. 1950. The generic status of _Scincus lateralis_ Say, 1823. Herpetologica, 6:17-20, June 5. MORI, T. 1928_a_. A presumption of the age in which the separation of Japan and Korea had occurred and the general condition at that age estimated from the distribution of animals in Saishuto and Tsushima. Chosen, pp. 14-25, January, 1928 (in Japanese). 1928_b_. On amphibians and reptiles of Quelpaert Island. Jour. Chosen Nat. Hist. Soc., 6:47-52, March 25 (in Japanese). 1928_c_. On a new Hynobius from Quelpaert Isl. Jour. Chosen Nat. Hist. Soc., 6:53, March 25. MORIYA, K. 1954. Studies on the five races of the Japanese pond frog, _Rana nigromaculata_ Hallowell. I. Differences in the morphological characters. Jour. Sci. Hiroshima Univ. (ser. B, div. 1), 15:1-21, 2 pls., 1 fig., December. OKADA, Y. 1931. The tailless batrachians of the Japanese Empire. Imp. Agric. Exp. Sta., Tokyo, 215 pp., 29 pls., 97 figs., March 30. 1934. A contribution toward a check list of the urodeles of Japan. Copeia, 1934(1):16-19, April 24. 1935. Amphibia of Jehol. Rept. First Sci. Exped. Manchoukuo, sect. V, div. II, pt. II, art. 1, pp. 1-24 (in Japanese) and 25-47 (in English), 7 pls., 9 figs., November 30. OLSEN, L. S. 1957. A new species of _Neoascaris_ (Nematode) from a Korean wood mouse. Trans. Amer. Micros. Soc., 76:205-208, 9 figs., April. POPE, C. H. 1935. The reptiles of China (Natural History of Central Asia, Vol. X). Amer. Mus. Nat. Hist., New York, lii + 604 pp., 27 pls., 78 figs., May 11. POPE, C. H., AND BORING, A. M. 1940. A survey of Chinese Amphibia. Peking Nat. Hist. Bull., 15:13-86, 1 map, September. SATO, I. 1943. The tailed batrachians of Japan. Tokyo, 520 pp., illustrated (in Japanese). SCHLEGEL, H. 1838. Reptilia (_in_ von Siebold, Fauna Japonica), pp. 1-144, illustrated. SCHMIDT, K. P. 1927. Notes on Chinese amphibians. Bull. Amer. Mus. Nat. Hist., 54:553-575, 2 pls., October 14. SHANNON, F. A. 1956. The reptiles and amphibians of Korea. Herpetologica, 12:22-49, 1 pl., 1 fig., March 6. 1957. Addition to the herpetofauna of Korea. Herpetologica, 13:52, March 30. STEJNEGER, L. 1907. Herpetology of Japan and adjacent territory. Bull. U. S. Nat. Mus., 58:xx + 577, 35 pls., 409 figs., July 22. STEWART, G. D. 1953. Notes on a collection of amphibians from central Korea. Herpetologica, 9:146-148, October 30. 1954. A small collection of reptiles from central Korea. Copeia, 1954(1):65-67, February 19. TANNER, V. M. 1953. Pacific Islands herpetology No. VIII, Korea. Great Basin Nat., 13:67-73. TING, H. 1939. A study of the reciprocal hybrids of two species of frogs, _Rana nigromaculata_ and _Rana plancyi_. Peking Nat. Hist. Bull., 13:181-200, 3 pls., March. VAN DENBURGH, J. 1923. A new subspecies of watersnake (_Natrix vibakari ruthveni_) from eastern Asia. Proc. California Acad. Sci., ser. 4, 13:3-4, July 26. WALLEY, H. D. 1958_a_. A new lacertid lizard from Korea. Herpetologica, 14:203-205, 1 fig., December 1. 1958_b_. "The status of _Takydromus kwangakuensis_ Doi." Copeia, 1958(4):338, December 22. _Transmitted June 30, 1961_. 28-8517 
33543	----	UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 15, No. 1, pp. 1-148, pls. 1-6, 11 figs. December 20, 1961 [Transcriber's Note: Words surrounded by cedillas, like ~this~ signifies words in bold. Words surrounded by underscores, like _this_, signifies words in italics.] The Amphibians and Reptiles of Michoacán, México BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1961 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 15, No. 1, pp. 1-148, pls. 1-6, 11 figs. Published December 20, 1961 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED IN THE STATE PRINTING PLANT TOPEKA, KANSAS 1961 The Amphibians and Reptiles of Michoacán, México BY WILLIAM E. DUELLMAN CONTENTS PAGE INTRODUCTION 3 Acknowledgments 5 Historical Account 7 NATURAL LANDSCAPE 9 GEOGRAPHY OF THE HERPETOFAUNA 13 ANNOTATED LIST OF SPECIES 13 Amphibia 14 Caudata 14 Salientia 20 Reptilia 56 Testudines 56 Crocodilia 58 Sauria 59 Serpentes 88 SPECIES OF QUESTIONABLE OCCURRENCE 124 GAZETTEER 129 SUMMARY 141 LITERATURE CITED 142 INTRODUCTION For almost 30 years North American herpetologists have been making extensive collections of reptiles and amphibians in México. Some parts of the country, because of their accessibility, soon became relatively well known; other regions lying off the beaten path were bypassed or inadequately sampled. Principally in the last decade herpetologists have been entering regions from which no collections previously were available in an attempt to fill gaps in known distributions and to discover unknown species of animals. In 1950 Dr. Donald D. Brand led an exploration party from the University of Texas to the poorly explored and faunistically unknown region of southwestern Michoacán. James A. Peters accompanied Brand and collected amphibians and reptiles. In 1951 I welcomed the opportunity to accompany Brand on a second expedition to southwestern Michoacán. Such was the beginning of my interest in the herpetofauna of the region. I have been fortunate to return to Michoacán on four successive trips, all of which had as their purpose the accumulation of data on the herpetofauna that would result in a survey of the component species and an analysis of their distribution. My original intention was to amplify Peters' (1954) study based on the collections made by him in 1950 and by me in 1951 in the Sierra de Coalcomán. But it soon became evident that in order to understand the relationships of the herpetofauna of the Sierra de Coalcomán, the species inhabiting the Tepalcatepec Valley and adjacent mountain ranges would have to be studied. In the course of making that study I examined all specimens from Michoacán already in museums. There have been few detailed herpetofaunal studies in México. The first such study of any consequence was that by Bogert and Oliver (1945) on the herpetofauna of Sonora. In that paper the authors analyzed the fauna from a geographic view and showed the transition from tropical species in the southern part of the state to members of the Sonoran Desert assemblage to the north. Martin (1958) made a detailed study of the herpetofauna of the Gómez Farías region in southern Tamaulipas; he emphasized the ecological distribution of amphibians and reptiles in that region with special reference to cloud forests. Duellman (1958c) presented a preliminary geographic analysis of the herpetofauna of Colima with special reference to the continuity of the species inhabiting the lowlands. Zweifel (1960) discussed in detail the herpetofauna of the Tres Marías Islands and commented on the derivation of the fauna. Duellman (1960d) provided a detailed account of the geographic distribution of the amphibians known to occur in the lowlands of the Isthmus of Tehuantepec and attempted to account for the present patterns of distribution. The present report is the first of two parts dealing with the herpetofauna of Michoacán. The purpose of this part is to present a full account of the species of amphibians and reptiles known to inhabit the state of Michoacán; the accounts of the species are accompanied by a brief description of the natural landscape and of the various assemblages of species comprising the major faunistic groups within the region. A gazetteer of collecting localities is appended. The second part of the study, now in preparation, deals with the ecological and historical geography of the herpetofauna. Since the present part will be of interest primarily to systematic herpetologists, I have decided to separate it from the more general material of interest to biogeographers. One of the major problems that faces the worker undertaking a faunal study is the presence of species or genera of unsettled systematic status. My work in Michoacán has been no exception; fifteen separate studies were undertaken in an attempt to solve systematic problems in certain groups. Some systematic problems still remain but are of little consequence insofar as the entire faunal picture is concerned, or are so involved as to be impractical to undertake at this time. In accounts of species, such problems are mentioned in the hope that they will interest some worker who will be inclined to investigate them. ACKNOWLEDGMENTS While engaged in the study of the herpetofauna of Michoacán I have built up a debt of gratitude to many individuals, without whose aid my ambition to complete my study never would have been realized. I am especially grateful to those individuals who accompanied me in the field; Lee D. Beatty, Richard E. Etheridge, Carter R. Gilbert, Fred G. Thompson, Jerome Tulecke, and John Wellman offered stimulating companionship and valuable assistance. On many occasions they suffered hardships on behalf of my interests. Studies of my own specimens have been augmented by material from other institutions. For permitting me to examine specimens in their care I am indebted to W. Frank Blair, Charles M. Bogert, Doris M. Cochran, William B. Davis, James R. Dixon, the late Emmett R. Dunn, Josef Eiselt, Alice G. C. Grandison, Norman Hartweg, Robert F. Inger, Arthur Loveridge, the late Karl P. Schmidt, Hobart M. Smith, Robert C. Stebbins, Margaret Storey, Edward H. Taylor, and Richard G. Zweifel. Several people have aided me in the study of specimens and in the analysis of data; I am grateful to Donald D. Brand, who first introduced me to Michoacán; since that time I have benefited much from his knowledge of the area. James A. Peters provided me with essential information concerning his field work in southern Michoacán in 1950. James R. Dixon and Floyd L. Downs have permitted me to use freely the material and data that they accumulated in their recent field work in Michoacán. Norman E. Hartweg allowed me to use the specimens and data that he gathered in his survey of the herpetofauna in the region of Volcán Parícutin. L. C. Stuart, Charles F. Walker, and Richard G. Zweifel have helped in unraveling some of the systematic and distributional problems. I am especially grateful to my wife, Ann, who for six months helped me track down elusive species and explore new areas. Furthermore, she has stimulated me to carry this study to completion. Many people in Michoacán favored the field parties with quarters, transportation, and valuable information, which greatly facilitated the field work. In this respect I am especially indebted to Ingeniero Ruben Erbina of Ingenieros Civiles Asociados, who not only let us use his home as our headquarters, but through a letter of introduction gave us the "key" to southern Michoacán. Ingeniero Pedro Tonda aided us in Arteaga and San Salvador. Ingeniero Anastacio Peréz Alfaro of the Comisión Tepalcatepec in Uruapan provided the latest maps of southern Michoacán and much essential information pertaining to travel conditions in the area. Señor Nefty Mendoza gave us a home in Dos Aguas; this kindness allowed us to work in this interesting region during the height of the rainy season. Mr. and Mrs. Bob Thomas let us make use of their facilities at Hacienda Zirimícuaro. The naval officers at the Estación Marina at Playa Azul made pleasant what might have been a dreadful stay in that small coastal village. To the managers and pilots of Lineas Aereas Picho in Uruapan I owe special thanks for going out of their way on more than one occasion to transport a stranded snake-hunter. Throughout the months of field work beginning in 1955 I constantly have been aided by the authorities and workers of the Comisión Tepalcatepec, a subdivision of the Secretaria de Caminos y Obras Publicas, and of the private corporation, Ingenieros Civiles Asociados. Much of the field work in Michoacán was made possible only through the co-operation of the natives who supplied mules, acted as guides, and aided in the collection of specimens. I have learned a great deal from these people. They will never see this report. Their work as guides, muleteers, and collectors greatly assisted me with the mountains of equipment that had to be piled on the backs of scrawny mules for transportation to places where the natives seldom trod. Their efforts in behalf of Don Guillermo never will be forgotten; I extend an especially hearty _muchas gracias_ to Benjamin, Ignacio, Jesús, Lorenzo, Mariano, and Remigio. Much of the work on this report was done while I was associated with the Museum of Zoology at the University of Michigan. I thank Norman E. Hartweg and T. H. Hubbell for making available to me the facilities of the museum and for their numerous courtesies that aided me so much. My field work in Michoacán was supported by the Museum of Zoology at the University of Michigan (1951), by the Horace H. Rackham School of Graduate Studies of the University of Michigan (1955), by the Penrose Fund of the American Philosophical Society (1956), by the Bache Fund of the National Academy of Sciences (1958), and by the University of Kansas Endowment Association (1960). Permits for collecting specimens in México were provided by the Dirección General de Caza through the courtesy of Ing. Juan Lozano Franco and Luis Macías Arellano. Historical Account Unlike many parts of southern México and northern Central America, Michoacán received no attention from the collecting expeditions of the European museums in the last century. The earliest known herpetological specimens from Michoacán were obtained by Louis John Xantus, who was appointed U. S. Consul to Colima in 1859. In April, 1863, Xantus collected at Volcán Jorullo in Michoacán; in April and May of the same year he collected along the coast of Michoacán between the Río Cachán and the Río Nexpa. His small collection of 19 extant specimens is in the United States National Museum. Alfredo Dugès, a resident of Guanajuato, México, made early contributions to the knowledge of the herpetofauna of Michoacán. In 1885 he described _Sonora michoacanensis_, and in 1891 he described _Eumeces altamirani_; from what is known of the distribution of these species, he probably had collected in the Tepalcatepec Valley. During their biological survey of México, Edward W. Nelson and Edward A. Goldman spent a limited amount of time in Michoacán in 1892 and again in 1903 and 1904. Most of their collecting was done on the plateau in the north-central part of the state; their collections are in the United States National Museum. While collecting fishes in southern México, Seth E. Meek obtained some amphibians and reptiles from Lago de Pátzcuaro in 1904; these are in the collections of the Chicago Natural History Museum. In 1908 Hans Gadow ventured into the then unexplored "tierra caliente" of the Balsas Valley and collected at Volcán Jorullo and other localities in the valley. Later in the same year he collected at Guayabo, San Salvador, and Arteaga in the Sierra de Coalcomán and at Buena Vista and Cofradía in the Tepalcatepec Valley. His collections were deposited in the British Museum (Natural History) and the Naturhistorisches Museum Wien. The first thirty years of the present century saw little more field work in Michoacán. In the 1930's Edward H. Taylor and Hobart M. Smith collected throughout much of México. At various times they worked in Michoacán, principally along the road from México City to Guadalajara. In 1935 Hobart M. Smith spent a week at Hacienda El Sabino south of Uruapan; he revisited the locality again in 1936 and made a large and important collection of amphibians and reptiles from the upper limits of the arid tropical scrub forest in the Tepalcatepec Valley. Specimens collected by Smith and Taylor were incorporated into the Edward H. Taylor-Hobart M. Smith collection, which subsequently was deposited in part in the Museum of Natural History at the University of Illinois and in part in the Chicago Natural History Museum. In 1939 Hobart M. Smith collected at Pátzcuaro and between Uruapan and Apatzingán; these collections, made while he was a Walter Rathbone Bacon Scholar of the Smithsonian Institution, are deposited in the United States National Museum. In 1940 and 1941 Frederick A. Shannon, who was a member of the Hoogstraal Expeditions under the auspices of the Chicago Natural History Museum, collected on Cerro de Tancítaro and at Apatzingán; an account of the specimens collected there was published by Schmidt and Shannon (1947). The eruption of Volcán Parícutin in February, 1943, attracted the attention of many biologists, a group of which from the Museum of Zoology at the University of Michigan collected in the Cordillera Volcánica in 1945 and 1947. The amphibians and reptiles were collected and studied by Norman E. Hartweg. In 1950 James A. Peters accompanied Donald D. Brand on a preliminary exploration of the western part of the Sierra de Coalcomán and adjacent Pacific coast of Michoacán; in the same year Peters collected also on the Mexican Plateau and at Volcán Jorullo. His specimens are in the Museum of Zoology at the University of Michigan. Since 1950 many biologists have collected in Michoacán in the course of work on certain groups of animals or in general surveys. In this way Raymond Alcorn, Robert W. Dickerman, James R. Dixon, Floyd L. Downs, Emmet T. Hooper, and Robert R. Miller have contributed to our knowledge of the herpetofauna. As stated previously, my own field work in Michoacán began in 1951, when I accompanied Donald D. Brand on an exploring expedition to the southern part of the state. In that year a short time was spent on the Mexican Plateau, principally in the area around Lago de Cuitzeo, and at Volcán Jorullo. In July and August we made our headquarters at Coalcomán. From that town the field party travelled southward to Maruata on the Pacific coast and thence back over the mountains to Coalcomán. Later in that summer we travelled by mule from Coalcomán southeastward to the mouth of the Río Nexpa. In 1955, accompanied by Lee D. Beatty, Carter R. Gilbert, and Fred G. Thompson, I collected in the Tepalcatepec Valley and at Coalcomán. We made a mule trip from Coalcomán to Cerro de Barolosa, where we made the first collections from the pine-fir forests in the Sierra de Coalcomán. Later in the same summer Carter R. Gilbert and I spent a week at Playa Azul on the Pacific coast. In March, April, and May, 1956, my wife and I collected for a short time in the Cordillera Volcánica and on the Mexican Plateau. In early April we moved into the Tepalcatepec Valley, where we collected intensively between Churumuco and Tepalcatepec. In May we collected on the Pacific coast between Boca de Apiza and La Placita. In July and August, 1956, accompanied by Richard E. Etheridge, we returned to Michoacán and again collected on the Mexican Plateau and in the Cordillera Volcánica, before moving into the Tepalcatepec Valley. In an attempt to fill in gaps in the known distributions of many species and to sample the fauna in some previously uncollected areas, I returned to Michoacán in June, 1958. Accompanied by Jerome B. Tulecke and John Wellman, I collected on the Mexican Plateau in the northwestern part of the state, on the southern slopes of the Cordillera Volcánica, and in the Tepalcatepec Valley. Most of our time was spent in the Sierra de Coalcomán, where we collected at Aguililla, Artega, and Dos Aguas. In 1960 two days were spent in Michoacán; a small collection was made in the eastern part of the Cordillera Volcánica. With the exception of the specimens collected in 1960, which are at the Museum of Natural History at the University of Kansas, the specimens that I have collected in Michoacán are in the Museum of Zoology at the University of Michigan. NATURAL LANDSCAPE A proper understanding of the geographical distribution of animals in a given region is possible only after a thorough acquaintance with the geography of the region. Likewise, in order to gain a knowledge of the ecological distribution and relationships of the components of the fauna, it is necessary to study the animals in their natural environments. In order to give the reader a picture of the physical features and the major animal habitats within the state of Michoacán, the following brief description is offered. Each of these facets mentioned below will be elaborated in detail in my final report on the herpetofauna of Michoacán. Physiography The state of Michoacán comprises an area of 60,093 square kilometers (Vivó, 1953). Within this area the rugged terrain has a total relief of nearly 4000 meters. There have been several attempts to classify the physiographic provinces of México; the classification used here is a slight modification of the scheme proposed by Tamayo (1949). I have tried to keep the system as simple as possible, but still useful in discussing the distribution of animals living in the region. For general purposes the state of Michoacán can be divided into lowlands and highlands as follows: LOWLANDS Pacific Coastal Plain Balsas-Tepalcatepec Basin HIGHLANDS Mexican Plateau Cordillera Volcánica Sierra de Coalcomán Although the lowlands in the state are continuous, they are only narrowly connected and thus form two distinct physiographic and biotic areas. The Pacific Coastal Plain in Michoacán extends for a distance of about 200 kilometers (airline) from the Río Coahuayana to the Río Balsas. The coastal plain is broad between the Río Coahuayana and San Juan de Lima, and between Las Peñas and the Río Balsas, where the hills rise some 12 kilometers inland from the sea. Between San Juan de Lima and Las Peñas the mountains extend to the sea; in this region rocky promontories form precipitous cliffs dropping into the sea. Between the promontories are small sandy or rocky beaches. Lying to the north of the Sierra de Coalcomán and the Sierra del Sur, but south of the Cordillera Volcánica, is a broad structural depression, the Balsas-Tepalcatepec Basin. The western part of this basin, which separates the Sierra de Coalcomán from the Cordillera Volcánica, is the valley of the Río Tepalcatepec, a major tributary of the Río Balsas. The eastern part of the basin is the valley of the Río Balsas. From the point of junction of the two rivers, the Río Balsas flows southward through a narrow gorge, which separates the Sierra de Coalcomán from the Sierra del Sur, to the Pacific Ocean. In Michoacán the floor of the Balsas-Tepalcatepec Basin varies from 200 to 700 meters above sea level. The central part of México is a vast table-land, the Mexican Plateau, the southern part of which extends into northern Michoacán. In this region the terrain is rolling and varies from 1500 to 1900 meters above sea level. Many small mountain ranges rise from the plateau and break the continuity of the rolling table-land. Located on the southern part of the Mexican Plateau in Michoacán are several lakes, the largest of which are Lago de Chapala, Lago de Cuitzeo, and Lago de Pátzcuaro. Bordering the southern edge of the Mexican Plateau is a nearly unbroken chain of volcanos, the Cordillera Volcánica. The highest peaks in Michoacán, Cerro San Andrés (3930 meters) and Cerro de Tancítaro (3870 meters), are in this range. Parts of the Cordillera Volcánica in Michoacán are known by separate names; these are, from west to east: Sierra de los Tarascos, Sierra de Ozumatlán, and Serranía de Ucareo. Lying between the Tepalcatepec Valley and the Pacific Ocean, and east of the Río Coahuayana and west of the Río Balsas, is an isolated highland mass, the Sierra de Coalcomán. This mountain range rises to elevations of slightly more than 3000 meters. It has a length of about 200 kilometers and a width of about 80 kilometers. Except for a relatively low connection with the Cordillera Volcánica, the Sierra de Coalcomán is isolated from other mountain ranges in southwestern México. CLIMATE The climates in Michoacán vary from tropical in the lowlands to cool temperate at high elevations in the Sierra de Coalcomán and Cordillera Volcánica. The highest temperatures are known in the Balsas-Tepalcatepec Basin, where at Churumuco the mean annual temperature is 29.3° C. and the range of monthly means is 3.5° C. (Contreras, 1942). Frosts occur sporadically on the Mexican Plateau, and in the winter snow falls on the highest mountains. Precipitation varies geographically and seasonally. Most of the rain falls between June and October. In the Balsas-Tepalcatepec Basin rainfall in the rest of the year is negligible. The annual average rainfall at Coahuayana on the Pacific Coastal Plain is 871 mm. (Guzmán-Rivas, 1957:52). In the Balsas-Tepalcatepec Basin rainfall seldom exceeds 800 mm. per year. In the mountains precipitation is heavier and somewhat more evenly distributed throughout the year, but still definitely cyclic. For example, Uruapan (elevation, 1500 meters) receives an average annual rainfall of 1674 mm. (Contreras, 1942). The prevailing winds are from the Pacific Ocean. The southern (windward) slopes of the Sierra de Coalcomán probably receive more rain than any other part of the state. The Balsas-Tepalcatepec Basin lies in a rain shadow of the Sierra de Coalcomán, and the Mexican Plateau lies in a somewhat less drastic rain shadow of the Cordillera Volcánica; these are the driest regions in the state. VEGETATION AND ANIMAL HABITATS For the purposes of this report I have adopted the classification of types of vegetation that seem to me most significant in terms of ecological distribution of reptiles and amphibians in Michoacán. These types are as follows: TEMPERATE (1000-4000 meters) Fir Forest (2400-4000 meters) Pine-oak Forest (1000-4000 meters) Mesquite-grassland (1500-2100 meters) TROPICAL (0-1000 meters) Arid Tropical Scrub Forest (0-1000 meters) Tropical Semi-deciduous Forest (150-600 meters) The vegetation of the Pacific Coastal Plain and the Balsas-Tepalcatepec Basin consists of arid tropical scrub forest, composed of deciduous trees, which in many places are stunted and widely spaced. In the dry season there is little cover provided by this forest. In the rainy season there is a sparse growth of grasses and some shade provided by the small leaves of the thorny trees. In Michoacán the rainfall is heaviest on the southern slopes of the Sierra de Coalcomán and somewhat less so on the southwestern slopes of the Cordillera Volcánica. At these relatively low elevations (150 to 600 meters) there is tropical semi-deciduous forest, characterized by relatively dense shade throughout the year and by a leaf mulch on the ground. This type of forest forms the gallery forest along the larger streams in the Balsas-Tepalcatepec Basin and on the Pacific Coastal Plain. Rainfall also is heavy on the high mountain ridges, where temperatures are low. On these ridges, fir forest, often mixed with pine and oaks, is found. This habitat is characterized by a cool, moist climate, many rotting logs, and a moist ground cover of leaves and needles. Most of the mountains are covered with pine-oak forest, which in most places is decidedly subhumid, but where this forest occurs on the windward sides of high ridges, it sometimes is noticeably humid. In this forest the important animal habitats include the needle- and leaf-litter, and in some areas, bromeliads. The rolling terrain of the Mexican Plateau supports cacti, small leguminous trees, and grasses. Like the arid tropical scrub forest, this type of vegetation, the Mesquite-grassland association, is deciduous and thus provides little shelter in the dry season. Unlike the areas in which arid tropical scrub forest is developed, the Mesquite-grassland is found in areas having warm days and cool nights. GEOGRAPHY OF THE HERPETOFAUNA Although the main part of my final report on the herpetofauna of Michoacán will deal with the geographical and ecological patterns of distribution of the herpetofauna, a brief summary of the faunal assemblages is presented here. In Michoacán there are two major faunal assemblages, one in the lowlands, and one in the highlands. A large number of the species inhabiting the lowlands are wide-ranging species, such as _Bufo marinus_, _Iguana iguana_, and _Boa constrictor_. Sixty-three species are known to occur on the Pacific Coastal Plain; 41 of these, together with 36 others occur in the Balsas-Tepalcatepec Basin, a physiographic region to which several species of reptiles are endemic; for example, _Enyaliosaurus clarki_, _Urosaurus gadowi_, _Cnemidophorus calidipes_, and _Eumeces altamirani_. Generally speaking, the members of the highland faunal assemblage have more restricted geographic ranges. The major exceptions are those species that are widely distributed on the Mexican Plateau, such as: _Bufo compactilis_, _Sceloporus torquatus_, and _Salvadora bairdi_. In the montane habitats of the Cordillera Volcánica, 45 species of amphibians and reptiles are known; 34 species have been found in the Sierra de Coalcomán. Fourteen species are known to occur in both ranges. Several species are known only from the Cordillera Volcánica and adjacent highlands, and three species are endemic to the Sierra de Coalcomán. ANNOTATED LIST OF SPECIES In the following pages the 176 species and subspecies of amphibians and reptiles known to occur in the state of Michoacán are discussed in relation to their variation, life histories, ecology, and distribution in the state. Data have been gathered from 9676 specimens. I have not prolonged the accounts of species with information that has been presented elsewhere. Consequently, the length and completeness of the accounts are variable. I have given only the information that I consider a worthwhile contribution to our knowledge of the particular species. The synonymies given at the beginning of each account include the first use of the trivial name by the original author, the first usage of the combination that I am using, and, if the circumstances make it necessary, additional names or combinations that have been proposed since the publication of the checklists of Mexican amphibians and reptiles by Smith and Taylor (1945, 1948, and 1950b). References cited only in the synonymies are not listed in the Literature Cited. Preceding the discussion of each species is an alphabetical list of the localities in Michoacán from which specimens have been examined. The listing of a locality means that one or more specimens, as indicated, has been examined from that locality. Only for those specimens especially mentioned in the text are catalogue numbers given. Abbreviations for the various museums and scientific collections are, as follows: AMNH American Museum of Natural History ANSP Academy of Natural Sciences of Philadelphia BMNH British Museum (Natural History) CNHM Chicago Natural History Museum EHT-HMS Edward H. Taylor-Hobart M. Smith collection JRD James R. Dixon collection, College Station, Texas KU University of Kansas Museum of Natural History MCZ Museum of Comparative Zoology MVZ Museum of Vertebrate Zoology NMW Naturhistorisches Museum Wien SU Stanford University Museum of Natural History TCWC Texas Cooperative Wildlife Collection UIMNH University of Illinois Museum of Natural History UMMZ University of Michigan Museum of Zoology USNM United States National Museum UTNHC University of Texas Natural History Collection Throughout the accounts of the species all measurements are given in millimeters; if the range of variation is given, the mean follows in parentheses. AMPHIBIA Caudata ~Ambystoma amblycephalum~ Taylor _Ambystoma amblycephala_ Taylor, Univ. Kansas Sci. Bull., 26: 420, November 27, 1940.--Fifteen kilometers west of Morelia, Michoacán, México. Fifteen km. W of Morelia (19); 11 km. SSE of Opopeo (12); 8 km. S of Pátzcuaro; 24 km. S of Pátzcuaro (2); Quiroga (20); Tacícuaro (167). Taylor and Smith (1945:530) presented data on 137 specimens collected at Tacícuaro on October 1, 1939; these are all larvae and metamorphosing individuals. Aside from these, the largest larva examined (UMMZ 104962 from 15 km. W of Morelia) has a snout-vent length of 70.0 mm. and a tail length of 53.5 mm. The larvae are pale pinkish tan above and somewhat paler below; there is a lateral row of cream colored spots. The tail-fin, which is deepest at mid-length, extends to the back of the head and is flecked with brown. In small larvae the outer edge of the tail-fin is dark brown. The eyes are large. Two small metamorphosed specimens (UMMZ 98967) from 24 kilometers south of Pátzcuaro are tentatively referred to this species. These specimens have body lengths of 49.0 and 45.0 mm. and tail lengths of 36.0 and 31.5 mm., respectively. They have 17-17 and 16-15 vomerine teeth arranged in a broad arch behind the choanae, 10 costal grooves, and 7 intercostal spaces between adpressed toes. The dorsal color is uniform brown; that of the venter is a dusty cream. Larvae were collected from shallow ponds near Quiroga and 15 kilometers west of Morelia; metamorphosed individuals were taken from beneath logs in pine and fir forests at elevations from 2300 to 2800 meters. ~Ambystoma dumerili dumerili~ (Dugès) _Siredon Dumerili_ Dugès, La Naturaleza, 1:241, 1870--Lago de Pátzcuaro, Michoacán, México. _Bathysiredon dumerilii_, Dunn, Notulae Naturae, 36:1, November 9, 1939. _Bathysiredon dumerilii dumerilii_, Maldonado-Koerdell, Mem. y Rev. Acad. Nac. Cien., 56:199, 1948. _Ambystoma_ (_Bathysiredon_) _dumerili_, Tihen, Bull. Florida State Mus., 3:3, June 20, 1958. Lago de Pátzcuaro (22);? Morelia. For many years this unusual salamander was known from only a few specimens mostly collected in the last century; Smith and Taylor (1948:7) stated: "It is presumed that this species is extinct owing to the introduction of exotic game and food fishes." In 1951 and in 1955 I had been told that _axolotls_ were sold in the market at Pátzcuaro; nevertheless, none was found on my visits there. In 1956 Charles M. Bogert obtained several large specimens at the market in Pátzcuaro. These establish the continued existence of the salamander in Lago de Pátzcuaro. On January 27, 1955, R. W. Dickerman procured a specimen (KU 41573) in the market at Morelia. Since fish are brought to Morelia from Lago de Pátzcuaro, the specimen probably was from that lake. Nevertheless, the species may occur in other permanent bodies of water in Michoacán. Maldonado-Koerdell (1948) described _Bathysiredon dumerili queretarensis_ from San Juan del Río, Queretaro. This locality is about 200 airline kilometers northeast of Lago de Pátzcuaro and is in the Río Moctezuma drainage. ~Ambystoma ordinarium~ Taylor _Ambystoma ordinaria_ Taylor, Univ. Kansas Sci. Bull., 26:422, November 27, 1940.--Four miles west of El Mirador, near Puerto Hondo, Michoacán, México. Axolotl (56); Cerro San Andrés; 22 km. W of Mil Cumbres; 46 km. E of Morelia (34); 8 km. SE of Opopeo (5); Puerto de Garnica (8); Puerto Hondo (41); San Gregorio (16); San José de la Cumbre (20). Of 16 specimens (KU 51520-35) collected on June 18, 1955, near San Gregorio, 15 are adult females with swollen cloacae and minute ovarian eggs. Possibly these specimens had just recently deposited their mature eggs. In preservative the specimens are black above and dull creamy gray below. Measurements for the 15 females are: snout-vent length, 80.0-102.0 (92.5); tail length, 69.0-93.0 (84.2); head width, 15.8-20.5 (17.7); head length, 22.8-26.6 (24.4). A larval specimen with small gills has a snout-vent length of 72 mm. and a tail length of 62 mm. Three specimens have 12 costal grooves; the other have 11. Of 20 specimens from San José de la Cumbre (UMMZ 112857 and 115143), 14 are neotenic adults; the others are larvae. In life the salamanders were blackish to olive-brown above with scattered cream-colored dots on the dorsum and flanks but in preservative are dull grayish black with indistinct pale spots and dark reticulations. The belly is pale gray with indistinct dark spots. Eleven females and three males have the following measurements, respectively: snout-vent length, 76.0-90.0 (80.7), 64.0-84.0 (74.3); tail length, 70.0-81.0 (75.0), 58.0-71.0 (66.7); head width, 19.5-23.5 (20.7), 17.5-20.5 (19.3); head length, 22.0-25.0 (23.0), 20.0-22.5 (21.5). The smallest larva has a snout-vent length of 43.0 mm. and a tail length of 38.0 mm. Two individuals have 12 costal grooves; the others have 11. All of the females contained eggs, the largest of which were 1.5 mm. in diameter. The stomachs of most of the specimens were distended with oligochaets, aquatic insect larvae, and small aquatic beetles. A series of 34 larvae (JRD 5904-37) from 46 kilometers east of Morelia are tentatively referred to this species. These specimens are olive-brown above with cream-colored spots on the flanks; the dorsal tail-fin does not extend onto the body. This species has been found only at elevations in excess of 2400 meters in pine and fir forests. At Rancho Axolotl James A. Peters collected larvae and neotenic individuals in a rocky stream and adults from beneath rocks and logs in the forest near the stream. Neotenic individuals and larvae were found in a clear stream in pine-fir forest at an elevation of 2700 meters near San José de la Cumbre; specimens were collected there in July, 1955, and again in July, 1956. The site was visited in April, 1956, at which time the stream consisted of only a few puddles; no salamanders were found. ~Ambystoma tigrinum velasci~ Dugès _Ambystoma velasci_ Dugès, La Naturaleza, ser. 2, 1:142, 1888.--Laguna Santa Isabel, near Guadalupe Hidalgo, Distrito Federal, México. _Ambystoma tigrinum velasci_, Dunn, Copeia, no. 3:157, November 14, 1940. Pátzcuaro (5); Tacícuaro (9). Definite specific assignment of these specimens, all larvae, cannot be made at this time. They have shovel-shaped heads and laterally compressed bodies with the dorsal tail-fin extending anteriorly to the back of the head. The eyes are small. The body is pale tan with dark mottling on the tail and flanks. The average snout-vent length for nine specimens from Tacícuaro is 61.0 mm. The larvae from Tacícuaro (UMMZ 89255) were collected by Dyfrig Forbes in October, 1939; those from Pátzcuaro, presumably Lago de Pátzcuaro (BMNH 1914.1.28-247-8 and CNHM 948), were collected by Hans Gadow and Seth Meek in 1908. ~Pseudoeurycea belli~ (Gray) _Spelerpes belli_ Gray, Catalogue Batrachia Gradientia British Museum, p. 46, 1850.--México. Type locality restricted to 2 miles east of Río Frío, Puebla, México, by Smith and Taylor (1950a:341). _Pseudoeurycea bellii_, Taylor, Univ. Kansas Sci. Bull., 30:209, June 12, 1944. Axolotl (2); Carapan; Cerro Tancítaro (84); Macho de Agua; 22 km. W of Mil Cumbres; Opopeo; Pátzcuaro (8); Puerto Hondo (2): San José de la Cumbre; San Juan de Parangaricutiro (42); Uruapan (5); Zacapu (4). This salamander seems to reach its greatest abundance in Michoacán in the Sierra de los Tarascos between Pátzcuaro and Tancítaro, where it is found at elevations from 1500 to 2900 meters. It is found less commonly in the eastern part of the Cordillera Volcánica in Michoacán, where it sometimes occurs in association with _Pseudoeurycea robertsi_. On June 22 and 23, 1955, four clutches of eggs of this species were found beneath adobe bricks and rocks on the volcanic ash that has buried the village of San Juan de Parangaricutiro. The eggs were unstalked and separate, but adherent in clumps of three or four (Pl. 2, Fig. 1). The outer membranes were covered with fine particles of ash. The ash beneath the stones where the eggs were found was only slightly moist; one clump of eggs was partially desiccated. Three complete clutches have 20, 23, and 34 eggs; one clutch of 15 eggs was being eaten by beetles (Tenebrionidae: _Eleodes_ sp.). The eggs vary in size from 4.6 to 6.5 mm. and average 5.3 mm. in diameter. They are unpigmented. Surrounding the embryo is a vitelline membrane, an inner, and an outer envelope (Fig. 1). In an average-sized egg having an embryo 4 mm. in length, the diameter of the outer membrane is 5.3 mm., the inner membrane 5.0 mm., and the vitelline membrane 4.6 mm. All of the eggs contained embryos in which the limb buds were developed; in about half of these the eyes were distinctly visible. [Illustration: Fig. 1. Diagram of an egg of _Pseudoeurycea belli_ from San Juan de Parangaricutiro, Michoacán. × 10.] The first heavy rain of the season occurred on the night of June 22, 1955. Thus, at least sometimes, _Pseudoeurycea belli_ lays its eggs before the onset of the rainy season. A female having a snout-vent length of 110 mm., collected on June 22, 1955, contained 36 ovarian eggs having diameters from 3.0 to 3.5 mm. The fact that small juveniles were collected on the same date indicates that this salamander lays eggs over a period of several weeks in late spring and early summer. The smallest juvenile examined has a snout-vent length of 17.0 mm. and a tail length of 7.5 mm. Twelve juveniles from the vicinity of San Juan de Parangaricutiro have an average snout-vent length of 19.4 mm. and an average tail length of 9.7 mm. In juveniles the adpressed limbs either touch or overlap by one intercostal space; in adults there are two or three intercostal spaces between adpressed toes. Therefore the greatest number of intercostal spaces between adpressed limbs is found in the largest specimens. A similar relationship between adpressed limbs (= length of limbs) and snout-vent length was shown for _Plethodon richmondi_ by Duellman (1954a). The number of vomerine teeth is variable; the number of teeth seems to be closely correlated with the size of the salamander (Fig. 2). A similar correlation between the number of maxillary teeth and body length was reported for _Chiropterotriton multidentatus_ by Rabb (1958). In 12 juvenile _Pseudoeurycea belli_ there are 6-13 (8.8) vomerine teeth, and in 11 adults having snout-vent lengths greater than 90 mm. there are 39-49 (44.0) vomerine teeth. The coloration of the juveniles resembles that of the adults (Pl. 1). [Illustration: FIG. 2. Correlation between the number of vomerine teeth and snout-vent length in 79 _Pseudoeurycea belli_ from Michoacán.] The differences between this species and _Pseudoeurycea gigantea_ are minor. Taylor (1939a) distinguished _gigantea_ from _belli_ by the larger size, fewer intercostal spaces between adpressed limbs, more vomerine teeth, and absence of occipital spots in _gigantea_. Taylor and Smith (1945) stated that in life the spots in _gigantea_ are orange instead of red as in _belli_. Five specimens of _Pseudoeurycea belli_ from Michoacán, including one juvenile, lack occipital spots. In the 34 living individuals that I have seen from Michoacán the spots varied from deep red to orange. Therefore, of the characters listed by Taylor (_op. cit._) to diagnose _Pseudoeurycea gigantea_, only the over-all larger size and smaller number of intercostal spaces between adpressed limbs (= relatively longer limbs) are useful in separating _Pseudoeurycea belli_ and _gigantea_. ~Pseudoeurycea robertsi~ (Taylor) _Oedipus robertsi_ Taylor, Univ. Kansas Sci. Bull., 25:287, July 10, 1939.--Nevado de Toluca, México. _Pseudoeurycea robertsi_ Taylor, Univ. Kansas Sci. Bull., 30:209, June 12, 1944. Atzimba (3); Macho de Agua (9); Puerto Lengua de Vaca (14). Previously this species has been recorded only from the type locality. In July, 1956, individuals referable to this species were found at two sites in pine-fir forest immediately to the east of Macho de Agua and in pine-oak-fir forest at Atzimba. On August 20, 1958, a series was collected in pine-fir forest at Puerto Lengua de Vaca. These localities are between 2900 and 3000 meters in the Cordillera Volcánica in eastern Michoacán. In life the coloration of these salamanders was highly variable. The belly and undersurfaces of the tail and hind limbs were pale gray, with or without silvery white flecks; the chin was a cream-color and flecked with silvery white in some specimens. The middorsal area was brown, orange-brown, or dull grayish yellow. The flanks and lateral surfaces of the tail were black with yellowish flecks or streaks on the flanks and yellowish or orange-brown flecks on the tail. The iris was golden brown. Measurements of eight males and two females are, respectively: snout-vent length, 42.5-56.0 (49.5), 54.0-60.0 (57.0); tail length, 42.0-56.0 (48.1), 52.0-55.0 (53.5). The smallest juvenile has a snout-vent length of 28.0 mm. and a tail length of 23.0 mm. Of the 26 available specimens, six have 12 costal grooves, and the others have 11. In comparison with 36 topotypes, the specimens from Michoacán have a less striking dorsal color pattern; none has a well-defined dorsal reddish brown area or bold reddish mottling on the tail. Furthermore, the specimens from Michoacán have paler venters than do topotypic specimens. Salientia ~Rhinophrynus dorsalis~ Duméril and Bibron _Rhinophrynus dorsalis_ Duméril and Bibron, Erpétologie générale, vol. 8:758, 1841.--Veracruz, Veracruz, México. Mouth of the Río Balsas (10). These specimens (BMNH 1914.1.28.181-90) were collected by Gadow in 1908 and reported by him (1930:72): "Whilst this very sluggish termite-eating toad is common enough in the sweltering hot country of the state of Vera Cruz, up to an elevation of 1500 feet, it was unknown on the west side of the Isthmus until I found it in great numbers near the mouth of the Balsas River, in and near fresh-water pools, where it attracted attention by its loud peculiar voice during the pairing season in the month of July." Subsequently, Peters (1954:3) verified the identification of these specimens. Although torrential rains fell during the week in July, 1955, that I spent at Playa Azul near the mouth of the Río Balsas, the distinctive voice of _Rhinophrynus_ was not heard. Elsewhere on the Pacific coast of México adult _Rhinophrynus_ have been reported only from Tehuantepec and a few localities on the coastal lowlands of Chiapas. Taylor (1942b:37) found on the coast of Guerrero a tadpole that was referred to the genus _Rhinophrynus_ by Orton (1943). In the summer of 1960 adults of _Rhinophrynus_ were collected near Acapulco, Guerrero (Fouquette, _in litt._). These recent collections verify the existence of the species along the Pacific lowlands of México at least as far north as Michoacán. ~Scaphiopus hammondi multiplicatus~ Cope _Scaphiopus multiplicatus_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 15:52, June 8, 1863.--Valley of México. _Scaphiopus hammondi multiplicatus_, Kellogg, Bull. U. S. Natl. Mus., 160:22, March 31, 1932. Angahuan (5); Cuitzeo (4); Cuseño Station (2); Jiquilpan (9); Morelia (7); Pátzcuaro (3); Quiroga; Tarécuaro; Uruapan (24); Zacapu. This small toad has been found at elevations between 1500 and 2500 meters on the Mexican Plateau and associated mountain ranges; it occurs in mesquite-grassland and in pine forests. Calling males and females laden with eggs have been collected in the rainy season in the months of July and August. The call is a medium-pitched snore. In living individuals the dorsal ground color varies from pale brown to gray with dark brown or olive-brown markings. In many individuals the tips of the small dorsal pustules are red. ~Bufo coccifer~ Cope _Bufo coccifer_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 18:130, 1866--Arriba, Costa Rica. Apatzingán (27); Lombardia; Nueva Italia (5). In life the dorsal color pattern consists of a yellowish tan ground color with dark brown spots; the middorsal stripe is deep yellow or cream color. The venter is a dusty cream color, and the iris is pale gold. Males have dark brown horny nuptial tuberosities on the thumb. The following measurements are of 21 males and four females, respectively: snout-vent length, 43.5-51.7 (48.1), 55.6-62.6 (59.1); tibia length, 16.6-18.8 (17.6), 18.8-20.3 (19.3); head width, 16.7-19.7 (18.4), 20.6-22.2 (21.4); head length, 13.8-16.6 (14.8), 16.5-18.2 (17.3). The specimens from the Tepalcatepec Valley differ slightly from specimens from southeastern México and Central America. Those from Michoacán have low and narrow cranial crests; in about one-half of the specimens the occipital crest exists only as a row of tubercles, and in some the postorbital and suborbital crests are barely discernible. Specimens from the southern part of the range, Costa Rica and Nicaragua, have much higher and thicker cranial crests; in these the occipital crest is well defined and extends posteriorly to a point back of the anterior edge of the parotid gland; the postorbital and suborbital crests are well marked. Of 48 specimens from Esquipulas, Guatemala, all have high crests, but these are not so well developed as in ten specimens from Matagalpa, Nicaragua, and three from various localities in Costa Rica. Six specimens from Tehuantepec, Oaxaca, have cranial crests that are lower than those in specimens from Guatemala. In three of the specimens from Tehuantepec the occipital crests are reduced to a series of tubercles. Of six specimens from Agua del Obispo, Guerrero, four have poorly developed occipital crests. These observations suggest the presence of a cline in the development of the cranial crests; specimens have higher crests in the southern part of the range than in the northern part. In México _Bufo coccifer_ has been collected only in semi-xeric habitats, but to the south, from Guatemala to Costa Rica, it has been found in more upland and humid habitats. Southern specimens are darker than those from the north, a possible correlation with the differences in habitat. These toads probably range throughout the Tepalcatepec Valley, but they are unknown from the coast of Michoacán. Breeding choruses were found after heavy rains on June 24, 1955, and on August 2, 1956. The first was in a muddy ditch; the second was in a flooded grassy field. The call is a high-pitched, but not loud, "whirrr." Males were calling from the edge of the water or from clumps of grass in the water. Clasping pairs were in the water; amplexus is axillary. ~Bufo compactilis compactilis~ Wiegmann _Bufo compactilis_ Wiegmann, Isis von Oken, 26:661, 1833.--México. Type locality restricted to Xochimilco, Distrito Federal, México, by Smith and Taylor (1950a:330). _Bufo compactilis compactilis_, Smith, Herpetologica, 4:7, September 17, 1947. Cuitzeo (2); Emiliano Zapata (20); Jiquilpan (5); La Palma (5); Morelia; Tupátaro. The southwestern terminus of the range of this species is on the Mexican Plateau in Michoacán. All specimens from the state have spotted venters. In living toads the dorsal ground color was gray or grayish tan with olive green spots. The vocal sac was brownish gray; the iris was a bright golden color. On June 11, 1958, many individuals were calling from shallow water in a flooded field at Emiliano Zapata. The call is a slow trill, in which the individual notes are discernible. ~Bufo marinus~ (Linnaeus) _Rana marina_ Linnaeus, Systema naturae, ed. 10, 1:211, 1758.--America. _Bufo horribilis_ Wiegmann, Isis von Oken, 26:654, 1833.--Misantla and Veracruz, Veracruz, México. Taylor and Smith, Proc. U. S. Natl. Mus., 95:551, January 30, 1945. _Bufo angustipes_ Taylor and Smith, Proc. U. S. Natl. Mus., 95:553, January 30, 1945.--La Esperanza, Chiapas, México. Aguililla; Apatzingán (3); Barranca de Bejuco; Capirio; Charapendo; Chichihuas; Coahuayana (2); Coalcomán (7); Cofradía (2); 25 km. S of Cuatro Caminos; El Sabino (10); Huahua, La Playa (13); Ojos de Agua de San Telmo; Ostula; Playa Azul (2); Pómaro (2). This large toad is characteristically found in areas supporting tropical scrub forest to elevations of about 1000 meters. The species is much more abundant than the numbers listed above suggest. In the dry season individuals have been observed in patios, along streams, and by irrigation ditches. In the rainy season the loud, rattling call of the males is heard at night throughout the Tepalcatepec Valley and the coastal lowlands. Taylor and Smith (1945:552) revived Wiegmann's _Bufo horribilis_ for the large toads of México that are here referred to _B. marinus_. Their action was based upon the supposition that the "species _marinus_" is composite. Although probably true, this supposition has yet to be proved. Until the large, and apparently related, species of _Bufo_ inhabiting tropical America have been studied systematically as a unit, the recognition of segments of the population as either species or subspecies is meaningless. Taylor and Smith (op. cit.:553) based the description of a new species, _Bufo angustipes_, on one rather emaciated, formalin-hardened female from La Esperanza, Chiapas. The type (USNM 116513), when compared with numerous specimens of _Bufo marinus_ from throughout the range of the species in México and northern Central America, displays no combination of characters to set it off from the others. Therefore, I suggest that _Bufo horribilis_ Wiegmann and _Bufo angustipes_ Taylor and Smith be placed in the synonymy of _Bufo marinus_ (Linnaeus) until future systematic study of the genus and this species in particular establishes the existence of recognizable taxa. ~Bufo marmoreus~ Wiegmann _Bufo marmoreus_ Wiegmann, Isis von Oken, 26:66, 1833.--Veracruz, Veracruz, México. Barranca de Bejuco; Coahuayana (11); El Diezmo (2); La Placita (9); La Orilla (12); Motín del Oro; Ostula (9); Playa Azul (5); Pómaro (15); Salitre de Estopilas; San Pedro Naranjestila. In Michoacán this species is confined to elevations of less than 1000 meters on the coast and foothills of the Sierra de Coalcomán. In this region in the months of June and July, breeding congregations have been found in temporary pools and along streams. Smith and Taylor (1948:39), in their key to the Mexican species of _Bufo_, placed emphasis on the nature of the supraorbital and postorbital crests (whether they form a curve or a sharp angle) in distinguishing _Bufo marmoreus_ from _Bufo perplexus_. In the original description of _perplexus_, Taylor (1943a:347) characterized the species as follows: supraorbital and postorbital crests forming a sharp angle, instead of a curve as in _marmoreus_; supratympanic crest smaller than in _marmoreus_; diagonal lateral stripe lacking in females; concentration of dorsal tubercles as found in _marmoreus_ lacking in males. The discovery of specimens in which the crests form a curve and others in which the crests form an angle in both the Tepalcatepec Valley and in the coastal lowlands prompted an investigation of these characters and others throughout the ranges of the species. An examination of 410 specimens has resulted in the following conclusions. TABLE 1.--VARIATION IN THE SHAPE OF THE SUPRAORBITAL AND POSTORBITAL CRANIAL CRESTS IN BUFO MARMOREUS AND B. PERPLEXUS. +------------------------+---+-----------+------------+----------+ |LOCALITY | N | Curved |Intermediate| Angular | +------------------------+---+-----------+------------+----------+ |Tepalcatepec Valley | 50| 10 (20.0%)| 17 (34.0%) |23 (46.0%)| +------------------------+---+-----------+------------+----------+ |Morelos | 12| 2 (16.6%)| 5 (41.7%) | 5 (41.7%)| +------------------------+---+-----------+------------+----------+ |Izúcar, Puebla | 4| 2 (50.0%)| 0 (0.0%) | 2 (50.0%)| +------------------------+---+-----------+------------+----------+ |Southern Sinaloa | 1| 1(100.0%)| 0 (0.0%) | 0 (0.0%)| +------------------------+---+-----------+------------+----------+ |Puerto Vallarta, Jalisco| 2| 2(100.0%)| 0 (0.0%) | 0 (0.0%)| +------------------------+---+-----------+------------+----------+ |Colima | 45| 25 (55.0%)| 18 (40.0%) | 2 (5.0%)| +------------------------+---+-----------+------------+----------+ |Coast of Michoacán | 55| 35 (63.6%)| 17 (30.9%) | 3 (5.5%)| +------------------------+---+-----------+------------+----------+ |Acapulco, Guerrero | 7| 7(100.0%)| 0 (0.0%) | 0 (0.0%)| +------------------------+---+-----------+------------+----------+ |Chilpancingo, Guerrero | 10| 1 (10.0%)| 4 (40.0%) | 5 (50.0%)| +------------------------+---+-----------+------------+----------+ |Pochutla, Oaxaca | 13| 6 (46.2%)| 6 (46.2%) | 1 (7.6%)| +------------------------+---+-----------+------------+----------+ |Tehuantepec, Oaxaca |177| 81 (45.8%)| 67 (37.8%) |29 (16.4%)| +------------------------+---+-----------+------------+----------+ |Tonolá, Chiapas | 1| 0 (0.0%)| 0 (0.0%) | 1(100.0%)| +------------------------+---+-----------+------------+----------+ |Veracruz | 33| 26 (78.8%)| 6 (18.2%) | 1 (3.0%)| +------------------------+---+-----------+------------+----------+ | Total |410|198 (48.3%)|140 (34.2%) |72 (17.5%)| +------------------------+---+-----------+------------+----------+ 1. Although the highest percentage of individuals having the supraorbital and postorbital crests forming a sharp angle is from localities in the Balsas-Tepalcatepec Basin, numerous individuals from throughout the range of _marmoreus_ have the crests forming an angle (Table 1). 2. In all samples of ten or more specimens, some toads have the supraorbital and postorbital crests forming a sharp angle, some have the crests forming a curve, and some have an intermediate condition. 3. The relative size of the supratympanic crest is highly variable in all samples examined. [Illustration: FIG. 3. Adult male of _Bufo perplexus_ from Apatzingán, Michoacán. × 1.5.] [Illustration: FIG. 4. Adult male of _Bufo marmoreus_ from Pómaro, Michoacán. × 1.5.] [Illustration: PLATE 1 Hatchling of _Pseudoeurycea belli_ from San Juan de Parangaricutiro, Michoacán. × 8.] [Illustration: PLATE 2 FIG. 1. Nest and eggs of _Pseudoeurycea belli_ beneath a rock at San Juan de Parangaricutiro. Approx. natural size. FIG. 2. Multiple egg clutches of _Phyllomedusa dacnicolor_ from Coalcomán, Michoacán. 1/3 ×. [Illustration: PLATE 3 FIG. 1. Adult male of _Tomodactylus angustidigitorum_ from Paracho, Michoacán. × 4. FIG. 2. Adult male of _Tomodactylus fuscus_ from Los Cantiles, Michoacán. ×4. [Illustration: PLATE 4 FIG. 1. Adult male of _Tomodactylus nitidus_ nitidus from Tuxpan, Michoacán. ×. FIG. 2. Adult male of _Tomodactylus nitidus orarius_ from Tecolapa, Colima. × 4.] [Illustration: PLATE 5 FIG. 1. Adult male of _Tomodactylus nitidus_ petersi from Apatzingán, Michoacán. × 4. Fig. 2. Adult male of _Tomodactylus rufescens_ from Dos Aguas, Michoacán. × 4.] [Illustration: PLATE 6 FIG. 1. Adult male of _Hypopachus caprimimus_ from Tuxpan, Michoacán. × 2-1/2. FIG. 2. Adult male of _Hypopachus oxyrrhinus ovis_ from Tangamandapio, Michoacán. × 3.] 4. A distinct, pale-colored, diagonal lateral stripe is found in females only from localities outside of the Balsas-Tepalcatepec Basin; females from the basin have a spotted dorsum. 5. Males from the Balsas-Tepalcatepec Basin usually have a broad middorsal line that is yellow or pale tan; those from outside the basin have either a narrow middorsal line or none. 6. Males from the Balsas-Tepalcatepec Basin have low, scattered dorsal tubercles (Fig. 3); males from outside the basin have a concentration of tubercles in a broad band on the back (Fig. 4). Therefore the nature of the cranial crests is of little value in separating two populations, but the color pattern of the females and the nature of the dorsal tubercles of the males do show distinct differences. Furthermore, certain differences in size and proportion are evident; _Bufo marmoreus_ is a slightly larger toad and has a relatively longer tibia and longer head than _perplexus_ (Table 2). TABLE 2.--COMPARISON OF CERTAIN MEASUREMENTS AND PROPORTIONS IN BUFO MARMOREUS AND B. PERPLEXUS. (MEANS ARE GIVEN IN PARENTHESES BELOW THE RANGES.) +-------------------+------------+--+----------+------------+-----------+ | | | | |Tibia length|Head length| | Species | Sex | N|Snout-vent+------------+-----------+ | | | | length | Snout-vent |Snout-vent | | | | | | length | length | +-------------------+------------+--+----------+------------+-----------+ | _B. marmoreus_ | Male |15|61.5-72.5 | 35.9-41.6 | 28.3-33.3 | | | | | (65.2) | (39.0) | (31.6) | +-------------------+------------+--+----------+------------+-----------+ | _B. perplexus_ | Male |20|50.0-59.0 | 33.7-38.1 | 26.4-31.1 | | | | | (54.9) | (36.4) | (29.5) | +-------------------+------------+--+----------+------------+-----------+ | _B. marmoreus_ | Female | 7|68.0-76.0 | 33.0-36.8 | 26.8-32.6 | | | | | (70.7) | (34.7) | (29.6) | +-------------------+------------+--+----------+------------+-----------+ | _B. perplexus_ |Female | 6|64.1-69.8 | 32.4-36.9 | 25.1-29.0 | | | | | (66.8) | (35.5) | (27.5) | +-------------------+------------+--+----------+------------+-----------+ Taylor (1943a:347) described _Bufo perplexus_ from Mexcala on the Río Balsas in Guerrero. Among the many paratypes are specimens from Tonolá, Chiapas, and Tehuantepec, Oaxaca. These apparently were referred to _perplexus_ solely on the nature of the cranial crests. All of the specimens examined during the course of the present study from the lowlands of Veracruz and from the Pacific lowlands from Sinaloa southward to Chiapas are referable to _Bufo marmoreus_; those from the Balsas-Tepalcatepec Basin are referable to _Bufo perplexus_, as defined above. Ten specimens from Chilpancingo, Guerrero (UMMZ 115352), do not readily fit either species. Perhaps there is gene exchange between the inland and coastal populations through the relatively low pass at Chilpancingo, at the mouth of the Río Balsas, and near the convergent headwaters of the Río Coahuayana and Río Tepalcatepec in southern Jalisco. If this can be demonstrated, then _Bufo perplexus_ would have to be considered as a subspecies of _Bufo marmoreus_, instead of an allopatric species. ~Bufo perplexus~ Taylor _Bufo perplexus_ Taylor, Univ. Kansas Sci. Bull., 29:347, October 15, 1943.--Balsas River near Mexcala, Guerrero, México. Aguililla (2); Apatzingán (42); Buena Vista (5); Capirio (3); La Playa (25); Lombardia (6); Nueva Italia (9); Río Cancita, 14 km. E of Apatzingán; Río Tepalcatepec, 27 km. S of Apatzingán; San Salvador (4); Tzitzio; Volcán Jorullo. ~Bufo occidentalis~ Camerano _Bufo occidentalis_ Camerano, Atti R. Accad. Sci. Torino, 14:887, December 31, 1878.--México. Type locality restricted to Guanajuato, Guanajuato, México, by Smith and Taylor (1950a:330). Firschein, Copeia, no. 3:220, September 15, 1950. _Bufo símus_, Smith and Taylor, Bull. U. S. Natl. Mus., 194:42, 1948. Barranca Seca (32); Cerro de Barolosa (4); Cerro Tancítaro, 3 km. E of Apo (2); Cerro Tancítaro, 19 km. E. of Apo (10); Charapendo; Coalcomán (7); Dos Aguas (4); Jacona, Jaramillo (2); Las Tecatas; Los Reyes (181); Tancítaro (10); Uruapan (3). This toad is an inhabitant of pine and oak forests between 900 and 2400 meters. Near Charapendo on the slopes of the Sierra de los Tarascos and at Coalcomán it apparently reaches its lowest altitudinal limits. At both of these localities the pine-oak forest is replaced by arid tropical scrub forest on the lower slopes. Twenty-four tadpoles were collected on May 3 in a quiet section of a fast stream near Barranca Seca. The tadpoles have a robust body, broadest about two-thirds the distance from the snout to the posterior edge of the body, half again as broad as deep. Eyes dorsolateral; nostrils dorsal, somewhat directed forward, and about three-fifths the distance from the tip of the snout to the eye; spiracle sinistral and lateral, located at about midbody; anus median; tail long and slender; tail-musculature extends nearly to tip of tail; depth of tail-musculature at mid-length about one-third total depth of tail; dorsal tail-fin not extending onto body (Fig. 5); average body length of ten tadpoles having small hind limb buds, 14.4 mm.; average tail length, 22.0 mm. Mouth ventral, nearly terminal, about one-third as wide as widest part of body; anterior lip has no papillae; lower lip bordered by two rows of papillae and lateral lips by one row of papillae; beaks moderately well developed, the upper forming a broad arch and finely denticulate; tooth rows 2/3, the upper rows extending to the edge of the lips, subequal in length, and slightly longer than lower rows, which also are subequal in length; inner upper tooth row broken medially; inner lower tooth row sometimes broken (Fig. 6). The body is black dorsally and laterally, and bluish gray ventrally; the tail musculature is brown and stippled with darker brown. The fins are transparent and stippled with brown, the stippling being most pronounced on the posterior two-thirds of the upper tail-fin. [Illustration: FIG. 5. Tadpole of _Bufo occidentalis_ (UMMZ 94269) from Barranca Seca, Michoacán. × 3.] [Illustration: FIG. 6. Mouthparts of larval _Bufo occidentalis_ (UMMZ 94269) from Barranca Seca, Michoacán. × 20.] Forty recently metamorphosed individuals average 18.9 mm. in snout-vent length. The relationships of this toad seem to be with _Bufo bocourti_ Brocchi, an inhabitant of pine and oak forests in the uplands of Chiapas and Guatemala. In _Bufo occidentalis_ the tympanum usually is indistinct and sometimes completely covered, and it is absent in _bocourti_. _Bufo occidentalis_ has a broader interorbital area and relatively shorter and more rounded parotid glands than _bocourti_. The tadpoles of the two species are nearly identical (see Stuart, 1943:12). ~Leptodactylus labialis~ (Cope) _Cystignathus labialis_ Cope, Proc. Amer. Philos. Soc., 17:90, 1877.--No type locality designated; type locality restricted to Potrero Viejo, Veracruz, México, by Smith and Taylor (1950a:350). _Leptodactylus labialis_, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881. Apatzingán (26); Capirio (5); Cofradía (9); El Sabino (4); Lombardia; Río Tepalcatepec, 27 km. S of Apatzingán (2). In the Tepalcatepec Valley this frog reaches the northernmost known limit of its range in western México. Although the species is abundant in the valley, it apparently is absent from the coastal lowlands. In the Tepalcatepec Valley _Leptodactylus melanonotus_ seems to be more abundant than _labialis_. In the rainy season both species have been heard calling from the same ponds and flooded fields. There are only slight differences in size between the sexes; measurements of 20 males and eight females are, respectively: snout-vent length, 32.3-39.5 (35.1), 34.1-39.2 (37.2); tibia length, 14.3-17.0 (15.4), 14.9-16.8 (15.8); head width, 11.0-13.6 (12.0), 12.2-13.2 (12.6); head length, 12.8-15.1 (13.3), 12.8-14.6 (13.7). ~Leptodactylus melanonotus~ (Hallowell) _Cystignathus melanonotus_ Hallowell, Proc. Acad. Nat. Sci. Philadelphia, 12:485, 1861.--Nicaragua. Type locality restricted to Recero, Nicaragua, by Smith and Taylor (1950a:320). _Leptodactylus melanonotus_, Brocchi, Mission Scientifique au Mexique et dans l'Amerique Centrale, pt. 3, sec. 2, livr. 1:20, 1881. Apatzingán (103); Capirio; Charapendo (7); Coahuayana; Cofradía (10); El Sabino (21); La Playa (3); Lombardia (5); Maruata; Nueva Italia (7); Ostula (9); Playa Azul (11); Río Marquez, 10 km. S of Lombardia; Río Marquez, 13 km. SE of Nueva Italia (6); Río Tepalcatepec, 27 km. S of Apatzingán. This species is widespread in the lowlands of the state; it has been collected up to elevations of 1050 meters in the Tepalcatepec Valley. In the dry season individuals were discovered beneath rocks along streams and in damp arroyos; in the rainy season they were found wherever there was water. Males were heard calling from flooded fields, ditches, rocky streams, and small puddles. The call is a series of individual notes: "woink, woink, woink." Adult males are noticeably smaller than females; measurements for 20 males and ten females from Apatzingán are, respectively: snout-vent length, 29.6-34.6 (32.3), 36.3-44.1 (40.8); tibia length, 12.6-15.1 (14.0), 16.5-19.0 (17.8); head width, 10.8-11.9 (11.3), 12.6-14.8 (13.7); head length, 11.2-13.2 (11.9), 13.1-14.8 (14.0). Brownish yellow ventral glands are present in some juveniles and in some adults collected in the dry season as well as in the rainy season. ~Leptodactylus occidentalis~ Taylor _Leptodactylus occidentalis_ Taylor, Trans. Kansas Acad. Sci., 39:349, 1937.--Tepic, Nayarit, México. Five km. W of Tangamandapio. On the night of June 11, 1958, this species was calling from a hyacinth-choked ditch. Although numerous individuals were heard, only one specimen was obtained. The frogs were calling from the tangled mat of hyacinths along with _Hyla eximia_, _Hypopachus oxyrrhinus ovis_, and _Rana pipiens_. Taylor (1936a:352) characterized this species as follows: "The narrow head, small maximum size (38 mm. for females, 33 mm. for males), the character of the postaxillary and postfemoral glands, the narrower groups of vomerine teeth, clearly distinguish this western Mexican form from the more robust, larger _melanonotus_ to the south. The call is likewise fainter and different in quality." Concerning the glands, Taylor (_loc. cit._) remarked: "There is a possibility that the horny excrescence covering the glands may appear only during the breeding season. This character is quite as strongly marked in females as in males." Bogert and Oliver (1945:324) concluded that the population of _Leptodactylus_ in northwestern México could not be distinguished from _melanonotus_ in other parts of the country and thus synonymized _Leptodactylus occidentalis_ with _melanonotus_. Bogert and Oliver (op. cit.: 324) stated that the extent as well as the presence or absence of ventral glands was highly variable in all samples examined by them. Upon seeing numerous living individuals of _Leptodactylus melanonotus_ from many parts of its range in México and individuals of the population of _Leptodactylus_ in northwestern México (Nayarit and Sinaloa), I was immediately impressed not so much by the differences in the development of the ventral glands, but by the color of the glands. The differences in color are apparent in freshly preserved specimens. With the exception of _Leptodactylus_ from northwestern México, specimens of _melanonotus_ from throughout México and northern Central America have yellow or yellowish brown glands. Specimens from northwestern México have black or brownish black glands that are conspicuously darker than those found in _melanonotus_. Examination of 653 preserved specimens of _Leptodactylus melanonotus_ from México and Guatemala has failed to reveal specimens with black ventral glands, like those found in specimens from northwestern México, to which the name _Leptodactylus occidentalis_ has been applied. Furthermore, in _melanonotus_ the glands are less distinct and more extensive than in _occidentalis_; in the latter species glands are absent from the throat and midventral area, where they often are present in _melanonotus_ (Fig. 7). In some individuals of both species collected in the dry season and in some collected in the rainy (breeding) season the glands are absent; the development of these glands, therefore, does not seem to be correlated with breeding. Likewise, the glands are present or absent in either sex, and often as not they are present in juveniles. Presence of the glands, therefore, cannot be correlated either with sexual or ontogenetic development. Since the glands are found in individuals from all parts of the range, it is unlikely that there is a correlation between the development of the glands and the environment. [Illustration: FIG. 7. Diagrammatic view of ventral surfaces of _Leptodactylus melanonotus_ (A) and _Leptodactylus occidentalis_ (B), showing usual position and size of glandular areas. Approx. natural size.] Aside from the differences in the ventral glands, the call is different in the two populations. The call of _Leptodactylus occidentalis_ is a rather harsh "wack, wack, wack" as contrasted with the more nasal "woink, woink, woink" of _melanonotus_. Sound spectrographs are needed to analyze the differences in calls. None of the specimens of _occidentalis_ examined approaches in size the largest individuals of _melanonotus_; possibly the size of the frogs is another valid character for separating the species. On the basis of the above data it is evident that the frogs in northwestern México show certain characters that distinguish them from _Leptodactylus melanonotus_, as it is known throughout the rest of México. It is not known for certain that _melanonotus_ and _occidentalis_ are sympatric. Several series of old, poorly preserved specimens from Nayarit and Sinaloa cannot be placed in either species, for none has visible ventral glands. _Leptodactylus melanonotus_ is known from Acaponeta, Nayarit (AMNH 43913-25), and the following localities in Jalisco: Barro de Navidad (UMMZ 118098), La Concepción (UMMZ 113081), La Resolana (UMMZ 102104), and Tenachitlán (UMMZ 113045-6). Records for _Leptodactylus occidentalis_ are: Álamos, Sonora (AMNH 51356-65); Culiacán (AMNH 49511-9), Chele (UMMZ 110914), and Rosario (UMMZ 113062) in Sinaloa; Ixtlán del Río (UMMZ 102108), San Blas (UMMZ 112814, 112994, 110892, 115543), and Tepic (UMMZ 115544) in Nayarit; Ameca (UMMZ 102106-7) and La Cofradía on the south shore of Lago de Chapala (UMMZ 102105) in Jalisco; and Tangamandapio, Michoacán (UMMZ 119145). From these scattered records it appears that _Leptodactylus occidentalis_ in the southern part of its range stays in the uplands, whereas _melanonotus_ is confined to the lowlands. ~Microbatrachylus hobartsmithi~ (Taylor) _Eleutherodactylus hobartsmithi_ Taylor, Trans. Kansas Acad. Sci., 39:355, 1937.--Uruapan, Michoacán, México. _Microbatrachylus hobartsmithi_ Taylor, Univ. Kansas Sci. Bull., 26:501, November 27, 1940. Cascada Tzararacua (6); 21 km. W of Ciudad Hidalgo; 29 km. E of Morelia; Puerto Hondo; San José de la Cumbre (13); Uruapan (2); Zitácuaro. Of six specimens from Cascada Tzararacua, five are colored like typical _M. hobartsmithi_, having the anterior and posterior surfaces of the thighs and the upper arms pale pink in life and a grayish brown dorsum in preservative. The other specimen (UMMZ 94231) has in preservative a dark brown dorsolateral line on each side enclosing a pale tan area that extends from the snout to the vent. One specimen from 29 kilometers east of Morelia (UIMNH 40338) and 13 specimens from San José de la Cumbre (UMMZ 102111) do not have the prominent tarsal tubercles characteristic of _M. hobartsmithi_. Also, in these fourteen specimens the palmar tubercles are larger, and the dark anal patch more distinct, than in typical _M. hobartsmithi_. Possibly these specimens, which are from the high mountains in the eastern part of Michoacán, represent another species of _Microbatrachylus_. However, Taylor (1940d:501) reported a series of _M. hobartsmithi_ from the mountains 10 miles west of Villa Victoria in the western part of the state of México. The largest specimen from Michoacán is a gravid female (UIMNH 16104) having a snout-vent length of 23.5 mm. _Microbatrachylus hobartsmithi_ has been found in rocky ravines along streams in the Cordillera Volcánica and the southwestern escarpment of these mountains at elevations from 1450 to 2750 meters. ~Microbatrachylus pygmaeus~ (Taylor) _Eleutherodactylus pygmaeus_ Taylor, Trans. Kansas Acad. Sci., 39:352, 1937.--1 mile north of Rodriguez Clara, Veracruz, México. _Microbatrachylus pygmaeus_ Taylor, Univ. Kansas Sci. Bull., 26:500, November 27, 1940. _Microbatrachylus albolabris_ Taylor, Univ. Kansas Sci. Bull., 26:502, November 27, 1940.--2 miles west of Córdoba, Veracruz, México. _Microbatrachylus minimus_ Taylor, Univ. Kansas Sci. Bull., 26:507, November 27, 1940.--Agua del Obispo, Guerrero, México. _Microbatrachylus imitator_ Taylor, Univ. Kansas Sci. Bull., 28:70, May 15, 1942.--La Esperanza, Chiapas, México. Arteaga (328). This large series (UMMZ 119247-8) was collected on June 22 and 23, 1958, before the onset of the heavy summer rains. The frogs were found in a shaded ravine at the north edge of Arteaga; they were obtained during the day, at which time they were actively moving about in the leaf litter along a small stream. These frogs are all referred to _M. pygmaeus_, because this is the earliest name available for frogs showing the variation in characteristics displayed by this large series. The characters used by Taylor (1936a, 1940d, 1941a, and 1942b) and Smith and Taylor (1948) to distinguish the various species of _Microbatrachylus_ include color pattern, relative length of the hind limb, presence and position of dorsal dermal folds or pustules, relative size of inner and outer metatarsal tubercles, and the number of palmar tubercles. All specimens from Arteaga have two palmar tubercles; the inner and outer metatarsal tubercles are subequal in size. Furthermore, aside from sexual difference, there is little variation in the relative length of the hind limbs (Table 3). However, many color patterns do exist in the series; each of these color patterns is described below. TABLE 3.--SNOUT-VENT LENGTH EXPRESSED AS A PERCENTAGE OF TIBIA LENGTH IN ANIMALS OF SIX COLOR PATTERNS OF MICROBATRACHYLUS PYGMAEUS. (LETTERS REFER TO THE VARIANTS HAVING THE COLOR PATTERN DISCUSSED IMMEDIATELY BELOW) +------------+-----------+---------+---------+----+--------+ | | | Number | Range | | Twice | | Color | Sex | of | of |Mean|standard| |Pattern | |specimens|variation| | error | | | | | | |of mean | +------------+-----------+---------+---------+----+--------+ | A | Male | 25 |51.4-57.5|55.2| 3.34 | | | Female | 25 |49.3-54.9|51.6| 3.12 | | B | Male | 20 |51.0-57.1|55.4| 2.44 | | | Female | 21 |47.3-54.9|51.2| 3.52 | | C | Male | 6 |54.5-56.2|55.2| .... | | | Female | 6 |50.0-52.9|51.6| .... | | D | Male | 17 |52.9-58.2|55.4| 2.64 | | | Female | 14 |48.5-56.6|52.1| 4.16 | | E | Male | 10 |50.9-56.9|55.1| 3.40 | | | Female | 7 |49.6-54.5|51.6| .... | | F | Female | 2 |51.9-52.6|52.3| .... | +------------+-----------+---------+---------+----+--------+ A.--225 specimens: Dorsum mottled brown and cream, usually with a dark spot between the eyes and one or two dark V-shaped marks with the apex anteriorly on the back; 55 of these have a narrow cream-colored line from the tip of the snout to the vent and thence onto the posterior surfaces of the thighs. All are pustulate above; in most specimens the pustules form no pattern, but in some they tend to form a V in the scapular region. B.--41 specimens: Dorsum pale tan or cream-color with brown mottling on flanks; a brown interorbital bar and a brown chevron in scapular region. Dorsum irregularly pustulate; in some specimens the pustules tend to form a V in the scapular region. C.--12 specimens: Dorsum colored like "A", but having a broad yellow stripe narrowly bordered by black from the tip of the snout to the vent; in some specimens there is a narrow yellow stripe on the posterior surfaces of the thighs. The dorsum is irregularly pustulate. D.--31 specimens: Dorsum variably streaked with cream-color or pale tan and brown; usually a broad cream-colored stripe from eyelid to groin bordered laterally by a somewhat narrower brown stripe; middorsal area cream-color and separated from dorsolateral cream-colored stripe by a brown stripe, or middorsal area brown with a cream-colored or yellow, narrow stripe from tip of snout to vent; a dark stripe from tympanum to flank; dorsal surfaces of heels creamy white to pale orange; anal patch brown. A dermal ridge from posterior edge of eyelid to rump; another ridge extends posteromedially from the eyelid; scattered pustules on the dorsum in some specimens. E.--17 specimens: A narrow dark stripe from snout, through nostril and eye, over tympanum, to vent, enclosing a unicolor dorsum (reddish tan to yellowish tan in life); heels pale tan or yellow above; anal patch black. A faint dermal ridge from posterior edge of eyelid to rump, or part way to rump. F.--2 specimens: Mottled brown and cream-color above; upper lips and upper arms white. A dermal fold from posterior edge of eyelid to rump; scattered pustules on dorsum. Some of these color variants are assignable to names proposed by Taylor: "A" and "B" undoubtedly are _M. pygmaeus_ (Taylor, 1936a); "C" probably is _M. pygmaeus_; "D" is referable to _M. minimus_ (Taylor, 1940d) in most characteristics, although the coloration is more nearly like that of _M. lineatissimus_ (Taylor, 1941a), a larger species characterized by a relatively long hind limb; "E" apparently is _M. imitator_ (Taylor, 1942b); "F" is _M. albolabris_ (Taylor, 1940d). Examination of series of these frogs from other parts of México shows a similar composition of color variants. Of 78 specimens from the Río Sarabia and the village of Sarabia in Oaxaca (UMMZ 115428-37), 57 are "A," six are "D," three are "E," and 12 are "F"; of 22 specimens from Teapa, Tabasco (UMMZ 113829), 11 are "A," five are "D," two are "E," and four are "F"; of 33 specimens from Potrero Viejo, Veracruz (USNM 115447-58, 115461-71, 116840-2, 116864-70), ten are "A," 13 are "E," and ten are "F"; of 31 specimens from La Esperanza, Chiapas (USNM 115477-9, 116827-39, 116849-63), 28 are "A" and four are "F." It is highly doubtful if these color variants are actually distinct species. Goin (1950 and 1954) in his studies of inheritance of color pattern in West Indian species of the genus _Eleutherodactylus_ has shown that similar color pattern variants come from the same clutch of eggs; furthermore, Goin has worked out the genetic ratios of certain of these variants. Heathwole (_in litt._) obtained "normal" specimens and individuals having a broad middorsal stripe ("C" in figure 9) from a clutch of eggs of _Eleutherodactylus gollmeri_. The presence of a broad middorsal yellow stripe is common in _Eleutherodactylus rugulosus_. Perhaps the most interesting aspect of variability in color pattern in Mexican eleutherodactylids is the parallelism between members of the _Eleutherodactylus rhodopis_-group and some members of _Microbatrachylus_. In the former group there are white-lipped individuals (_Eleutherodactylus beatae_ Boulenger), individuals having a unicolor reddish or yellowish dorsum (_E. dorsoconcolor_ Taylor), and individuals having a dorsal pattern of irregular longitudinal brown and cream-colored streaks (_E. venustus_ Günther). In the humid forests of southern Veracruz, northern Oaxaca, and Chiapas members of both groups occur sympatrically. A proper understanding of the evolutionary significance of these variants in the two groups, as well as proper allocation of the presently recognized species, must await experimental evidence based on studies of the inheritance of color pattern. Nevertheless, at present it is apparent that certain characters, especially the nature of the dermal folds and pustules, and the color pattern, are of little taxonomic value in distinguishing "species" of _Microbatrachylus_. The data derived from a study of the large series from Arteaga, together with that from the other series examined, suggests that _Microbatrachylus albolabris_, _imitator_, _minimus_, and _pygmaeus_ are morphotypes of one species. Of these names, _pygmaeus_ is the oldest. Consequently _Microbatrachylus pygmaeus_ has been used here for the series from Arteaga. Although _Microbatrachylus hobartsmithi_, a species distinguished from all of the above by the presence of tubercles on the outer edge of the tarsus, is known from Michoacán northward into Nayarit, _Microbatrachylus pygmaeus_ previously has not been known north of Guerrero, where it occurs in habitats similar to that in which it was collected at Arteaga. ~Eleutherodactylus augusti cactorum~ Taylor _Eleutherodactylus cactorum_ Taylor, Univ. Kansas Sci. Bull., 25:391, July 10, 1939.--20 miles northwest of Tehuacán, Puebla, México. _Eleutherodactylus augusti cactorum_, Zweifel, Amer. Mus. Novitates, 1813:20, December 23, 1956. Cherán; Coalcomán; Uruapan. The few specimens indicate that this species occurs at moderate to high elevations in the state. The specimens from Cherán and Uruapan were obtained in pine forests; the specimen from Coalcomán was found on a rocky hillside covered with dense forest and located about 100 meters below the lower limits of the pine forest in the area. A specimen from Rancho Reparto (elevation 1850 meters) on the west slope of Cerro Barolosa was lost. The specimen from Coalcomán (UMMZ 104728) is a juvenile having a snout-vent length of 25.0 mm. In life it was tan above, mottled with olive-green. The ventral surfaces were gray; the hind limbs were distinctly barred with yellow and brown, and the lips were barred with yellow and black. ~Eleutherodactylus occidentalis~ Taylor _Eleutherodactylus occidentalis_ Taylor, Proc. Biol. Soc. Washington, 54:91, July 31, 1941.--Hacienda El Florencio, Zacatecas, México. Arteaga (2); Cascada Tzararacua; Coalcomán (2); 19 km. SW of Coire (3); La Placita (7); Los Reyes; Ostula (4); Pómaro (2). The locality records for this species suggest that it is a member of a group of animals, the distribution of which includes the western part of the Mexican Plateau and the Pacific lowlands. In Michoacán this frog has been collected in pine-oak forest at Cascada Tzararacua and at Los Reyes, in arid scrub forest at Arteaga and Coalcomán, and in tropical semi-deciduous forest on the lower Pacific slopes of the Sierra de Coalcomán. On July 5, 1950, James Peters (1954:6) found calling males at La Placita. Most of the specimens are immature; four adult males have snout-vent lengths of 30.9-33.0 (32.2) mm. In all specimens the first finger is noticeably longer than the second; the inner metatarsal tubercle is large, flat, and cream-colored, contrasting with the dark brown sole of the foot. When the hind limbs are adpressed, the heels broadly overlap. Characteristically, a dark line extends from the snout, through the eye, above the tympanum, to a point above the insertion of the forelimb. Usually there is a dark bar behind the tympanum, two dark brown bars from the eye to the mouth and thence onto the lower jaw, and another dark bar on the upper lip between the eye and nostril. One adult from Arteaga, an adult and a juvenile from La Placita, and one juvenile each from Coire, Ostula, and Pómaro, have the lower lip barred with dark brown and white, and have a white stripe extending the length of the upper lip. In life the dorsum varies from dark gray or olive-brown to tan or reddish brown. This species belongs to a group containing two other populations that are currently recognized as species--_calcitrans_, known only from Omiltemi, Guerrero, and _mexicanus_, reported from the mountains of Oaxaca. Another apparently undescribed member of this group has been collected in the mountains of northern Puebla. The locality records indicate that the group inhabits the mountains on the periphery of the Mexican Plateau, except in western México, where _Eleutherodactylus occidentalis_ extends to the Pacific lowlands. ~Eleutherodactylus rugulosus vocalis~ Taylor _Eleutherodactylus vocalis_ Taylor, Univ. Kansas Sci. Bull., 26:401, November 27, 1940.--Hacienda El Sabino, Michoacán, México. Arteaga (10); El Sabino (8); Salitre de Estopilas (3); Tumbiscatio (2); Tzitzio (2). The distributional data on this frog in Michoacán indicate that it inhabits riparian situations in arroyos and canyons in the lower slopes of the Cordillera Volcánica and the Sierra de Coalcomán, where it has been taken at elevations only below 1100 meters. The dorsal color of living individuals from Arteaga varied from dark gray and olive brown to tan and reddish brown. The iris was grayish brown. In contrast, individuals from Agua del Obispo, Guerrero, had pale golden eyes; specimens from Matías Romero, Oaxaca, had gold eyes heavily flecked with gray; and individuals from Volcán San Martin, Veracruz, had bronze eyes. The use of the trinomial here is arbitrary. Frogs of the _Eleutherodactylus rugulosus_ group in México (_rugulosus_, _avocalis_, and _vocalis_) exhibit only slight differences in size, proportions, and coloration (Duellman, 1958c:6). Furthermore, the named populations are allopatric. _Eleutherodactylus rugulosus vocalis_, as defined by Duellman (_loc. cit._), occurs in the foothills of the Sierra Madre Occidental and associated ranges from central Sinaloa southward into Michoacán. ~Tomodactylus angustidigitorum~ Taylor _Tomadactylus angustidigitorum_ Taylor, Univ. Kansas Sci. Bull., 26:494, November 27, 1940.--Quiroga, Michoacán, México. Angahuan (6); Apo; Carapan (21); 19 km. S of Carapan (13); Cerro Tancítaro (12); Cherán; Corupu (14); Cuseño Station (14); Opopeo (3); Paracho (11); Parícutin (2); Pátzcuaro (3); Quiroga (59); San Juan de Parangaricutiro (16); Tancítaro (25); Uruapan (8); Zacapu (11). This species is indigenous to the pine-oak forests on the southern rim of the Mexican Plateau, and has been collected at elevations from 1500 to 2500 meters. Males have been observed to call from rocks, rock fences, clumps of grass, and low bushes; the call is a single "peep." At San Juan de Parangaricutiro numerous specimens were found in the daytime beneath adobe bricks and lava on the volcanic ash derived from Volcán Parícutin; at Paracho individuals were found by day beneath rocks in a pine forest. In most specimens the dorsum is dark reddish brown, and the prominent inguinal glands are cream-color or pale orange (Pl. 3, Fig. 1). Of eight individuals collected at Paracho, one was reddish brown, two were pinkish tan, three were dark brown, and two were black. ~Tomodactylus fuscus~ Davis and Dixon _Tomodactylus fuscus_ Davis and Dixon, Herpetologica, 11:157, July 15, 1955.--1.5 miles southeast of Huitzilac, Morelos, México. Los Cantiles (2); 28 km. E of Morelia. The range of this species includes the Sierra Ajusco in México and Morelos and thence westward to the Serranía Ucareo in Michoacán. The specimen from 28 kilometers east of Morelia was found in an oak forest on a steep hillside at an elevation of 2100 meters. One from Los Cantiles was calling from a steep cliff at an elevation of 2200 meters in pine-oak forest. This specimen (UMMZ 119156) in life had a pale olive-brown dorsum with irregular dark brown mottling and transverse bars on the limbs. The interorbital bar, the upper arms, and the tips of the dorsal pustules were pale orange; the iris was pale grayish gold (Pl. 3, Fig. 2). ~Tomodactylus nitidus nitidus~ (Peters) _Liuperus nitidus_ Peters, Monats. Akad. Wiss. Berlin, p. 878, 1869.--Izúcar de Matamoras, Puebla, México. _Tomodactylus amulae_ Günther, Biologia Centrali-Americana, Reptilia and Batrachia, p. 219, April, 1900.--Amula, Guerrero, México. _Tomodactylus nitidus nitidus_, Dixon, Texas Jour. Sci., 9:385, December, 1957. Copuyo (15); Tuxpan (8); Tzitzio (11). One specimen from Tzitzio (UMMZ 99155) was referred to _Tomodactylus nitidus petersi_ by Dixon (1957:390). A re-examination of this specimen, and examination of ten others from the same locality (UMMZ 121571) reveals that the relatively small size of the tympanum and absence of dense ventral spotting place these specimens closer to _T. nitidus nitidus_ than to _T. nitidus petersi_. The specimens from Tuxpan (UMMZ 114303-4) had in life a gray to olive tan ground color with dark olive-green markings, bright yellow thighs with olive-green transverse bands, yellowish tan shanks with olive-green bars, yellow groin, white inguinal glands with black markings, grayish white belly with scattered brownish black spots in some specimens, and a deep golden iris (Pl. 4, Fig. 1). These specimens were found calling from bushes in a rocky field at an elevation of 1800 meters. The call is a high-pitched "pee-ee-eep." ~Tomodactylus nitidus orarius~ Dixon _Tomodactylus nitidus orarius_ Dixon, Texas Jour. Sci., 9:392, December, 1957.--4.5 miles southwest of Tecolapa, Colima, México. La Placita (3); Pómaro. These specimens, referred to _Tomodactylus petersi_ by Duellman (1954b:5), were included in _T. nitidus orarius_ by Dixon (1957:392). Color notes based on living individuals from Tecolapa, Colima (UMMZ 114312 and 116922), are: gray above mottled with brown; venter dirty white; anterior and posterior surfaces of thighs bright yellow; iris pale golden (Pl. 4, Fig. 2). The call is a soft "braa" usually followed by three high notes: "braaa-eep-ee-eep." In Michoacán this subspecies has been found only in the coastal region and the lower foothills of the Sierra de Coalcomán, an area in which it replaces _Tomodactylus nitidus petersi_. This is the only _Tomodactylus_ known to inhabit coastal lowlands. ~Tomodactylus nitidus petersi~ Duellman _Tomodactylus petersi_ Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 560:5, October 22, 1954.--Coalcomán, Michoacán, México. _Tomodactylus nitidus petersi_, Dixon, Texas Jour. Sci., 9:390, December, 1957. Aguililla; Apatzingán (8); Cascada Tzararacua: Charapendo (5); Coalcomán (5); 18 km. E of Dos Aguas (6); El Sabino (5); La Playa (2); Jiquilpan; Uruapan (2); Volcán Jorullo; Zamora. In life, specimens from Apatzingán (UMMZ 114308-9) varied in dorsal color from grayish tan to pale brown; the dorsal markings were olive green. The thighs and groin were yellowish orange; the iris was pale golden, and the vocal sac was purplish gray (Pl. 5, Fig. 1). Measurements for 13 adult males from the Tepalcatepec Valley are: snout-vent length, 21.9-26.8 (24.3); tibia length, 8.4-9.9 (9.3); head width, 7.2-9.2 (7.8); head length, 7.6-8.7 (8.2). At Apatzingán and Charapendo in the Tepalcatepec Valley males were found calling from rocks and bushes in open arid tropical scrub forest. The call, a triple note "peep-ee-eep," is repeated once every 90 to 135 seconds. _Tomodactylus nitidus petersi_ probably ranges throughout the Tepalcatepec Valley and surrounding foothills. Dixon (1957:392) referred the specimens from Zamora, Jiquilpan, and Uruapan to this subspecies. Uruapan is near the lower limits of the pine forest on the slopes of the Cordillera Volcánica; Zamora and Jiquilpan are on a low part of the Mexican Plateau southeast of Lago de Chapala. ~Tomodactylus rufescens~ Duellman and Dixon _Tomodactylus rufescens_ Duellman and Dixon, Texas Jour. Sci., 11:78, March, 1959.--Dos Aguas, Michoacán, México. Dos Aguas (14); 18 km. E of Dos Aguas (6). Fourteen specimens from the pine-oak forests around Dos Aguas (UMMZ 118503-10, 121498-9) have reddish brown dorsal color and a narrow cream-colored middorsal line (Pl. 5, Fig. 2). Twelve of these specimens are adult males having snout-vent lengths of 20.7 to 24.6 (22.5) mm. One female has a snout-vent length of 24.8 mm., and one juvenile has a snout-vent length of 14.5 mm. Six specimens are from a region of mixture of pine-oak forest and arid tropical scrub forest at 18 kilometers east of Dos Aguas (UMMZ 121497, 121500). All are males having snout-vent lengths of 18.0 to 22.6 (20.7) mm. The dorsum is tan marked with black; the thighs are yellowish orange. The specimens from 18 kilometers east of Dos Aguas were found on July 22, 1960, by Floyd L. Downs and John Winklemann, who collected calling males of _Tomodactylus rufescens_ and _Tomodactylus nitidus petersi_ at the same locality. Downs (_personal communication_) stated the call was a single note. At Dos Aguas I heard _T. rufescens_ give two calls, one a single "peep," the other a triple note--"pee-ee-eep." In the higher parts of the Sierra de Coalcomán _Tomodactylus rufescens_ seems to fill the same niche as _T. angustidigitorum_ does in the Cordillera Volcánica. At lower elevations in their respective mountain ranges the species occur sympatrically with _T. nitidus petersi_. ~Diaglena reticulata~ Taylor _Diaglena reticulata_ Taylor, Univ. Kansas Sci. Bull., 28:60, May 15, 1942.--Cerro Arenal, Oaxaca, México. Nueva Italia (3); Ostula (7). Until recently frogs of the genus _Diaglena_ were known only from a few specimens from southern Sinaloa (_Diaglena spatulata_) and from the Pacific lowlands of the Isthmus of Tehuantepec (_Diaglena reticulata_). Peters (1955a) reported specimens from Ostula, Michoacán, and compared these specimens with one _D. reticulata_ from Tehuantepec, Oaxaca, and four _D. spatulata_ from Sinaloa. This comparison showed that the specimens from Michoacán, although showing some minor differences from _D. reticulata_, are closer to that species than to _D. spatulata_. Subsequent to Peters' work, series of both species of _Diaglena_, including additional specimens from Michoacán and from Colima, have been collected, and a more qualified comparison is now possible. In comparing specimens of _D. spatulata_ from southern Sinaloa (UMMZ 115322) with specimens of _D. reticulata_ from Tehuantepec, Oaxaca (UMMZ 115321), the differences noted by Taylor (1942c:60) were found to be constant. But specimens from Ostula, Michoacán (UMMZ 104418), and five individuals from Colima (TNHC 26379-83) were found to be intermediate in certain characters. The skin of the dorsum in _D. reticulata_ is granular; that in _D. spatulata_ is smooth. The skin in specimens from Ostula and Colima is slightly granular. The dorsal ground color of _D. reticulata_ is yellowish brown with dark reticulations; the dorsal ground color of _D. spatulata_ is olive-green. Specimens from Ostula and Colima most closely resemble those from Tehuantepec in coloration, but the reticulations are more coarse, and the ground color has an olive-green tint. _Diaglena reticulata_ also differs from _D. spatulata_ in having a larger over-all size, slightly broader head, a narrower interorbital distance, and a more pointed snout with a deeper labial shelf (Table 4). The specimens from Ostula and Colima are intermediate between _D. reticulata_ from Oaxaca and _D. spatulata_ from Sinaloa in body proportions. Of three specimens from the Tepalcatepec Valley (JRD 5991-3), only two are suitable for measuring. These specimens are smaller than adults from the coastal areas and have broader heads and snouts, but narrower interorbital distances, than specimens in the other samples (Table 4). The texture of the skin is like that of specimens from Ostula and Colima. The coloration resembles that of _D. reticulata_, but the reticulations are bold and form indistinct bands on the hind limbs. TABLE 4.--COMPARISON OF FOUR CHARACTERS IN FIVE SAMPLES OF DIAGLENA. (ALL DATA ARE FOR MALES; MEANS GIVEN IN PARENTHESES BELOW RANGES.) +-----------------+---------+----------+----------+---------+-----------+ | | | | Head | Inter- |Internarial| | | | | width | orbital | distance | | | Number |Snout-vent| |distance | | | Locality | of | length |----------+---------+-----------+ | |specimens| |Snout-vent| Head | Head | | | | | length | width | width | +-----------------+---------+----------+----------+---------+-----------+ | Oaxaca | 9 |71.1-87.5 |25.4-29.1 |63.0-71.4| 11.9-13.8 | | | | (80.7) | (27.9) | (67.1) | (12.9) | +-----------------+---------+----------+----------+---------+-----------+ | Coast of | 5 |72.0-79.2 |24.3-27.2 |67.0-73.8| 13.7-14.4 | | Michoacán | | (74.8) | (25.6) | (71.4) | (14.1) | +-----------------+---------+----------+----------+---------+-----------+ | Colima | 4 |71.7-79.6 |26.1-28.6 |70.5-75.3| 16.0-17.9 | | | | (74.8) | (27.4) | (72.0) | (16.6) | +-----------------+---------+----------+----------+---------+-----------+ | Tepalcatepec | 2 |63.0-65.4 |28.3-32.2 |57.3-62.4| 17.0-20.2 | | Valley | | (64.2) | (30.3) | (59.9) | (18.6) | +-----------------+---------+----------+----------+---------+-----------+ | Sinaloa | 11 |71.9-81.3 |24.0-27.3 |70.5-78.1| 15.0-17.3 | | | | (77.3) | (25.7) | (73.4) | (16.1) | +-----------------+---------+----------+----------+---------+-----------+ All specimens from Michoacán and Colima more closely approach _Diaglena reticulata_ than _D. spatulata_. The acquisition of additional specimens, especially from the area between Sinaloa and Colima and from Guerrero, is necessary to determine the relationships among the various populations known at present. Both species of _Diaglena_ inhabit tropical scrub forest; none has been found in the more humid and tropical semi-deciduous forests. Humid forest replaces the scrub forest in the lowlands of southern Nayarit and northern Jalisco; possibly this forest acts as a barrier to the distribution of _Diaglena_ and thus serves as a divider between the ranges of _D. spatulata_ to the north and _D. reticulata_ to the south. ~Pternohyla fodiens~ Boulenger _Pternohyla fodiens_ Boulenger, Ann. Mag. Nat. Hist., ser. 5, 10:326, 1882.--Presidio, Sinaloa, México. Nueva Italia (2). These specimens (JRD 5994-5) were found on the road near Nueva Italia during a heavy rain on the night of August 25, 1960, by James R. Dixon. Both are females having snout-vent lengths of 64.0 and 59.0 mm. They are typical of the species as it is known from Sinaloa, Nayarit, Jalisco, and Colima. These specimens constitute the southernmost record for the species, which ranges in semi-arid habitats from southern Arizona southward along the Pacific lowlands of México to Colima and inland on the Mexican Plateau in Jalisco. ~Phyllomedusa dacnicolor~ Cope _Phyllomedusa dacnicolor_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:181, September 30, 1864.--Colima, Colima, México. Funkhouser, Occ. Pap. Nat. Hist. Mus. Stanford Univ., 5:37, April 1, 1957. _Agalychnis alcorni_ Taylor, Copeia, no. 2:31, June 2, 1952.--Río Tepalcatepec, 17 miles south of Apatzingán, Michoacán, México. _Agalychnis dacnicolor_, Duellman, Herpetologica, 13:29, March 30, 1957. _Phyllomedusa alcorni_, Funkhouser, Occ. Pap. Nat. Hist. Mus. Stanford Univ., 5:30, April 1, 1957. Aguililla (13); Apatzingán (7); Charapendo; Coahuayana (3); Coalcomán (54); El Sabino; Huetamo Road (2); La Orilla; La Placita; Nueva Italia (4); 32 km. E of Neuva Italia (2); Río Cancita, 14 km. E of Apatzingán; Río Tepalcatepec, 27 km. S of Apatzingán; Salitre de Estopilas (2); Tzitzio (4). This large tree frog has been found only in the lowlands below elevation of about 1000 meters, usually in arid tropical scrub forest. Calling males were heard on rainy nights throughout the rainy season; in nearly every instance both males and females were found in low trees and bushes. On summer nights when there had been no rain, adults were found sitting on bushes in the scrub forest. At Coalcomán on July 1, 1955, a chorus was heard at midday. About forty _Phyllomedusa dacnicolor_ were found in one guayava bush at the edge of a recently dried pond. Individual males were calling; clasping males were silent. The call is a barking groan. Fifteen individual egg masses were hanging from branches and leaves in tear-drop fashion. Each egg mass contained 100 to 350 pale green eggs, located only in the exterior part of the clear gelatinous mass. Two composite egg masses appeared to have been made up by egg deposition on the part of three to five females (Pl. 2, Fig. 2). As shown by Duellman (1957a), the characters used by Taylor (1952) to diagnose _Phyllomedusa alcorni_ are sexually dimorphic. Funkhouser (1957) apparently was unaware of this sexual dimorphism, for she recognized _P. alcorni_ and _P. dacnicolor_ as distinct species. ~Phrynohyas inflata~ (Taylor) _Acrodytes inflata_ Taylor, Univ. Kansas Sci. Bull., 30:64, June 12, 1944.--La Venta, Guerrero, México. _Phrynohyas inflata_, Duellman, Misc. Publ. Mus. Zool. Univ. Michigan, 96:19, February 1, 1956. _Phrynohyas corasterias_ Shannon and Humphrey, Herpetologica, 13:15, March 30, 1957.--4.8 miles east of San Blas, Nayarit, México. Barranca de Bejuco. One specimen of this large species was collected in 1951; it was found on a low branch in tropical semi-deciduous forest at an elevation of 65 meters. In life there were olive-gray blotches on a pale gray dorsum; the iris was a dark golden color. This species, which is known from only a few specimens, seems to be restricted to the coastal lowlands and low foothills from Guerrero northward to Nayarit. Shannon and Humphrey (1957) described _Phrynohyas corasterias_ from Nayarit. Their description was based on a small female having a snout-vent length of 34.4 mm. The new species was diagnosed as differing from _P. inflata_ in having less webbing on the feet, a poorly developed supratympanic fold, a more pustulate dorsum, and marked differences in dorsal pattern, color, and nature of antebrachial banding. The significance of the webbing was questioned by Shannon and Humphrey. The nature of the supratympanic fold and dorsal pustules changes with age (Duellman, 1956a:31). _Phrynohyas inflata_ is known to attain a snout-vent length of 95 mm. Dermal structures that undergo ontogenetic change are of little importance in comparing a juvenile with a large adult. The only significant difference in color pattern between _P. inflata_ and _P. corasterias_ is the presence of wide transverse bands on the limbs of the latter. In this respect _P. corasterias_ approaches _P. latifasciata_, a species known only from two specimens from southern Sinaloa. The acquisition of additional specimens from Jalisco, Nayarit, and Sinaloa may show that _P. inflata_ and _P. latifasciata_ are conspecific, as suggested by Duellman (1956a:21). Nonetheless, the specimen on which the description of _P. corasterias_ was based is not sufficiently different from the known specimens of _P. inflata_ to warrant specific recognition. ~Hyla arenicolor~ _Hyla arenicolor_ Cope, Jour. Acad. Nat. Sci. Philadelphia, ser. 2, 6:84, July, 1866.--Northern Sonora, México. Type locality restricted to Santa Rita Mountains, Pima County, Arizona, by Smith and Taylor (1950a:354). Agua Cerca; Cascada Tzararacua (3); Chinapa; Cojumatlán; Dos Aguas; El Sabino (25); El Espinal; Lago de Camécuaro; Lombardia (2); Tupátaro; Zinapécuaro. Altitudinally this frog ranges from 500 to 2100 meters; although the environments in which it has been found vary from open arid tropical scrub forest to pine forest, it usually is found near rocky streams in these habitats. There is great disparity in size between specimens from the mountains and those from the Tepalcatepec Valley. Seven males from elevations in excess of 1400 meters have an average snout-vent length of 34.7 mm.; nine from elevations below 1000 meters have an average snout-vent length of 49.1 mm. In life a male collected at night at Lombardia (UMMZ 112846) had dark brown spots on a grayish brown dorsum; the groin, anterior and posterior surfaces of the thighs, and ventral surfaces of the hind limbs and palms were yellowish orange. The belly and tips of digits were white; the vocal sac was purplish brown, and the iris was dark grayish gold. In contrast, a specimen obtained in the daytime at Chinapa (UMMZ 119204) had indistinct gray spots on a pale ashy gray dorsum; the flash colors were yellow. After dark the spots were dark olive-brown on a grayish brown dorsum. Two males were found calling from a rocky stream near Lombardia on July 12, 1955. The call is a nasal "ah-ah-ah-ah." ~Hyla baudini~ Duméril and Bibron _Hyla baudinii_ Duméril and Bibron, Erpétologie générale, vol. 8:564, 1841.--México. Type locality restricted to Córdoba, Veracruz, México, by Smith and Taylor (1950a:346). Aguililla (5); Apatzingán (30); Arteaga; Buena Vista; Charapendo; Coahuayana; Cofradía (4); El Sabino (12); La Placita; La Playa; Maruata; Nueva Italia (3); 32 km. E of Nueva Italia (2); Ostula (4); Río Tepalcatepec, 25 km. S of Apatzingán (3); Salitre de Estopilas; San José de la Montaña (2); Tumbiscatio; Tzitzio. This tree frog is widespread in the coastal lowlands and in the Tepalcatepec Valley up to elevations of about 1200 meters. It is found in numbers in the early part of the rainy season, at which time males were heard calling from bushes and trees along ditches and temporary ponds. The call is a loud nasal "waank-waank-waank." One individual that was emitting a long and unusually high-pitched call was found to have one hind limb engulfed by a _Leptodeira maculata_. When active at night these frogs usually are pale tan to reddish brown above with dark brown markings. A specimen found sitting on a maguey plant in the daytime was pale ashy gray with a pale green upper lip. ~Hyla bistincta~ Cope _Hyla bistincta_ Cope, Proc. Amer. Philos. Soc., 17:87, 1877.--Veracruz, México. Type locality restricted to Acultzingo, Veracruz, México, by Smith and Taylor (1950a:346). Cerro San Andrés; Dos Aguas (2); Los Conejos (3); Uruapan (50). In the Parque Nacional at Uruapan this species was found in abundance during the day. The frogs hide in an entanglement of vines and vegetation overhanging several small spring-fed streams. Tadpoles were in the rocky streams, and metamorphosing young were on vegetation at the edges of the streams. In life the dorsum is greenish tan with brown mottling; in some individuals the entire dorsum is dark chocolate brown. The flanks are pale lemon yellow barred with lavender-brown. Notes on the color of a living frog from Dos Aguas (UMMZ 119193) are: Dorsal ground color a medium shade of brown with dark brown flecks; flanks black with silvery white and pale yellow spots; belly pale yellowish white; throat mottled with grayish brown; iris pale copper color. [Illustration: FIG. 8. Tadpole of _Hyla bistincta_ (UMMZ 115231) from Uruapan, Michoacán. × 2.] Description of Tadpole: Body somewhat depressed; maximum width of body slightly more than one-half of body length. Nostrils placed dorsolaterally and directed anteriorly, situated about midway between tip of snout and eye. Eyes of moderate size, dorsolateral in position and directed upwards. Tail about twice as long as body, thrice as long as deep, and tapering gradually to a rounded tip. Tail-musculature not extending to tip of tail fin. Spiracle sinistral, lateral, and situated at midbody. Vent dextral; the cloacal tube extending along ventral part of tail for a distance equal to about one-eighth of body length (Fig. 8). Average body length of six tadpoles with small hind limb buds, 19.5 mm.; tail length, 38.3 mm. Mouth ventral, its width equal to about two-thirds of greatest width of body. Lips bordered by two rows of small papillae; row of larger papillae between upper lip and outer upper tooth-row, similar row between lower lip and outer lower tooth-row; laterally these rows degenerating into numerous small papillae. Horny beaks well developed; upper beak moderately arched and deeply indented; lower beak slightly indented. Serrations of beaks blunt and peglike, moderately developed on both beaks, but slightly stronger on lower one. Tooth-rows 2/3; upper rows nearly equal in length and slightly longer than lower rows, which are subequal in length; inner upper tooth row interrupted medially by rounded notch; inner lower tooth-row turned downward laterally; teeth in all rows about equal in size, but decreasing in length laterally (Fig. 9). [Illustration: FIG. 9. Mouthparts of larval _Hyla bistincta_ (UMMZ 115231) from Uruapan, Michoacán. × 15.] Color in formalin: pale grayish brown dorsally and laterally; pale gray ventrally; tail-musculature brown; tail-fin translucent with scattered melanophores most numerous on upper fin. In most details these tadpoles resemble those of _Hyla robertsorum_ described by Rabb and Mosimann (1955). Four metamorphosing young have snout-vent lengths of 23.0-23.5 (23.2); a completely metamorphosed individual has a snout-vent length of 24.8 mm. In Michoacán this stream-breeding hylid occurs at elevations of 1,600 to 2,400 meters in the Sierra de Coalcomán and in the mountains rising from the Mexican Plateau. ~Hyla eximia~ Baird _Hyla eximia_ Baird, Proc. Acad. Nat. Sci. Philadelphia, 7:61, October 20, 1854.--Valley of México. Type locality restricted to Coyoacán, Distrito Federal, México, by Smith and Taylor (1950a:329). _Hyla microeximia_ Maslin, Herpetologica, 13:81, July 10, 1957.--3 miles northwest of Jocotepec, Jalisco, México. Ciudad Hidalgo (36); Cuitzeo; 29 km. NW of Jacona; Jiquilpan (2); Lago de Camécuaro (2); Lago de Pátzcuaro (129); Los Reyes; Morelia; Sahuayo (3); San Gregorio (63); Tangamandapio (4); Temazcal (26); Tupátaro; Tuxpan (15); Undameo (2); Uruapan (20); Zacapu; Zamora (27); Zinapécuaro (10). More than 80 per cent of the specimens from Michoacán have brown spots between the lateral and dorsolateral dark stripes, and more than 50 per cent have spots between the dorsolateral stripes, at least posteriorly. In comparison with specimens from the Valley of México, those from Michoacán have more distinct dorsolateral stripes that extend farther anteriorly, sometimes to the eyelid, and in this respect are more nearly like those from Jalisco and Nayarit (Taylor, 1939b:425). Some specimens from the western part of Michoacán possess certain characters used by Maslin (1957:81) to distinguish _Hyla microeximia_ from _H. eximia_; nevertheless, the variation is such that two species cannot be distinguished in Michoacán. Four series of freshly preserved specimens have been studied in detail; in the discussion below they are arranged from west to east; the measurement is for snout-vent length of ten males from each sample: _Zamora._--Twenty-two specimens (UMMZ 102083), 24.0-27.6 (26.1) mm. Dorsolateral dark stripe, or row of dashes, present in all specimens; dark spots in lateral and dorsal green fields; lateral dark stripe confluent with dorsolateral stripe posteriorly in 18 specimens; white line not extending to groin. _Temazcal._--Thirty-five specimens (UMMZ 119162), 26.5-31.1 (28.2) mm. Dorsolateral dark stripe of row of spots present only posteriorly in most; both dorsolateral stripes and dorsal spots lacking in four specimens; heavy spotting dorsally in three others; lateral and dorsolateral dark stripes confluent posteriorly in three; lateral white stripe extending to groin in 16 specimens. _Ciudad Hidalgo._--Thirty-six specimens (UMMZ 119163), 26.4-30.9 (28.2) mm. Dorsolateral dark stripe or row of spots present only posteriorly in most; no brown spots in the green fields of many specimens; large brown inguinal spot in most specimens; heavy spotting dorsally in four; lateral and dorsolateral dark stripes confluent posteriorly in five; lateral white line extending to groin in most specimens. _Tuxpan._--Fifteen specimens (UMMZ 115227), 28.7-33.0 (30.5) mm. Dorsolateral dark stripe or row of dashes in all specimens; dark spots in lateral green fields, at least posteriorly in most; dark spots posteriorly in the dorsal green field in five; lateral dark stripe separated from dorsolateral stripe in all specimens; lateral white line extends to the groin in all specimens. As can be seen from the above descriptions, the distinguishing characters of _Hyla microeximia_--confluence of lateral and dorsolateral dark stripes posteriorly, extent of lateral white stripe, and distribution of dark spots dorsally--are found in individuals from all of the populations sampled. In the samples from western Michoacán there is a higher incidence of _microeximia_-like frogs than in those from other parts of the state. _Hyla eximia_ is a wide-ranging species varying greatly geographically and individually. A thorough review of the species and related members of the _Hyla eximia_-group is necessary before certain populations can justifiably be segregated as subspecies or species. In Michoacán _Hyla eximia_ has been collected in mesquite-grassland, pine-oak forest, and cultivated areas on the Mexican Plateau from 1500 to 2300 meters; apparently it is absent from the Sierra de Coalcomán. This is the most abundant frog on the southern part of the Mexican Plateau; in the rainy season breeding choruses are found in temporary pools and in the marshes adjacent to the permanent lakes. ~Hyla lafrentzi~ Mertens and Wolterstorff _Hyla lafrentzi_ Mertens and Wolterstorff, Zool. Anz., 84:235, August 25, 1929.--Desierto de los Leones, Distrito Federal, México. Cerro San Andrés (26); Opopeo (9). In March, 1949, James A. Peters collected this species at elevations of 2400 to 2800 meters on the west slope of Cerro San Andrés. The frogs were found beneath logs and rocks in a damp canyon in coniferous forest. Among the juveniles in this series is a completely transformed individual (UMMZ 102093) having a snout-vent length of 14.5 mm. Five adults have snout-vent lengths of 36.2-39.5 (38.0) mm. _Hyla lafrentzi_ has noticeably longer hind limbs than _H. eximia_; in the former, when the hind limb is brought forward along the body, the tibiotarsal articulation extends to the snout. There are dark transverse bands on the hind limbs; the dorsolateral stripe is broken into an anterior and a posterior segment, and the latter is narrowly bordered by white in most specimens. _Hyla lafrentzi_ occurs at higher elevations than any other frog in Michoacán; the locality records from throughout the range indicate that it is restricted to pine and pine-fir forests. In these habitats it replaces _Hyla eximia_, which inhabits the lower pine-oak forests and mesquite-grassland on the Mexican Plateau. Ponds are absent at places where _Hyla lafrentzi_ has been collected; possibly the eggs are laid in streams. ~Hyla smaragdina~ Taylor _Hyla smaragdina_ Taylor, Copeia, No. 1:18, March 30, 1940.--6 kilometers east of Cojumatlán, Michoacán, México. _Hylella azteca_ Taylor, Proc. Biol. Soc. Washington, 56:49, June 16, 1943.--Tepoztlán, Morelos, México. Cojumatlán (30); Copuyo (7); 18 km. E of Dos Aguas (22); Ostula (8); Pómaro (3); Sahuayo; Salitre de Estopilas (7). Taylor (1940a:18) diagnosed this species as having few or no vomerine teeth, no vocal sac, a rather broad and flat head, two large tubercles below the anus, a granular venter, and a green dorsum in life. The specimens on which the description was based are either immature or non-breeding individuals; all were collected from bromeliads growing on cacti near Cojumatlán. Another small, flat-headed hylid from Tepoztlán, Morelos, was described and diagnosed by Taylor (1943b:49) as differing from _Hyla smaragdina_ in having a vocal sac and a broader head. This specimen was named _Hylella azteca_. Specimens from the coastal region of Michoacán and Colima were referred to _Hylella azteca_ by Peters (1954:7) and Duellman (1958c:8). Comparison of topotypic _Hyla smaragdina_ and the holotype of _Hylella azteca_ (UIMNH 25044) with the several series of specimens from Michoacán has resulted in the conclusion that all pertain to only one species. Although the type series of _Hyla smaragdina_ consists of immature specimens, the males in that series do possess vocal sacs. Since these were not breeding individuals, the sacs are not well developed. The characters of the anal tubercles and the relative width of the head are of no value in separating the two species. The apparently aestivating individuals comprising the type series of _Hyla smaragdina_, and the type of _Hylella azteca_, which also was found in a bromeliad, were green in life. Of the calling males found on the coast of Michoacán, most were yellowish tan when found; two were pale green, but soon changed to pale tan. Calling males from Copuyo and Dos Aguas were pale yellowish tan. Therefore the color of the dorsum is of little significance in distinguishing the two named populations. Males of _Hyla smaragdina_ have been found calling in the months of June and July from rocky streams; the call is a nasal "haah-haah-haah," repeated quickly and constantly for as long as 30 seconds. As pointed out by Duellman (1958c:9), this breeding behavior is unlike that suggested by Taylor (1943b:51). In Michoacán _Hyla smaragdina_ has been found in tropical semi-deciduous forest, oak forest, and mesquite-grassland at elevations from 150 to 1500 meters. ~Hyla smithi~ Boulenger _Hyla smithi_ Boulenger, Zool. Rec. Reptilia and Batrachia, 38:33, 1902.--Cuernavaca, Morelos, México. Aguililla (14); Apatzingán (104); Arteaga; Charapendo (5); Coalcomán (11); El Sabino (44); La Playa (6); Lombardia (2); Nueva Italia (8); Playa Azul; Salitre de Estopilas (2). This small hylid is abundant in the Tepalcatepec Valley to elevations of about 1000 meters; it was found infrequently on the coastal lowlands. Males call from bushes in and around flooded fields and ditches, from grasses and small herbs in the water and from vegetation overhanging small streams. The call consists of a series of short, high notes, somewhat reminiscent of a katydid's song. In the dry season occasional males were heard calling from irrigated fields near Apatzingán. In the daytime individuals were found in the axils of leaves of the elephant-ear plants (_Xanthosoma_). In living individuals the dorsal color usually is uniform pale yellow; often the lateral white stripe is barely visible. The vocal sac is bright yellow, and the iris is pale gold. In some individuals there are scattered dark brown spots or flecks on the back and upper surfaces of limbs. Twenty males from Apatzingán have the following measurements: snout-vent length, 22.8-26.0 (25.0) mm., tibia length, 10.7-13.6 (12.6) mm.; head width, 7.2-8.0 (7.6) mm., head length, 7.1-8.1 (7.7) mm. ~Hypopachus caprimimus~ Taylor _Hypopachus caprimimus_ Taylor, Univ. Kansas Sci. Bull., 26:526, November 27, 1940.--Agua del Obispo, Guerrero, México. Buena Vista; Copuyo (6); Charapendo (3); Cofradía; Jaramillo; Jungapeo; San Salvador; Tuxpan. Specimens of _Hypopachus_ from the Balsas drainage in Michoacán have characters consistent with topotypic _H. caprimimus_. Eleven specimens from the southern edge of the Mexican Plateau all have the flanks darker than the dorsum, a distinct and continuous dark stripe from the occiput to the groin, a large dark spot in the inguinal region, and a pair of dark transverse stripes on the thigh and shank (Pl. 6, Fig. 1). With the exception of three specimens from Charapendo, all have a predominantly brown venter with round, cream-colored spots. Peters (1954:8) referred specimens from Buena Vista and San Salvador to _Hypopachus oxyrrhinus_. He stated that the specimen (BMNH 1914.1.28.150) from San Salvador had flanks much darker than the dorsum and a well-defined continuous stripe from the occiput to the groin; this specimen has the characters of _H. caprimimus_. The specimen (BMNH 1914.1.28.151) from Buena Vista resembles _H. oxyrrhinus_ in some characters, but it is not like _H. oxyrrhinus ovis_ on the Mexican Plateau in Michoacán. The specimen has paired transverse stripes on the hind limbs as does _H. caprimimus_, and is here referred to that species. In Michoacán this species has been collected in arid tropical scrub forest at elevations of 200 to 1800 meters in the northern foothills of the Sierra de Coalcomán, the Tepalcatepec and Tuxpan valleys, and on the lower slopes of the Cordillera Volcánica. Calling males have been found along streams. One specimen from Charapendo was regurgitated by a _Leptodeira maculata_. ~Hypopachus oxyrrhinus ovis~ Taylor _Hypopachus ovis_ Taylor, Univ. Kansas Sci. Bull., 26:520, November 27, 1940.--Tepic, Nayarit, México. _Hypopachus oxyrrhinus ovis_, Shannon and Humphrey, Herpetologica, 14:89, July 23, 1958. Emiliano Zapata; 30 km. NW of Jacona (2); 10 km. NE of Pátzcuaro (2); Tangamandapio (16); 24 km. W of Zamora (16). Thirty-seven specimens from the Mexican Plateau in northwestern Michoacán agree well with the diagnosis of _Hypopachus oxyrrhinus ovis_ by Shannon and Humphrey (1958). With the exception of one specimen from Tangamandapio, all have dark bellies extensively mottled or spotted with cream-color. Most of the specimens have some form of an irregular, usually broken, dark line from the occiput to the groin. In eight specimens there is no line or linear arrangement of spots; instead the dorsum is spotted or flecked with dark brown. The ground color of the dorsum and flanks varies from dull reddish brown to grayish brown; cream-colored spots are evident on the flanks and posterior surfaces of the thighs in all specimens (Pl. 6, Fig. 2). In comparison with 14 specimens from Quesería, Colima (UMMZ 80001-2), individuals from the Mexican Plateau have a darker venter with bolder markings, and a more mottled dorsum. In Michoacán this species has been taken between 1500 and 2200 meters on the Mexican Plateau, where it inhabits mesquite-grassland and cultivated areas. ~Rana dunni~ Zweifel _Rana dunni_ Zweifel, Copeia, no. 2:78, July 15, 1957.--Lago de Pátzcuaro, Michoacán, México. Lago de Pátzcuaro (23); Río de Morelia, near Undameo (8). Aside from the type series of this species, there are in the Museum of Zoology at the University of Michigan six specimens taken from "tanks" at the limnological station at Pátzcuaro by Paul S. Martin in 1948, and eight specimens found in shaded ditches along the Río de Morelia by Robert R. Miller on April 4, 1957. The Río de Morelia flows into Lago de Cuitzeo; this drainage is separated from Lago de Pátzcuaro by a chain of hills about 2400 meters in elevation. Dr. Richard G. Zweifel has examined these specimens and has informed me that, although they differ slightly from typical _Rana dunni_, they are much closer to that species than to _Rana montezumae_. ~Rana megapoda~ Taylor _Rana megapoda_ Taylor, Univ. Kansas Sci. Bull., 28:310, November 12, 1942.--Chapala, Jalisco, México. La Palma (8). These specimens (USNM 113998-114005) are from the marshes along the southeastern shore of Lago de Chapala. Five females have snout-vent lengths of 124.0-138.1 (131.5), and one male has a snout-vent length of 110.2 mm. Two juveniles have snout-vent lengths of 49.7 and 56.3 mm. The coloration of the juveniles is more bold than that of the adults. The body proportions of these specimens agree with those presented by Zweifel (1957:80). ~Rana montezumae~ Baird _Rana montezumae_ Baird, Proc. Acad. Nat. Sci. Philadelphia, 7:61, October 20, 1854.--Mexico City, Distrito Federal, México. La Palma; 8 km. NW of Maravatio (10); Sahuayo; Tupátaro (7). This species probably is more abundant and widespread than is indicated by the few specimens listed above. It has been found only in the vicinity of permanent water on the Mexican Plateau and the mountains rising from the plateau at elevations of 1500 to 2000 meters. Its apparent absence from Lago de Pátzcuaro cannot be explained, unless _Rana dunni_ replaces it there. ~Rana pipiens~ Schreber _Rana pipiens_ Schreber, Der Naturforscher, Halle, 18:185, 1782.--Raccoon, Gloucester County, New Jersey. Aguililla (2); Apatzingán (13); Arteaga; Axolotl (16); Camachines (2); Capirio; Cascada Tzararacua (3); Cerro San Andrés (6); Charapendo (4); Ciudad Hidalgo; Coalcomán (17); Cuitzeo (3); El Sabino (10); Jacona (3); 29 km. NW of Jacona (8); Jiquilpan; La Orilla (3); La Palma (5); La Playa (4); Lago de Chapala (3); Lago de Pátzcuaro (6); Lombardia; Los Conejos (67); Los Reyes (7); Macho de Agua; Maravatio; Morelia (5); Opopeo (3); Pátzcuaro (9); 26 km. S of Pátzcuaro (52); Puerto Hondo (3); Río Duero, 14 km. E of Zamora (13); Río Tepalcatepec, 27 km. S of Apatzingán (2); San Gregorio (38); San José de la Cumbre (5); Tangamandapio; Zacapu; 18 km. W of Zamora (35). Except on the Pacific lowlands, this species is abundant throughout the state. It has been collected from sea level to 2800 meters, the greatest altitudinal range of any amphibian in Michoacán. It has been found frequently in the Tepalcatepec Valley; it is not a distinctly highland species in southern Michoacán, as stated by Peters (1954:9). One specimen from Aguililla (UMMZ 119257) is an albino. In this specimen there is a faint pattern on the hind limbs; otherwise the entire body is creamy white; the eyes are pink. ~Rana pustulosa~ Boulenger _Rana pustulosa_ Boulenger, Ann. Mag. Nat. Hist., ser. 5, 11:343, 1883.--Ventanas, Durango, México. Arteaga (4); 21 km. S of Arteaga; Cascada Tzararacua (3); Coalcomán (3); 12 km. ENE of Dos Aguas (3); El Sabino (53); Los Reyes (3); Tzitzio (4); Uruapan. Although _Rana pustulosa_ seems to be absent from the Mexican Plateau in Michoacán, it has been collected at elevations of 850 to 2150 meters on the slopes of the Cordillera Volcánico and in the Sierra de Coalcomán. Usually the frogs are found along rocky streams, but at Coalcomán they were found in a hyacinth-choked old river channel, and at El Sabino, in irrigation ditches. In most specimens the dorsum is dark olive-brown; in some it is pale olive-tan with dense dark brown mottling on the back and dark transverse bands on the hind limbs. Thirteen tadpoles (UMMZ 94271) taken from a seepage pool by a stream near Uruapan closely resemble the description of tadpoles of this species given by Taylor (1942b). REPTILIA Testudines ~Chelonia mydas~ (Linnaeus) _Testudo mydas_ Linnaeus, Systema naturae, ed. 10:197, 1758.--Type locality restricted to Ascension Island by Mertens and Müller (1928:23). _Chelonia mydas_, Brongniart, Bull. Sci. Soc. Philom., 2:89, 1800. Beach between Río Motín and Río Colotlán (2); Maruata; Playa Azul (4). Green sea turtles are abundant along the coast of Michoacán. Laying females and fresh nests were found on August 6-12, 1950, July 14-16, 1951, and July 8-10, 1955. The general account of sea turtles on the coast of Michoacán that was given by Peters (1957) is supplemented here by my field notes on the actions of one female observed on the night of July 14, 1951, near Maruata by Donald D. Brand and I. Because of a full moon, visibility was excellent. In the course of the day several _Chelonia_ were seen in the surf; shortly after dark the first turtle was observed on the beach. Several were observed to come out on the beach and crawl nearly to the strand line, only to return to the sea. At 10:20 p. m. one turtle was seen about 15 meters from the water. We watched this turtle from some distance and observed that by 10:26 p. m. she had moved about ten meters to a bank of sand about two meters high. Ten minutes later she had climbed the bank and disappeared over the top into the brush. We moved closer and remained hidden below the bank. Although we could not see the turtle, we could hear her movements. Between 10:37 and 10:57 p. m. the turtle dug, often flipping the dry sand for a distance of about two meters. When this energetic digging ceased, we moved up the bank to see that she was facing inland and sitting in a depression about one and one-half meters in diameter and 30 centimeters in depth. She had cleaned out this depression in the past 20 minutes. Between 11:00 and 11:36 p. m. she dug the nest hole by first scooping sand with one hind flipper and then with the other; when sand was thrown by one flipper, there was a similar, but weaker, motion by the other flipper. At 11:36 p. m. she stopped digging. By crawling up behind the turtle we were able to examine the nest cavity, which measured 21 centimeters across the top and 38 centimeters deep. The diameter of the bottom of the hole was estimated to be about 50 centimeters. At 11:40 p. m. she released the first egg; a minute later she dropped the second. At 11:42 p. m. the third and fourth eggs were released; these were coherent, as were the fifth and sixth eggs released at 11:43 p. m. After this, as many as three eggs were dropped at a time. After laying about 60 eggs, she paused for a minute and then continued laying. By 11:55 p. m. she had laid 98 eggs; after this, the process of deposition slowed considerably. She dropped a fragment of an egg followed by normal eggs. At midnight she deposited a miniature egg about 20 mm. in diameter. This terminated the deposition. Immediately she began to cover the nest. Within ten minutes after the last egg was deposited the nest had been covered. The turtle first had been seen at 10:20 p. m.; judging from its speed and its distance from the water, the turtle probably had been on land for about ten minutes. About 25 minutes were used in crawling from the water to the nesting site. One hour and 33 minutes were spent at the nesting site; of this time twenty minutes were taken for egg deposition. The turtle was not followed back to the water, but if the return trip took approximately the same amount of time as required to travel from the ocean to the nesting site, the total elapsed time from departure to return to the water was about two and one-half hours. We collected the eggs as they were deposited. There were 106 eggs, each having a diameter of about 40 mm., plus one small egg and a fragment of another. The turtle had a carapace about one meter in length. From our limited observations of sea turtles and their tracks on the beaches, and from the accounts of these animals by the residents of the coastal region, great numbers of sea turtles use these relatively uninhabited beaches for nesting grounds. However, the turtles do not go unmolested. The natives capture turtles and collect their eggs. Opened and emptied nests also showed signs of predatory activity on the part of other mammals. In the vicinity of Playa Azul several turtles were killed by dogs. ~Kinosternon hirtipes hirtipes~ Wagler _Cinosternon hirtipes_ Wagler, Naturl. Syst. Amph., p. 37, 1830.--México. Type locality restricted to Mazatlán, Sinaloa, México, by Smith and Taylor (1950b:25). _Kinosternon hirtipes hirtipes_, Schmidt, Check list N Amer. Amph. Rept., ed. 6, p. 89, 1953. Eight km. W of Ciudad Hidalgo; Jiquilpan; La Palma; Lago de Camécuaro (4); Lago de Cuitzeo (3); Lago de Pátzcuaro (8); 14 km. E of Zamora (4). One specimen from eight kilometers west of Ciudad Hidalgo (UIMNH 24707) is from the Río Tuxpan, a tributary of the Río Balsas; this is the only record for the species from the Balsas drainage. All others are from the lakes or rivers flowing into the lakes on the southern part of the Mexican Plateau. This species exists in Lago de Pátzcuaro to the apparent exclusion of the abundant and widespread _Kinosternon integrum_. ~Kinosternon integrum~ LeConte _Kinosternon integrum_ LeConte, Proc. Acad. Nat. Sci. Philadelphia, 7:183, 1854.--México. Type locality restricted to Acapulco, Guerrero, México, by Smith and Taylor (1950b:25). Agua Cerca (3); Aguililla; Arteaga (8); Apatzingán (7); Barranca de Herradero; Buenavista (20); Capirio (2); Charapendo (3); Chupio; Coahuayana (2); Coalcomán (169); Copuyo (4); El Sabino (8); Jacona; Jiquilpan (12); La Orilla (2); La Playa (2); Lago de Cuitzeo (27); Las Higuertas; Lombardia (3); Los Reyes (5); Morelia; Ojos de Agua de San Telmo; San Pedro Naranjestila; Tacícuaro. Excepting Lago de Pátzcuaro, _Kinosternon integrum_ occupies all permanent and temporary ponds, lakes, and streams below 2200 meters throughout the state. At Coalcomán the species was in roadside ditches, small puddles, flooded fields, a hyacinth-choked ox-bow of the Río Coalcomán, as well as in the Río Coalcomán and its tributaries. Specimens from Arteaga and Barranca de Herradero were found in clear rocky streams; the one from Las Higuertas was found in a small muddy pond in pine-oak forest. On August 26, 1960, James R. Dixon found a copulating pair in a pool at Capirio. The large series from Coalcomán contains juveniles and adults; these turtles formed the basis for the study of relative growth of plastral scutes in this species by Mosimann (1956). ~Geoemyda rubida perixantha~ Mosimann and Rabb _Geoemyda rubida perixantha_ Mosimann and Rabb, Occ. Pap. Mus. Zool. Univ. Michigan, 548:1, November 9, 1953.--Eight kilometers south of Tecomán, Colima, México. Apatzingán (2); Coahuayana; La Placita; Punta San Juan de Lima. These specimens have been discussed in detail by Mosimann and Rabb (1953). All are from the arid tropical scrub forest; those from the coastal regions were collected at elevations of less than 40 meters, and those from the Tepalcatepec Valley were collected at an elevation of 335 meters. Crocodilia ~Crocodylus acutus acutus~ Cuvier _Crocodylus acutus_ Cuvier, Ann. Mus. Hist. Nat. Paris, 10:55, 1807.--Santo Domingo. _Crocodylus acutus acutus_, Müller and Hellmich, Ibero-Amerik. Stud., 13:128, 1940. Boca de Apiza (2); Playa Azul (2). The crocodile or "caiman" is abundant in the brackish lagoons along the cost of Michoacán; three large adults and several juveniles were observed at Estero Pichi at Playa Azul; others were seen at Mexiquillo and Maruata. Residents of the Balsas-Tepalcatepec Basin frequently have reported "caimanes" in the Río Balsas and Río Tepalcatepec, but the existence of the crocodile in these rivers has not been verified by specimens. Sauria ~Phyllodactylus duellmani~ Dixon _Phyllodactylus duellmani_ Dixon, Southwest Nat., 5:37, April 15, 1960.--Rancho El Espinal, Michoacán, México. Fourteen km. SSW of Apatzingán; Capirio; Cafradía (3); El Espinal (3). This species is known only from the Tepalcatepec Valley, where it has been found in open arid situations from 180 to 500 meters. Specimens were found in the daytime in stumps, dead cacti, and the hollow branches of the legume, _Apoplanesia paniculata_. In life adults were pale gray or grayish tan above and creamy white below. A juvenile having a snout-vent length of 18 mm. had a pale orange tail with gray cross-bands. In the adults the tail was colored like the body. The specimen from 14 kilometers south-southwest of Apatzingán (KU 29764) and those from Cofradía (BMNH 1914.1.28.28-30) were not listed by Dixon (1960). ~Phyllodactylus homolepidurus~ Smith _Phyllodactylus homolepidurus_ Smith, Univ. Kansas Sci. Bull., 22:121, November 15, 1935.--Five miles southwest of Hermosillo, Sonora, México. El Ticuiz (2); La Placita; Ostula (2); Pómaro; San Pedro Naranjestila. These specimens have been referred to _Phyllodactylus homolepidurus_ by James R. Dixon (_in litt._), who is currently studying the American members of the genus. Geckos of this species have been found in tropical semi-deciduous forest in the coastal lowlands to elevations of 500 meters. Most specimens were found beneath the bark of standing dead trees or stumps. Two individuals from El Ticuiz (UMMZ 115102) in life were dark gray above with brownish tubercles; the belly was a dusty cream-color. Apparently this species does not enter the Tepalcatepec Valley, where _Phyllodactylus lanei_ is abundant. ~Phyllodactylus lanei~ Smith _Phyllodactylus lanei_ Smith, Univ. Kansas Sci. Bull., 22:125, November 15, 1935.--Tierra Colorado, Guerrero, México. Apatzingán (13); 21 km. S of Arteaga: El Sabino (53); La Playa; Ostula (2); Río Marquez, 10 km. S of Lombardia (8); 16 km. N of Tafetán. This widespread species has been taken at elevations of less than 1100 meters in the Balsas-Tepalcatepec Basin, where it occurs in riparian situations in the foothills. Specimens have been collected in tropical semi-deciduous forest at Ostula and in oak forest south of Arteaga; both of these localities are on the Pacific slopes of the Sierra de Coalcomán, a region inhabited by _Phyllodactylus homolepidurus_. Both species have been collected at Ostula. A juvenile from 21 kilometers south of Arteaga (UMMZ 118933) had alternating black and white bands on the tail. In life most of the lizards are dull ashy gray or grayish tan above and white below. According to Dixon (_in litt._), one specimen from Apatzingán (UMMZ 115102) resembles _Phyllodactylus magnus_ in scutellation, but it lacks the distinctive yellow venter of that species. Apparently _Phyllodactylus lanei_ is restricted to rather mesic environments in the Balsas-Tepalcatepec Valley and surrounding foothills; in the more open arid environments on the floor of the valley it seems to be replaced by _Phyllodactylus duellmani_. ~Phyllodactylus paucituberculatus~ Dixon _Phyllodactylus paucituberculatus_ Dixon, Southwest. Nat., 5:40, April 15, 1960.--Río Cupatitzio (= Río Marquez), 6.5 miles south of Lombardia, Michoacán, México. Río Marquez, 10 km. S of Lombardia (6). Two of these specimens (UMMZ 112692-3) were discussed in detail by Dixon (1960:40) in his description of the species. On August 25, 1960, Dixon collected four additional specimens at the type locality, a conglomerate cliff along the Río Marquez. These will be reported by him in his forthcoming study of the genus. ~Anolis dunni~ Smith _Anolis dunni_ Smith, Copeia, no. 1:9, May 10, 1936.--Agua del Obispo, Guerrero, México. Arteaga (3); 19 km. S of Arteaga. Three females from Arteaga (UMMZ 119075) have snout-vent lengths of 41, 41, and 44 mm. In life the pale grayish brown dorsum was marked with dark brown; the belly was white, and the throat was pale pink. All have a dark interorbital bar and dark vertical bars on the upper labials. In two specimens there are only scattered dark flecks on the dorsum; in the third there is a dark postorbital stripe, a dark lateral stripe, and four narrow transverse bands on the body. A male from 19 kilometers south of Arteaga (UMMZ 119076) having a snout-vent length of 49 mm. had in life a tan dorsum, a broad white stripe from the ear to the groin, scattered small white spots on the dorsum, and indistinct pale cream-colored spots on the posterior surfaces of the thighs. This male has the dark labial bars, but lacks the dark interorbital bar, found in the females. The large rose-pink throat fan extends to about the middle of the belly. In all of the specimens the middorsal scales are keeled and much smaller than the smooth pavementlike or slightly imbricate ventrals. All have two gulars in contact with the mental, five scales between the nasals, five scales (not including the first labials) in contact with the rostral, and four rows of loreals. In these characters these specimens agree well with _Anolis dunni_ from Guerrero, as diagnosed by Davis (1954b). Previously _Anolis dunni_ has been reported only from the vicinity of Agua del Obispo, Guerrero, a locality situated at an elevation of about 900 meters in pine-oak forest in the Sierra del Sur. All known close relatives of _Anolis dunni_ occur only in Guerrero: _A. taylori_ Smith and Spieler from Acapulco, _A. gadowi_ Boulenger from Tierra Colorado, _A. liogaster_ Boulenger, and _A. omiltemanus_ Davis from Omiltemi. The present specimens from elevations of about 900 meters in riparian stream vegetation and oak forest represent the northern known limits of this group of _Anolis_. ~Anolis nebulosus~ (Wiegmann) _Dactyloa nebulosa_ Wiegmann, Herpetologia Mexicana, p. 47, 1834.--México. Type locality restricted to Mazatlán, Sinaloa, México, by Smith and Taylor (1950b:66). _Anolis nebulosas_, Bocourt, Mission Scientifique au Mexique et dan l'Amerique Centrale. Reptiles, livr. 2:77, 1873. Acahuato (3); Agua Cerca; Apatzingán (4); Araparicuaro (3); 29 km. S of Ario de Rosales (3); 20 km. S of Arteaga (2); Barranca de Bejuco; Cascada Tzararacua (5); Cerro Tancítaro (13); Cherán; Chupio (5); Coalcomán (10); Cofradía; Dos Aguas (10); 18 km. E of Dos Aguas (3); El Diezmo; El Sabino (43); El Ticuiz; Jiquilpan (2); La Orilla; La Placita; La Playa (3); Los Conejos (2); Los Pozos; Nogueleras (2); Ostula; 8 km. W of Pátzcuaro (2); 8 km. NE of Pátzcuaro; Playa Azul (3); Río Cachán; Río Marquez, 10 km. S of Lombardia; Río Tepalcatepec, 27 km. S of Apatzingán; San Juan de Lima (6); San Pedro Naranjestila; Temazcal; Tuxpan (2); Tzitzio; Uruapan (74); 11 km. N of Uruapan (2); Volcán Jorullo; 16 km. E of Zacapu (2); 18 km. W of Zamora; Ziracuaretiro. Even with the abundance of material the assignment of a specific name to these anoles is only tentative, for definite determination between _Anolis nebulosus_ Wiegmann and _A. nebuloides_ Bocourt is uncertain. Bocourt (1873:75) distinguished _A. nebuloides_ from _A. nebulosus_ by the following characters: (1) head scales keeled, not smooth; (2) snout narrower; (3) ear opening larger; (4) supraorbital semicircles separated by a row of small scales and not in contact; (5) dorsal scales larger and subequal in size to the belly scales. Boulenger (1885:77) used the same characters; Smith and Taylor (1950b:58) in their key to the Mexican species of _Anolis_ stated that the dorsal scales are slightly smaller than the ventrals in _A. nebulosus_ and markedly smaller in _A. nebuloides_. Smith (_in litt._) stated that the characters of the relative sizes of the dorsal and ventral scales were incorrect in that key. The application of the above criteria to specimens from Michoacán has not resulted in the recognition of two species. The majority of the specimens have the supraorbital semicircles separated by at least one small scale; the head scales, with the exception of those on the snout in a few individuals, are smooth; the dorsal scales are only slightly smaller than the ventrals. In other characters of scutellation the specimens are highly variable. The males in life have an orange throat fan. Anoles of this kind have been found in Michoacán, Colima, Jalisco, Nayarit, and southern Sinaloa. Near Oaxaca, Oaxaca, specimens were collected that superficially resemble those from Michoacán and farther north. These have low keels on the snout scales, dorsals somewhat larger than the ventrals, and a pink throat fan. In ten males from Oaxaca the size of the dorsal scales relative to that of the ventrals is 1.00:0.83; the same ratio for 25 males from Michoacán is 1.00:1.08. In both samples there are specimens in which the dorsal and ventral scales are about equal in size. Investigations by Richard E. Etheridge on the osteology of _Anolis_, including those species here being considered, have revealed relatively constant differences in the parasternalia and in the caudal vertebrae. The application of Etheridge's findings to anoline systematics must await the completion of his study. The carination of the scales on the snout _versus_ smooth scales there seems to be the only significant character given by Bocourt that distinguishes _A. Nebuloides_ from _A. nebulosus_. The difference in the color of the throat fan, which is apparent only in living individuals, is more striking. Obviously more than one species is represented, as is borne out by the differences in the color of the throat fan and in the osteology, but there is uncertainty about the correct name for each species. On the strength of Bocourt's diagnosis of keeled snout scales in _A. nebuloides_, I am applying that name to the population in Oaxaca and _A. nebulosus_ to the specimens from Michoacán. As arranged here, the two species can be distinguished, as follows: _A. nebulosus._--Dorsal scales only slightly smaller than the ventral scales; snout scales usually smooth; throat-fan bright orange in adult males. _A. nebuloides._--Dorsal scales somewhat larger than the ventral scales; snout scales having a low keel; throat-fan pink in adult males. With respect to geographic distribution, _A. nebulosus_ has been collected from southern Sinaloa southward to Michoacán. The lizards here referred to _A. nebuloides_ have been taken only in pine-oak forest on the mountain slopes near Oaxaca City. Zweifel and Norris (1955:233) reported anoles with pink throat-fans from southern Sonora; possibly those specimens are _A. nebuloides_; I have not examined them. I have seen several preserved specimens from the vicinity of Tehuantepec, Oaxaca. Although they probably belong to this group, those specimens differ from both _A. nebulosus_ and _A. nebuloides_ in their larger size, relatively larger head, and much larger throat fan. Aside from the minor variation in scutellation, specimens of _Anolis nebulosus_ from Michoacán vary greatly in coloration. Usually the females have some form of a broad middorsal pale-colored band. In life this is dull yellow, tan, or orange. Two females from Dos Aguas are strikingly different; one (UMMZ 119521) has a broad middorsal orange stripe that is scalloped laterally and bordered by gray. The other (UMMZ 119081) has a narrow middorsal cream-colored line. Males usually are unicolor brown or olive-tan; sometimes the middorsal region is darker. Some individuals have dark cross-bands or chevrons on the dorsum. One male from Dos Aguas (UMMZ 119080) has a cream-colored lateral stripe. In Michoacán _Anolis nebulosus_ occurs from sea level to elevations slightly in excess of 2100 meters, usually in areas of dense cover, whether this be herbaceous, viney, or woody, ordinarily on the ground as well as in bushes and trees. One was in a bromeliad growing about ten meters above the ground. In the arid Tepalcatepec Valley anoles of this species are most frequently found in the tangled growth along streams. Above Uruapan they were found in pine-oak forest, and on the Mexican Plateau between Zamora and Zacapu they were found in a bunch grass-scrub oak association. ~Anolis schmidti~ Smith _Anolis schmidti_ Smith, Publ. Field Mus. Nat. Hist., zool. ser., 24:21, January 30, 1939.--Manzanillo, Colima, México. La Placita; San Juan de Lima. Peters (1954:11) reported on the specimen from La Placita; another was secured at San Juan de Lima in 1956. The latter (UMMZ 115078) is a male having a snout-vent length of 43.0 mm. and a tail length of 70.5 mm. The dorsal ground color is pale tan; there are five pairs of irregular dark brown dorsolateral blotches. In life the throat fan was pale orange. These specimens agree with those from Colima described by Duellman (1958c:10). The distribution of _Anolis schmidti_ seems to be restricted to the coastal lowlands from Michoacán to Nayarit. ~Basiliscus vittatus~ Wiegmann _Basiliscus vittatus_ Wiegmann, Isis von Oken, 21:373, 1828.--México. Type locality restricted to Veracruz, Veracruz, México, by Smith and Taylor (1950b:72). Apatzingán (9); Capirio; Coahuayana (5); El Cerrito; El Sabino (2); El Ticuiz; La Placita (3); Maruata (2); Motín del Oro; Ostula; Playa Azul (3). This species has been found only on the coast and in the low Tepalcatepec Valley. In the latter area it is restricted to riparian situations along the larger streams. The lizard is abundant in the mangrove swamps bordering the brackish lagoons on the coast. In July, 1955, scores of individuals were seen around Estero Pichi at Playa Azul. Adults, especially the large males, are exceedingly wary and difficult to collect. At all localities where they were found, the lizards were most often seen in dense bushes, where they are well camouflaged. Individuals of all sizes were observed to run across the surface of the ponds. ~Iguana iguana rhinolopha~ Wiegmann _Iguana rhinolopha_ Wiegmann, Herpetologia Mexicana, p. 44, 1834.--México. Type locality restricted to Córdoba, Veracruz, México, by Smith and Taylor (1950b:72). _Iguana iguana rhinolopha_, Van Denburgh, Proc. Acad. Nat. Sci. Philadelphia, 1897:461, January 18, 1898. Apatzingán (8); Capirio (3); El Cerrito; El Ticuiz (2); La Placita; La Playa (2); Maruata; Playa Azul; Río Cachán. Like the preceding species, this lizard is always found near water. It does not ascend the foothills of the Sierra de Coalcomán, but in the Balsas Basin it reaches elevations of 800 meters at La Playa. Large adults are often seen in the large trees making up the gallery forests along rivers. From high perches the lizards drop into the water with a terrific splash. Bright green juveniles were abundant in bushes along the Río Tepalcatepec in July, 1955. ~Ctenosaura pectinata~ (Wiegmann) _Cyclura pectinata_ Wiegmann, Herpetologia Mexicana, p. 42, 1834.--México (by inference). Type locality restricted to Colima, Colima, México, by Bailey (1928:25). _Ctenosaura pectinata_, Gray, Catalogue of the lizards... British Museum, p. 191, 1845. Apatzingán (27); between Ario de Rosales and La Playa; Barranca de Bejuco; Capirio (2); Coalcomán (4); El Espinal; El Sabino (2); El Ticuiz; Jazmin (2); La Huacana; La Placita (8); La Playa (3); Limoncito; Lombardia; Motín del Oro; Playa Azul; Río Cancita, 12 km. E of Apatzingán (2); Río Marquez, 10 km. S of Lombardia (2);? Uruapan; Volcán Jorullo. _Ctenosaura pectinata_ is a common lowland species that ascends the slopes of the Sierra de Coalcomán and the Cordillera Volcánica to elevations of about 1050 meters (approximating the lower limits of the oak forest). The record from Uruapan (USNM 10234, collected by Dugès) is doubtful. These large lizards are most easily observed on rock fences along roads. Near Apatzingán innumerable individuals can be seen in mid-morning. Later in the day, as the sun rises higher in the sky, the lizards retreat to the shade of the crevices in the fences. The abundance of these lizards in the Tepalcatepec Valley, together with evidence gathered from the natives of the valley, indicates that these lizards are seldom used for human consumption there. On the other hand, several people in Coalcomán consider the "iguana negra" (local name for _Ctenosaura_) to be a delicacy and serve it at every opportunity. In early July, 1951, brilliant green young of the year were collected at La Playa and at Coalcomán. ~Enyaliosaurus clarki~ (Bailey) _Ctenosaura clarki_ Bailey, Proc. U. S. Natl. Mus., 73:44, September 26, 1928.--Ovopeo (= Oropeo), Michoacán, México. _Enyaliosaurus clarki_, Duellman and Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 598:1, February 16, 1959. Twelve km. SSW of Apatzingán; Capirio (7); Cofradía (3); El Espinal (2); 32 km. E of Huetamo; Jazmin (5); Oropeo (10); Rancho Nuevo; Río Cancita, 12 km. E of Apatzingán (8); Tepalcatepec (3); Zicuiran (6). This species is known only from the low areas of the Balsas-Tepalcatepec Basin between elevations of 200 and 510 meters. It is commonly found in the open arid tropical scrub forest dominated by _Prosopsis_ sp., _Apoplanesia paniculata_, and _Cercidium plurifoliolatum_. Continued collecting in the Tepalcatepec Valley has borne out the suggestions of Duellman and Duellman (1959) concerning the distribution and abundance of this lizard. Also, continued collecting in Colima and on the Pacific coast has failed to reveal the presence of _Enyaliosaurus_ there. ~Phrynosoma asio~ Cope _Phrynosoma asio_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:178, September 30, 1864.--Colima, Colima, México. Apatzingán (4); San Salvador. In Michoacán this species has been obtained only in the Tepalcatepec Valley and on the northern slopes of the Sierra de Coalcomán between 300 and 700 meters. Apparently the lizard is absent from the coastal lowlands of Michoacán and Guerrero. The distribution of this species, therefore, is discontinuous. One population inhabits the lowlands of Colima and the Balsas-Tepalcatepec Basin inland to northern Guerrero and Morelos; a southern population inhabits the Plains of Tehuantepec in Oaxaca. A juvenile from Apatzingán (USNM 47739) has a snout-vent length of 40.0 mm. and a tail length of 19.5 mm. ~Sceloporus aeneus aeneus~ Wiegmann _Sceloporus aeneus_ Wiegmann, Isis von Oken, 21:370, 1828.--México. Type locality restricted to Tres Cumbres, Morelos, México, by Smith and Taylor (1950b:137). _Sceloporus aeneus aeneus_, Smith, Occ. Pap. Mus. Zool. Univ. Michigan, 361:6, December 15, 1937. Angahuan; Araparicuaro (2); Capácuaro (2); Carapan (11); Cherán (11); 18 km. WNW of Ciudad Hidalgo (10); Cuseño Station; Jeráhuaro; Los Conejos (36); Macho de Agua (7); Opopeo; Paracho (2); Pátzcuaro (4); Pino Gordo; 18 km. W of Quiroga (2); Tancítaro (49); Uruapan (14); 16 km. NW of Zacapu (5); between Zacapu and Zamora (2); 13 km. E of Zinapécuaro; 14 km. SE of Zitácuaro (14). This small terrestrial species inhabits the pine and fir forests of the Cordillera Volcánica between elevations of 1850 and 3100 meters; apparently it is absent from the Sierra de Coalcomán. It seems to prefer rather open coniferous forests in which there is a more or less continuous cover of grasses on the ground. On warm sunny days the lizards can be observed scurrying about in the grass; in the early hours of the day, or on cold days, they are found beneath stones, logs, or dead clumps of bunch grass. ~Sceloporus asper~ Boulenger _Sceloporus asper_ Boulenger, Proc. Zool. Soc. London, 1897:497, October, 1897.--La Cumbre de los Arrastrados, Jalisco, México. Apatzingán (3); 10 km. E of Dos Aguas; Uruapan (41). This strictly arboreal lizard is abundant in the mixed broad-leafed forest near Uruapan. The lizards are exceedingly wary and can be approached only with difficulty. In life males have pale blue bellies; the throat is pale pink. The pale gray dorsum marked with irregular darker gray blotches blends well with the color of the tree trunks on which the lizard lives. The one specimen from Dos Aguas was found on a pine tree; it provides the only record for the species from the Sierra de Coalcomán. ~Sceloporus bulleri~ Boulenger _Sceloporus bulleri_ Boulenger, Proc. Zool. Soc. London, 1894:729, April, 1895.--Las Cumbre de los Arrastrados, Jalisco, México. Acuaro de las Lleguas (13); Barolosa (9); Dos Aguas (61); 10 km. NE of Dos Aguas (5). Heretofore this species has been known only from a few specimens from scattered localities in the Sierra Madre Occidental in southwestern Jalisco and Sinaloa. The collection of a large series of these lizards in virgin pine forest at elevations of more than 2000 meters in the Sierra de Coalcomán now makes possible an analysis of variation in the species. Superficially _S. bulleri_ resembles _S. torquatus_, but _S. bulleri_ is smaller, has more dorsal scales, fewer scales in the dark collar, and fewer femoral pores. In 88 specimens of _S. bulleri_ there are 36-41 (38.7) dorsal scales and 2 or 3 (2.6) middorsal scales in the collar, as compared with 28-31 (29.3) dorsal scales and 3 or 4 (3.4) middorsal scales in the collar of 26 specimens of _S. torquatus_ from Uruapan. In 20 adult males of _S. bulleri_ there are 13-15 (14.3) femoral pores, and 13-16 (14.4) in 11 females; 13 males of _S. torquatus_ have 14-21 (17.3) femoral pores, and 13 females have 15-21 (16.7). Seventeen adult males of _S. bulleri_ have snout-vent lengths of 72-91 (82.0); ten females, 71-87 (75.7). In comparison, 13 adult males of _S. torquatus_ have an average snout-vent length of 88.9 mm., and 13 females, 88.5 mm. In _S. bulleri_ there is little variation in the head scales. The frontal is in contact with the interparietal in 63, and not in 24, specimens; the median frontonasal is in contact with the frontal in 13, and not in 74, specimens. In 39 specimens there are two canthals, and in 48 there is one; in 29 specimens there are three preauriculars, and in 58 there are four. In life adult males have a pale blue tail, bright blue belly patches, a purplish blue throat, and pale blue lines on the sides of the head and neck. This species was obtained at four localities in the high mountains of the Sierra de Coalcomán. In this mountain range _Sceloporus bulleri_ apparently replaces _S. torquatus_, a species that is widespread in the Cordillera Volcánica and on the Mexican Plateau. At Dos Aguas and at Acuaro de las Lleguas the lizards were abundant in the tall pine forest, where they were found on standing pine trees, on pine logs, and on rock outcroppings. ~Sceloporus dugesi intermedius~ Dugès _Sceloporus intermedius_ Dugès, La Naturaleza, 4:29, 1877.--La Noria, near Zamora, Michoacán, México. _Sceloporus dugesii intermedius_, Smith, Univ. Kansas Sci. Bull., 24:663, February 16, 1938. Cojumatlán (6); Jiquilpan (11); Lago de Camécuaro; Lago de Chapala; Morelia (23); Pátzcuaro (84); Quiroga (35); Sahuayo (4); Tacícuaro (2); Tangamandapio (17); Tangancícuaro (9); Zacapu (4); Zamora (11); Zinapécuaro (9). This lizard is strictly an inhabitant of the Mexican Plateau, where it is found in rocky places, sometimes in pine-oak forest, but more frequently in mesquite-grassland. It is a terrestrial species, and is most often seen on rock fences at elevations of 1500 to 2200 meters. This species differs from _S. bulleri_ and _S. torquatus_ in having two rows of supraoculars, instead of one; also it has more dorsal scales. Twenty-six specimens of _Sceloporus dugesi intermedius_ from Tangamandapio and Tangancícuaro have 44-48 (45.7) dorsal scales, as compared with an average of 38.7 in _S. bulleri_ and 29.3 in _S. torquatus_. In life _Sceloporus dugesi intermedius_ has a dull greenish gray dorsum; in males the belly patches are bright blue bordered medially by black, and the throat is bluish gray. The largest specimen examined is a male having a snout-vent length of 80 mm. ~Sceloporus gadowae~ Boulenger _Sceloporus gadoviae_ Boulenger, Proc. Zool. Soc. London, 1905, 2:246, October 7, 1905.--Mezquititlán, Guerrero, México. Chupio; El Sabino (77); La Playa (6); Río Marquez, 10 km. S of Lombardia (11). Although this species has a rather extensive range in the Balsas-Tepalcatepec Basin in the state of Michoacán, Guerrero, Morelos, and Puebla, it is only locally abundant in that area. Usually these lizards are found on rocky cliffs in which there are many crevices for cover. _Sceloporus gadowae_ is abundant on a conglomerate cliff along the Río Marquez south of Lombardia. Although the closely related _S. pyrocephalus_ is abundant in the stream valley and in the hills above the cliff, _S. gadowae_ has been found only on the cliff; few individuals of _S. pyrocephalus_ have been observed on the cliff. A similar situation was discovered on a much more extensive conglomerate cliff along the Río Balsas near Mexcala, Guerrero. Near Tehuitzingo, Puebla, where _S. pyrocephalus_ was not found, _S. gadowae_ was found on conglomerate cliffs. Probably there is strong competition between the two species; possibly this has resulted in the restriction of _S. gadowae_ to isolated cliff-habitats within the extensive range of the more widespread _S. pyrocephalus_. In Michoacán _Sceloporus gadowae_ has been found along the lower slopes of the Cordillera Volcánica at elevations from 250 to 1050 meters. All of the localities from which this lizard is known lie in the arid tropical scrub forest. ~Sceloporus grammicus microlepidotus~ Wiegmann _Sceloporus microlepidotus_ Wiegmann, Herpetologia Mexicana, p. 51, 1834.--México. Type locality restricted to México, Distrito Federal, by Smith and Taylor (1950b:120). _Sceloporus grammicus microlepidotus_, Smith and Laufe, Trans. Kansas Acad. Sci., 48:332, December, 1945. Angahuari; Apo (10); Atzimba (3); Carapan (5); Cerro San Andrés (17); Cerro Tancítaro (18); Corupu; Cuseño Station (2); Jacona; Jeráhuaro (10); Macho de Agua; Mil Cumbres; 46 km. E of Morelia; 60 km. E of Morelia (2); Opopeo (14); Pátzcuaro (30); Puerto Hondo (19); San Gregorio (41); San José de la Cumbre (8); Sierra Patamba; Tancítaro (233); Tupátaro; Undameo; Uruapan (180); between Zacapu and Zamora; 24 km. SE of Zitácuaro; between Zurumbeneo and Cerro Garnica. This small species of _Sceloporus_ is an ubiquitous inhabitant of the coniferous forests from 1550 to 3100 meters in the Cordillera Volcánica. Usually it is seen on tree trunks, but occasionally on the ground. Near the lower limit of the altitudinal distribution of the species, as at Uruapan, individuals sometimes are found on broad-leafed trees. Apparently _Sceloporus heterolepis_ replaces _S. grammicus microlepidotus_ in the Sierra de Coalcomán. ~Sceloporus heterolepis~ Boulenger _Sceloporus heterolepis_ Boulenger, Proc. Zool. Soc. London, 1894:731, April, 1895.--La Cumbre de los Arrastrados, Jalisco, México. Araparicuaro; Cerro Barolosa (6); Dos Aguas (13); Los Conejos; 11 km. N of Uruapan (3). Although Michoacán has not previously been included in the range of this lizard, it was first collected in the state by Gadow in 1908 (BMNH 1914.1.28.69 from Araparicuaro). The description of _S. heterolepis_ given by Smith (1939:197) can be supplemented by data on the 23 specimens now in the collections of the Museum of Zoology at the University of Michigan. All have two canthals; there are 55 to 71 (63.6) scales in the middorsal row; 1 to 3 rows middorsally are somewhat enlarged and bordered on either side by a row of larger scales bearing high keels. There are 14 to 20 (16.2) femoral pores. Eight adult males have snout-vent lengths from 49 to 61 (58.0) mm. and tail lengths from 57 to 74 (66.0) mm.; four adult females have snout-vent lengths from 52 to 57 (55.2) mm. and tail lengths from 60 to 66 (63.5) mm. The smallest of eight juveniles has a snout-vent length of 28 mm. and a tail length of 32 mm. The dorsum in adults is pale grayish brown; there are three irregular chevron-shaped dark marks and a triangular dark brown mark above the insertion of the hind limbs; on the tail are dark brown rings. There are scattered faint blue flecks on the flanks and narrow transverse dark lines on the lower limbs. Males have pale bluish green belly patches and an orange-salmon-colored throat; the belly in females is pale orange-tan. The juveniles have a more contrasting color pattern; the dark chevrons on the dorsum are bordered posteriorly by pale gray. In Michoacán this species has been obtained in pine and pine-fir forests from 1800 to 2700 meters. On Cerro Barolosa and at Dos Aguas, both in the Sierra de Coalcomán, the lizards were found beneath the bark of dead, standing pines. In the Sierra de Coalcomán _Sceloporus heterolepis_ seems to fill the niche of the small arboreal _Sceloporus_ in the coniferous forest in southwestern México, a position held by _S. grammicus microlepidotus_ in the Cordillera Volcánica; the latter species does not occur in the Sierra de Coalcomán. Five specimens of _Sceloporus heterolepis_ are known from the Cordillera Volcánica, whereas 603 of _S. grammicus microlepidotus_ have been collected there. The ecological relationships that exist between the two species in the Cordillera Volcánica are not known. Insofar as is known, _Sceloporus heterolepis_ reaches the southern limits of its range in the Sierra de Coalcomán and in the western part of the Cordillera Volcánica. Other records for the species are from the Sierra Madre Occidental in Jalisco. Langebartel (1959) described _Sceloporus shannonorum_ from the mountains near the Durango-Sinaloa border; the single specimen of _S. shannonorum_ differs significantly from _S. heterolepis_ only in having fewer dorsal scales (48). The acquisition of additional material, especially from Nayarit and northern Jalisco, probably will provide a basis for showing that these two populations are conspecific. ~Sceloporus horridus oligoporus~ Cope _Sceloporus oligoporus_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:177, September 30, 1864.--Colima, Colima, México. _Sceloporus horridus oligoporus_, Taylor, Univ. Kansas Sci. Bull., 24:520, February 16, 1938. Aguililla; Apatzingán (50); Arteaga (2); Capirio (2); Cascada Tzararacua; Charapendo (4); Coahuayana (3); Coalcomán (32); 19 km. S of Corralito; 27 km. E of Dos Aguas; El Sabino (55); El Ticuiz; Huetamo (2); Jazmin; Jungapeo (2); La Orilla (2); La Placita; Limoncito (3); Playa Azul (5); Tzitzio (8); Uruapan (4); Volcán Jorullo (2); Ziracuaretiro; Zirimícuaro (13). All of the specimens from Michoacán seem to be typical _S. horridus oligoporus_; none has more than six femoral pores. Characteristically this species is found in open arid scrub forest; it reaches its greatest abundance in rocky areas in which there are scattered leguminous trees and bushes. It has been found in these low trees and bushes almost as frequently as it has been found on the ground; none has been seen in large trees or far above the ground. Altitudinally, this species ranges from sea level to about 1600 meters. ~Sceloporus melanorhinus calligaster~ Smith _Sceloporus melanorhinus calligaster_ Smith, Proc. U. S. Natl. Mus., 92:360, November 5, 1942.--Acapulco, Guerrero, México. Aguililla; Apatzingán (18); Barranca de Herradero; Capirio (19); Coahuayana (4); Coalcomán (2); Cofradía (4); El Cerrito; El Sabino (33); El Ticuiz (3); La Placita (6); Lombardia (4); Playa Azul; Río Marquez, 10 km. S of Lombardia (2); Río Marquez, 13 km. SE of Nueva Italia (4); Salitre de Estopila; San Juan de Lima (2); Santa Ana; Tzitzio; Ziracuaretiro. Smith (1942a:360) diagnosed _Sceloporus melanorhinus calligaster_ as having fewer femoral pores than the other subspecies of _S. melanorhinus_ and as having the lateral belly patches in the males confluent in the midline. Examination of forty specimens from the Tepalcatepec Valley and the coastal regions of Michoacán does not substantiate this diagnosis. The number of femoral pores varies from 15 to 22 (18.9); 14 individuals (35%) had 20 or more femoral pores. Smith (_loc. cit._) stated that _S. melanorhinus_ in Oaxaca had 18 to 27 (21.6) femoral pores and that 77 per cent of the specimens had more than 20 femoral pores. Of the 24 males examined from Michoacán, 18 have the lateral belly patches separated in the midline. Usually they are separated by no more than one scale, but in some individuals they are separated by two or more scales. Although the above data minimize certain differences between the northern and southern populations of this species, certain of the color pattern characters seem to be diagnostic of the subspecies inhabiting the Pacific lowlands from Guerrero to Nayarit. Large adults of _S. m. calligaster_ have only a faint dorsal pattern, which in the subspecies _melanorhinus_ and _stuarti_ consists of a series of large, dark, interconnected triangles on the back. This pattern is present in young and small adults of _S. m. calligaster_; furthermore, in this subspecies the ventral coloration of the males differs from that found in the more southern populations. Adult males of _S. m. calligaster_ have a black throat, that changes to brilliant blue posteriorly, and a large white spot medially on the chin. This spot is present in some specimens from Oaxaca and Chiapas, but, if present, it is much smaller and less distinct than in specimens from Michoacán. In _S. m. calligaster_ the chest and midventral area are orange to salmon-color. A male from Lombardia in life was colored as follows: Dorsum grayish tan bearing faint bluish gray flecks; chest deep salmon-orange, this color continuing down midventral area to the somewhat paler groin; belly patches pale blue fading to pale green laterally; throat black anteriorly enclosing a white spot; throat blue posteriorly and bluish green posterolaterally. Individual lizards were observed to change in dorsal color from a pale ashy gray to a rather dull brown. Normally, inactive individuals and those observed on overcast days were dull brown. _Sceloporus melanorhinus calligaster_ is found in trees in riparian situations in the lowlands to elevations of about 1500 meters. It does not inhabit the arid tropical scrub forest in the Tepalcatepec Valley or on the coast, but in those areas is found in the gallery forests along streams and rivers. The lizards are wary and live high in the trees; they are especially difficult to locate in the rainy season, when the trees are in full leaf. ~Sceloporus pyrocephalus~ Cope _Sceloporus pyrocephalus_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:177, September 30, 1864.--Colima, Colima, México. Acahuato (2); Apatzingán (142); Arteaga (4); 26 km. S of Arteaga (4); Capirio (6); Chinapa; Chupio; 19 km. S of Corralito (5); El Sabino (220); Jazmin (3); La Placita (8); La Playa (14); La Salada (6); Lombardia (5); Nueva Italia (14); Ojos de Agua de San Telmo (2); Oropeo (3); Ostula; Punta de San Telmo (3); Río Cancita, 14 km. E of Apatzingán (13); Río Marquez, 10 km. S of Lombardia (10); Río Marquez, 13 km. SE of Nueva Italia (3); San Juan de Lima (2); Santa Ana (2); Tafetan (2); Tepalcatepec (2); Tzitzio (6); Volcán Jorullo (3). This small species is extremely common in the Tepalcatepec Valley and noticeably less so on the coast. It is usually found on the ground in rocky areas, but males frequently have been seen on the trunks of low trees in the scrub forest. Altitudinally, it ranges from sea level to slightly more than 1000 meters. The sexes are readily distinguished in the field (Oliver, 1937; Smith, 1939; Duellman, 1954b). In the dry season only males were observed in the Tepalcatepec Valley, but in the rainy season both sexes were found in approximately the same numbers. ~Sceloporus scalaris scalaris~ Wiegmann _Sceloporus scalaris_ Wiegmann, Isis von Oken, 21:370, 1828.--México. Type locality restricted to México, Distrito Federal, by Smith and Taylor (1950b:137). _Sceloporus scalaris scalaris_, Smith, Occ. Pap. Mus. Zool. Univ. Michigan, 361:2, December 15, 1937. Carapan (2); Cherán; Ciudad Hidalgo; Huingo (3); Jacona (3); Jiquilpan (2); Lago de Camécuaro (2); Lago de Chapala; Lago de Cuitzeo (5); Morelia (4); Pátzcuaro (4); Queréndaro; Quiroga; Tacícuaro (5); Tarécuaro; Zacapu (4); Zamora (4); Zinapécuaro (11). This small terrestrial species does not seem to be abundant anywhere in the state. It sometimes is found in open pine, oak, or pine-oak forest, but usually it is observed in areas supporting bunch grass. In such places the lizards sun and forage on the open ground and quickly take refuge in the large clumps of grass. Altitudinally, the species ranges from 1550 to 2300 meters. Although _Sceloporus scalaris scalaris_ has been found in association with _S. dugesi intermedius_, _S. spinosus_, and _S. torquatus_, it does not seem to form any close ecological association with any of these species. In the pine forests of the Cordillera Volcánica _S. s. scalaris_ is replaced by _Sceloporus aeneus aeneus_, another small terrestrial species that occurs in great abundance throughout the coniferous forests of the Cordillera Volcánica. ~Sceloporus siniferus siniferus~ Cope _Sceloporus siniferus_ Cope, Proc. Amer. Philos. Soc., 11:159, 1869.--Pacific side of the Isthmus of Tehuantepec. Type locality restricted to Tehuantepec, Oaxaca, México, by Smith and Taylor (1950b:134). _Sceloporus siniferus siniferus_, Smith and Taylor, Bull. U. S. Natl. Mus., 199:134, October 26, 1950. Twenty-six km. S of Arteaga; Barranca de Bejuco (2); Coahuayana; El Ticuiz (2); La Mira; La Orilla (2); La Placita (9); Maruata; Ojos de Agua de San Telmo; Ostula (4); Playa Azul (6); Pómaro (2); Puerto de las Higuerita; Santa Ana (3). This small terrestrial species inhabits the dense arid tropical scrub forest on the coast and lower foothills of the Sierra de Coalcomán to elevations of about 150 meters. It also occurs in the lower Balsas Valley, but it has not been found in the scrub forest of the broad Tepalcatepec Valley. Perhaps the large number of _Sceloporus siniferus_ on the coastal lowlands is responsible for the small number there of _S. pyrocephalus_, another terrestrial species of about the same size. The latter is abundant in the Tepalcatepec Valley, where _S. siniferus siniferus_ has not been found. _Sceloporus siniferus siniferus_ is a fast runner and difficult to collect; consequently, the small number of specimens available is not indicative of its abundance. ~Sceloporus spinosus spinosus~ Wiegmann _Sceloporus spinosus_ Wiegmann, Isis von Oken, 21:370, 1828.--México. Type locality restricted to Puebla, Puebla, México, by Smith and Taylor (1950b:116). _Sceloporus spinosus spinosus_, Martín del Campo, Anal. Inst. Biol. México, 8:262, 1937. Cojumatlán (2); Huetamo Road; Lago de Cuitzeo (4); Maravatio (8); Tupátaro (2). Although this species is widespread on the southern part of the Mexican Plateau, it is uncommon in Michoacán. It has been collected only in rather open situations in the mesquite-grassland on the plateau between 1500 and 2300 meters, where it has been found in association with _Sceloporus dugesi intermedius_ and _S. scalaris scalaris_. Most specimens of _Sceloporus spinosus spinosus_ have been observed on rock fences. In this habitat the species is the larger member of a pair of species, the smaller of which is _Sceloporus dugesi intermedius_. ~Sceloporus torquatus torquatus~ Wiegmann _Sceloporus torquatus_ Wiegmann, Isis von Oken, 21:369, 1828.--México. Type locality restricted to México, Distrito Federal, by Smith and Taylor (1950b:126). _Sceloporus torquatus torquatus_, Cope, Proc. Amer. Philos. Soc., 22:402, 1885. Angahuan (31); Araparicuaro; Capácuaro (3); Carapan (11); Cerro Tancítaro; Cherán; Ciudad Hidalgo; Cojumatlán; Copándaro (2); Corupu (4); Cuseño Station (9); El Álamo; Jacona (6); Jiquilpan (2); Jungapeo (3); Lago de Camécuaro; Lago de Chapala; Lago de Cuitzeo (3); La Palma (2); Los Conejos (3); Los Reyes (3); Maravatio (9); Morelia (17); Paracho (3); Pátzcuaro (27); Pino Gordo; Queréndaro (2); Quiroga; Sahuayo (3); San José de la Cumbre; San Juan de Panangaricutiro; Tacícuaro (10); Tancítaro (200); Tangamandapio; Tangancícuaro (3); Temazcal (2); Tupátaro (5); Uruapan (136); Zacapu; Zinapécuaro (10); Zirimícuaro (12); Zitácuaro. This large species inhabits the Mexican Plateau and the Cordillera Volcánica, but not the Sierra de Coalcomán, where apparently it is replaced by _Sceloporus bulleri_. _Sceloporus torquatus torquatus_ usually is found in pine or pine-fir forests at elevations between 1450 and 3000 meters. In many places it is almost entirely arboreal, but in areas where there are many fallen trees or rock fences and rock piles, many individuals have been found on the ground near the rocks or logs. In the coniferous forests this species is associated with _S. grammicus microtepidotus_ and _S. aeneus aeneus_. The distinction made by Smith (1938:572) between the subspecies _S. torquatus torquatus_ and _melanogaster_ is slight. Individuals with pale bluish spots are found throughout the range of the species in Michoacán; spotting is especially evident in the young. Individuals having an incomplete nuchal collar have been found at Maravatio and at Zinapécuaro in the northern part of the state; in this character these specimens resemble _S. torquatus melanogaster_, which is found to the north from Guanajuato to Zacatecas and San Luis Potosí. ~Sceloporus utiformis~ Cope _Sceloporus utiformis_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:177, September 30, 1864.--Colima, Colima, México. Nineteen km. S of Arteaga (2); Cascada Tzararacua (17); Coahuayana (3); Coalcomán (6); El Sabino (2); El Ticuiz (2); Ostula (3); Pómaro; Río Cachán; San Juan de Lima; Uruapan (26). In Michoacán the range of this species is discontinuous. It has been found between 1050 and 1550 meters on the slopes of the Cordillera Volcánica, and on the coast and seaward slopes of the Sierra de Coalcomán up to an elevation of 900 meters. It is absent from the Tepalcatepec Valley. At Uruapan and at Cascada Tzararacua this lizard was found on the ground in oak forest or in open pine-oak forest; on the coast and foothills of the Sierra de Coalcomán it was found on the ground in the gallery forests along streams, and not in the scrub forest. ~Urosaurus bicarinatus tuberculatus~ (Schmidt) _Uta tuberculata_ Schmidt, Amer. Mus. Novitates, 22:4, December 1, 1921.--Colima, Colima, México. _Urosaurus bicarinatus tuberculatus_, Mittleman, Bull. Mus. Comp. Zool., 91:169, September, 1942. Twenty-six km. S of Arteaga; Cascada Tzararacua (2); Chupio; Coahuayana; Coalcomán (8); El Sabino (2); Jungapeo; La Orilla (2); La Placita (4); Playa Azul (4); Pómaro (2); San Salvador (16);? Tupátaro; Uruapan (12); Tzitzio; Zamora. The known distribution and geographic variation of _Urosaurus bicarinatus_ in southwestern México presents a confused picture. In general rugosity, specimens from the coastal region of Michoacán (Coahuayana, La Orilla, La Placita, Playa Azul, and Pómaro) resemble _U. bicarinatus tuberculatus_ to the north along the Pacific coast. Furthermore, specimens from the coast have less stippling in the gular region than do those from the Sierra de Coalcomán and the slopes of the Cordillera Volcánica. Specimens from the mountains have greatly carinate enlarged dorsals, large lateral tubercles, and heavily stippled throats; in these characters they resemble specimens from Morelos, Guerrero, and Oaxaca. As mentioned by Peters (1954:14), some specimens from La Orilla and San Salvador are like _U. bicarinatus bicarinatus_ in certain characters, and one specimen has the blue ventral patches restricted to the sternal area, a characteristic of _U. bicarinatus anonymorphus_ of Oaxaca and eastern Guerrero. Examination of all available specimens from Michoacán indicates that the nature of the dorsal scales is of little value in separating the subspecies. The specimens from Michoacán are here provisionally referred to _U. bicarinatus tuberculatus_, because cursory examination of specimens from several localities between Nayarit and Oaxaca shows that there are only minor differences between the named populations. Individuals from the northern part of the range are more rugose and have larger blue ventral patches and less gular stippling than those from the south. In Michoacán _Urosaurus bicarinatus tuberculatus_ is found in wooded areas, not in open scrub forest, in the coastal area to elevations of about 900 meters, and along the slopes of the Cordillera Volcánica and the southern edge of the Mexican Plateau at elevations from 1000 to 1700 meters. The record for Tupátaro probably is erroneous, for no other specimens of this species are known from the central plateau. Essentially, the distribution of this species parallels that of _Sceloporus utiformis_, a strictly terrestrial species. _Urosaurus bicarinatus tuberculatus_ lives on tree trunks. Below 1000 meters in the Tepalcatepec Valley _Urosaurus bicarinatus tuberculatus_ is replaced by _Urosaurus gadowi_. ~Urosaurus gadowi~ (Schmidt) _Uta gadovi_ Schmidt, Amer. Mus. Novitates, 22:3, December 1, 1921.--Cofradía, Jalisco, México (in error) = Cofradía, Michoacán, México (Duellman, 1958b:49). _Urosaurus gadowi_, Mittleman, Bull. Mus. Comp. Zool., 91:154, September, 1942. Acahuato (2); Apatzingán (56); 12-16 km. S of Apatzingán (12); Buenavista (7); Capirio (23); Cofradía (21); El Sabino (13); Guayabo; Jazmin; La Playa; La Salada (3); Nueva Italia (7); Rancho Nuevo; Río Cancita, 14 km. E of Apatzingán (5); Río Marquez, 10 km. S of Lombardia (2); Río Marquez, 13 km. SE of Nueva Italia (3); San Salvador (2); Santa Ana; Tepalcatepec; Volcán Jorullo (3); Zicuiran (2); Ziracuaretiro. Although individuals of this species have been collected at elevations slightly exceeding 1200 meters on Volcán Jorullo and at 1100 meters at Ziracuaretiro on the southern slopes of the Cordillera Volcánica, for the most part these lizards are found at elevations of less than 800 meters, where they inhabit the open arid scrub forest of the Tepalcatepec Valley, a region to which this species is endemic (Duellman, 1958b:49). These small lizards usually are found on the trunks and main branches of the small trees in the scrub forest; in this habitat they are associated with _Sceloporus horridus oligoporus_, a much larger species. Males have a pale orange spot on the throat and a pale blue belly; females have immaculate venters. A specimen from Guayabo on the northern slopes of the Sierra de Coalcomán was referred to _Urosaurus irregularis_ (Fischer) by Peters (1954:15). I have studied this specimen (BMNH 1914.1.28.110), a female having a snout-vent length of 46 mm., and agree with Peters that it closely resembles Fischer's description and figure (1882: pl. 17, fig. 1). This specimen and those seen of _Urosaurus gadowi_ all have pavementlike enlarged dorsal scales that are complete across the vertical line. In _U. gadowi_ the enlarged dorsals usually are in four to six irregular rows; in the specimen from Guayabo the dorsals are in two rows. Although none of the other specimens of _U. gadowi_ examined has only two rows of enlarged dorsals, I prefer to consider the specimen from Guayabo as an aberrant individual of that species, rather than _U. irregularis_. Guayabo is in the known range of _U. gadowi_. _Urosaurus irregularis_ is known only from the type specimen in the Bremen Museum; the type locality, according to Fischer (1882:232), is "Aus dem Hochlande von Mexico." If an examination of the type specimen of _U. irregularis_ shows it to be identical with _U. gadowi_, then _U. irregularis_ would be the name for the lizards here referred to _U. gadowi_. ~Mabuya brachypoda~ Taylor _Mabuya brachypoda_ Taylor, Univ. Kansas Sci. Bull., 38 (1):308, December 20, 1956.--Four kilometers east-southeast of Los Angeles de Tilarán, Guanacaste, Costa Rica. El Sabino (42); La Placita; Playa Azul; Tzitzio (3). Previously this species has been reported from La Placita as _Mabuya mabouya alliacea_ by Peters (1954:15). Webb (1958:1311) provided evidence that Mexican specimens were conspecific with _Mabuya brachypoda_, as described from Costa Rica by Taylor (1956:308). The large series in the Taylor collection studied by Webb and listed by him as being from Uruapan actually is part of a series collected by Hobart M. Smith at El Sabino at an elevation of 1050 meters, 30 kilometers south of Uruapan. This species probably ranges throughout the coastal region of the state; individuals from La Placita and Playa Azul were taken in dense scrub forest near sea level. ~Scincella assata taylori~ (Oliver) _Leiolopisma assatum taylori_ Oliver, Occ. Pap. Mus. Zool. Univ. Michigan, 360:12, November 20, 1937.--Santiago, Colima, México. _Scincella assata taylori_, Mittleman, Herpetologica, 6:20, June 5, 1950. Twenty-one km. S of Arteaga; Ostula. The specimen from Ostula was obtained in semi-deciduous broad-leaf forest at an elevation of 120 meters; that from 21 kilometers south of Arteaga was taken in oak forest at an elevation of 830 meters. Both localities are on the coastal slopes of the Sierra de Coalcomán. Probably the species inhabits the heavy forests on the lower slopes of these mountains. The specimen from south of Arteaga (UMMZ 119117) in life had a tan dorsum and a bright orange-pink tail. ~Eumeces altamirani~ Dugès _Eumeces altamirani_ Dugès, La Naturaleza, ser. 2, 1:485, 1891.--Apatzingán, Michoacán, México. Twelve km. E of Apatzingán; El Sabino (4). One specimen of this rare species was found beneath a rock in the open scrub forest 12 kilometers east of Apatzingán on July 3, 1955. Another skink, presumably of this species, was seen at Capirio. The specimen from east of Apatzingán is a male having a snout-vent length of 97 mm. and an incomplete tail. In most respects it compares favorably with accounts of the species given by Taylor (1936b:55 and 1936c:102). The frontal is divided by a transverse suture; the enlarged dorsal scales are arranged in 11 pairs anteriorly, followed by 48 unpaired enlarged scales. The head and middorsal area are brown; there is a pale tan stripe on the edges of the vertebral and paravertebral rows, bordered by a dark brown stripe on the paravertebral row, which, in turn, is bordered by a pale tan stripe on the lateral edge of the paravertebral scale row and the median edge of the adjacent scale row. The stripes extend from the neck to the base of the tail. The flanks are mottled with brown and cream-color; the labials are cream-color barred by brown; the venter is a pale cream-color. Dugès (1891:485) described _Eumeces altamirani_ from "las regiones cálidas del Estado de Michoacán" and subsequently (1896:480) gave Apatzingán as a locality for the species. Presumably he had only one specimen. In 1935 Hobart M. Smith collected the species at El Sabino on the lower slopes of the Cordillera Volcánica bordering the Tepalcatepec Valley. All of the known specimens are from this valley and the adjacent slopes, an area to which the species apparently is endemic. ~Eumeces colimensis~ Taylor _Eumeces colimensis_ Taylor, Publ. Field Mus. Nat. Hist., zool. ser., 20:77, May 15, 1935.--Colima, Colima, México. Coalcomán; Salitre de Estopila. The species was reported by Peters (1954:16); no additional material has been discovered. The species is known only from foothills and low mountains at elevations between 130 and 950 meters in Michoacán and Colima. ~Eumeces copei~ Taylor _Eumeces copei_ Taylor, Proc. Biol. Soc. Washington, 46:133, June 5, 1933.--10 miles southeast of Asunción, México, México. Cerro Tancítaro (3); Zacapu. This member of the _Eumeces brevirostris_-group has been found only in pine or pine-fir forests at elevations from 1800 to 2700 meters. It probably ranges throughout the high mountains of the state north of the Tepalcatepec Valley; its apparent absence in other parts of the Cordillera Volcánica, other than on Cerro Tancítaro, is surprising. The species has been taken near Asunción in the state of México and at Lagunas de Zempoala in Morelos. In this species the lateral pale yellow stripe, which is bordered below by dark brown, extends to the groin and onto the base of the tail. The dorsolateral stripe is separated from the copper-colored middorsum by a narrow brown stripe. ~Eumeces dugesi~ Thominot _Eumeces Dugesii_ Thominot, Bull. Soc. Philom. Paris, ser. 7, 7:138, 1883.--Guanajuato. Type locality restricted to Guanajuato, Guanajuato, México, by Smith and Taylor (1950b:169). Carapan (6); Cherán (5); Opopeo (2); 17 km. S of Pátzcuaro (3); San José de la Cumbre (2); Tancítaro (2); Tangancícuaro; Uruapan; Zacapu. Individuals of this species frequently have been found beneath rocks and logs in pine-oak, pine, or fir forests from elevations of 1550 to 1850 meters. To judge from specimens available, _E. dugesi_ probably is the most abundant and widespread species of skink in the state. In this species the lateral yellow stripe is indistinct and is persistent only in the axilla; the dorsolateral stripes terminate anterior to the hind limbs and are not separated from the tan dorsum. ~Eumeces indubitus~ Taylor _Eumeces indubitus_ Taylor, Univ. Kansas Sci. Bull., 21:257, November 27, 1934.--Near Cuernavaca, Morelos, México. Puerto Hondo. The one specimen of this species from Michoacán was collected by Edward H. Taylor in pine forest at Puerto Hondo, near Zitácuaro, at an elevation of about 2750 meters (Taylor, 1935:466). The species is known from the high mountains of eastern Michoacán, western México, and northern Morelos. ~Eumeces parvulus~ Taylor _Eumeces parvulus_ Taylor, Proc. Biol. Soc. Washington, 46:175, October 26, 1933.--Tepic, Nayarit, México. El Ticuiz; La Placita; Pómaro (2); San Pedro Naranjestila (3). Aside from the specimens reported by Peters (1954:17), one other specimen was obtained at El Ticuiz. It has 22 scale rows, 3 supraoculars in contact with the frontal, 2 postlabials, and a unicolored olive-tan dorsum. In life the anterior dorsolateral stripes were pale pinkish tan, the labials cream color, the throat white, and the tail pale blue. All specimens were found in semi-deciduous broad-leaf forest at elevations of less than 500 meters on the seaward slopes of the Sierra de Coalcomán. ~Ameiva undulata sinistra~ Smith and Laufe _Ameiva undulata sinistra_ Smith and Laufe, Univ. Kansas Sci. Bull., 31 (1):59, May 1, 1946.--Manzanillo, Colima, México. Apatzingán (9); 19 km. S of Arteaga (3); Barranca de Bejuco (2); Coahuayana (6); Coalcomán (3); El Ticuiz (10); La Placita (2); Limoncito (3); Ostula (2); Playa Azul; Salitre de Estopila; San Juan de Lima (2); San Pedro Naranjestila (4). Six males and six females from the Tepalcatepec Valley have more femoral pores than do 16 males and nine females from the coastal lowlands; the ranges and average number of femoral pores in the former are 40-50 (44.8) for males and 38-40 (38.6) for females; males from the coast have 34-44 (39.2), and females have 32-40 (36.2) femoral pores. In all specimens the number of lamellae beneath the fourth toe varies from 26 to 33 (29.7). In life juveniles have a pale olive-tan dorsum and a dorsolateral dark band, superimposed on which is a row of darker brown spots. The dorsolateral band is bordered below by a narrow cream-colored stripe. The tail is tan above and grayish white below; the belly is pale bluish white. Adult males are brilliantly colored in life. A male having a snout-vent length of 108 mm. had a rusty brown dorsum and bright blue bars on the flanks separated by dark brown interspaces. The side of the head was pale green, and the chin and throat were golden yellow. In some specimens the throat is orange. Juveniles and subadults have dark flecks on the brown or tan middorsal area, but these are absent in the largest males. This species inhabits the heavily wooded areas in the lowlands to elevations of about 950 meters. In the Tepalcatepec Valley it has been found only in gallery forests along streams. In both the Tepalcatepec Valley and the coastal lowlands there is a noticeable absence of large adults in the dry season. ~Cnemidophorus calidipes~ Duellman _Cnemidophorus calidipes_ Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 574:1, December 23, 1955.--Capirio, Michoacán, México. Apatzingán (56); 12-20 km. S of Apatzingán (5); 19 km. E of Apatzingán (5); 25 km. S of Arteaga; Capirio (57); El Espinal (13); Jazmin (9); 11 km. S of Lombardia; Nueva Italia. This small, distinctive species of the _sexlineatus_-group of _Cnemidophorus_ was discovered in the Tepalcatepec Valley in 1955 (Duellman, 1955); subsequent field studies showed it to be widespread in the valley (Duellman, 1960c). One specimen (KU 29747) is from the relatively arid, low Pacific slope of the Sierra de Coalcomán, 25 kilometers south of Arteaga. All other specimens have been taken at elevations of 200 to 650 meters in the Tepalcatepec Valley, where the species characteristically inhabits the open scrub forests of the valley floor, especially the _Cercidium-Prosopis-Apoplanesia_ associations, where there is a sparse growth of grasses. In this habitat it is most frequently seen in association with _Cnemidophorus costatus zweifeli_ and _C. deppei infernalis_. Aside from the characters given in Table 5, _Cnemidophorus calidipes_ differs from other species of _Cnemidophorus_ in Michoacán by possessing a complete (or nearly so) supraorbital semicircle-series of granules; in other species the granules seldom extend anteriorly beyond the posterior border of the frontal. ~Cnemidophorus communis communis~ Cope _Cnemidophorus communis_ Cope, Proc. Amer. Philos. Soc., 17:95, 1877.--No type locality given; type locality restricted to Colima, Colima, México, by Zweifel (1959a:74). _Cnemidophorus communis communis_, Zweifel, Bull. Amer. Mus. Nat. Hist., 117:74, April 27, 1959. Aguililla (2); Apatzingán (6); 13 km. S of Arteaga (2); 19 km. S of Arteaga (3); Capirio (3); Coahuayana (3); Coalcomán (44); El Ticuiz; between El Ticuiz and Ojos de Agua de San Telmo; La Placita (6); Pómaro (2); Río Cachán; Salitre de Estopila; San Juan de Lima. The specimens from Coalcomán and the coastal localities were referred to _Cnemidophorus sacki copei_ by Peters (1954:18) and Duellman (1954b:12). Zweifel (1959a) referred these specimens to _Cnemidophorus communis communis_ and pointed out the probable sympatry of _C. communis_ and _C. costatus_ (= _sacki_ of Zweifel) in the Tepalcatepec Valley. There is considerable geographic variation in the number of dorsal granules around the midbody. Sixteen specimens from the coastal regions of Michoacán have 129-146 (136.3) granules; nine from the Tepalcatepec Valley have 124-137 (128.3), and 44 from Coalcomán at an elevation of 950 meters in the Sierra de Coalcomán, intermediate geographically between the coast and the Tepalcatepec Valley, have 105-144 (119.7). The number of granules in specimens from the coast of Michoacán compares favorably with the range of 118-154 (137.8) for 34 specimens from Colima, Colima (Zweifel, 1959a:107). Aside from the characters given in Table 5, _C. communis communis_ can be distinguished from other members of the _Cnemidophorus sexlineatus_-group (_calidipes_, _costatus_, and _scarlaris_) by its relatively small post-antebrachial scales. TABLE 5.--COMPARISON OF THE TEN SPECIES AND SUBSPECIES OF CNEMIDOPHORUS IN MICHOACÁN (SCALE COUNTS ARE FOR SPECIMENS FROM MICHOACÁN ONLY) ----------------+--------+-------+------------------+-----------+---------- |Dorsal |Femoral| Adult color | Throat | Maximum Species |granules| pores | pattern | color |snout-vent | | | | | length ----------------+--------+-------+------------------+-----------+---------- _calidipes_ | 66-86 |31-47 |Light brown dorsum| Pink | 79 mm. | (75) |(39) |with vertical blue| | | | |bars and spots | | ----------------+--------+-------+------------------+-----------+---------- _communis |105-146 | 38-52 |Green dorsum with | Pink | 135 mm. communis_ |(124) | (44) |six rows of yellow| | | | |spots | | ----------------+--------+-------+------------------+-----------+---------- _costatus | 97-102 |37-43 |Cross-bars | Pink | 126 mm. occidentalis_ | (99) |(39) |anteriorly and | | | | |pale spots | | | | |posteriorly | | ----------------+--------+-------+------------------+-----------+---------- _costatus |91-117 |32-49 |Lateral and |Pink with | 132 mm. zweifeli_ |(106) |(41) |dorsolateral rows |blue spot | | | |of spots; | | | | |paravertebrals | | | | |fused with pale | | | | |green middorsum | | ----------------+--------+-------+------------------+-----------+---------- _deppei deppei_ |116-117 |37-38 |Green | Black | 93 mm. |(116) |(37) |paravertebral and | | | | |dorsolateral | | | | |stripes; lateral | | | | |stripe broken into| | | | |row of bluish | | | | |spots | | ----------------+--------+-------+------------------+-----------+---------- _deppei |91-120 |31-43 |Green | Black | 84 mm. infernalis_ |(101) |(36) |paravertebral and | | | | |dorsolateral | | | | |stripes; broad | | | | |cream lateral | | | | |stripe; reddish | | | | |flanks | | ----------------+--------+-------+------------------+-----------+---------- _lineatissimus |108-140 |32-47 |Paravertebral |Pink and | 98 mm. exoristus_ |(122) |(39) |stripes fused with|black | | | |yellow middorsal| | | | |stripe; vertical | | | | |bars on flanks | | ----------------+--------+-------+------------------+-----------+---------- _lineatissimus |117-126 |32-37 |Eight distinct |Bluish-pink| 96 mm. lineatissimus_ |(121) |(35) |stripes plus |and black | | | |partially fused | | | | |vertebrals | | ----------------+--------+-------+------------------+-----------+---------- _lineatissimus |126-164 |32-48 |Broad middorsal |Pink and | 106 mm. lividus_ |(148) |(38) |stripe; |black | | | |paravertebrals | | | | |distinct; blue | | | | |lateral spots | | ----------------+--------+-------+------------------+-----------+---------- _scalaris_ | 80-92 |32-41 |Six distinct cream|Orange-pink| 95 mm. | (86) |(35) |stripes; tan spots| | | | |in dark fields | | ----------------+--------+-------+------------------+-----------+---------- Although this is the largest species of _Cnemidophorus_ in Michoacán (adult males attain a snout-vent length of 135 mm.), it is neither widespread nor abundant. On the coastal lowlands it occurs primarily with _Cnemidophorus lineatissimus lividus_. In the coastal lowlands there is little open scrub forest, a type of habitat that seems to be preferred by _C. communis communis_. In the Tepalcatepec Valley, _C. communis communis_ occurs in the open scrub forest with the more abundant large species _C. costatus_ (subspecies _zweifeli_). Only in the scrub forest in the Coalcomán Valley, where no other species of _Cnemidophorus_ occurs, is _C. communis communis_ abundant. ~Cnemidophorus costatus occidentalis~ Gadow _Cnemidophorus communis occidentalis_ Gadow, Proc. Zool. Soc. London, 1906, 1:339, August 23, 1906.--Type locality restricted to Ixtlán, Nayarit, México, by Smith and Taylor (1950b:182). _Cnemidophorus costatus occidentalis_, Zweifel, Copeia, No. 1:98; March 17, 1961. Jiquilpan (4). Only four specimens from the extreme northwestern part of the state are referable to this subspecies. These have 97 to 102 dorsal granules at midbody and lack the blue gular band or spot characteristic of the subspecies in the Tepalcatepec Valley. Probably _C. costatus occidentalis_ ranges throughout the Chapala depression, but to the east it is replaced by _Cnemidophorus scalaris scalaris_. ~Cnemidophorus costatus zweifeli~ Duellman _Cnemidophorus sacki zweifeli_ Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 10:589, May 2, 1960.--Capirio, Michoacán, México. Apatzingán (107); Buenavista (3); Capirio (31); Charapendo (12); Chinapa (2); 19 km. S of Corralito (3); Jazmin (2); between La Playa and Volcán Jorullo (2); Limoncito (3); 14 km. S of Lombardia (11); Nueva Italia (15); Río Marquez, 10 km. S of Lombardia (2); Río Marquez, 13 km. SE of Nueva Italia; Tafetan (18); 14 km. E of Tepalcatepec (2); Tzitzio (11); 19 km. S of Tzitzio; Volcán Jorullo (5); Ziracuaretiro; Zirimícuaro. These lizards were referred to _Cnemidophorus sacki copei_ by Duellman (1954b:12 and 1955:6); Duellman (1960a) described the subspecies _zweifeli_ and assigned it to _Cnemidophorus sacki_. Zweifel (1961:98) used the specific name C. _costatus_ for the whiptails on the southwestern part of the Mexican Plateau (_C. c. occidentalis_). Since _occidentalis_ and _zweifeli_ are conspecific, the combination _C. costatus zweifeli_ is used here for the population inhabiting the Tepalcatepec Valley. This lizard is abundant in the Tepalcatepec Valley, where it lives in open and dense scrub forest, usually at elevations of less than 1000 meters. Throughout the valley it is found in association with _Cnemidophorus deppei infernalis_, and in the lower parts of the valley it also is associated with _Cnemidophorus calidipes_. Observations made in the dry season indicate that large adults are not active at that time. On the coastal lowlands and in the valleys in the Sierra de Coalcomán _Cnemidophorus costatus zweifeli_ is replaced by _C. communis communis_. To the east in the Balsas Basin _C. costatus zweifeli_ intergrades with _C. costatus costatus_. ~Cnemidophorus deppei deppei~ Wiegmann _Cnemidophorus deppei_ Wiegmann, Herpetologia Mexicana, p. 29, 1834.--México. Type locality restricted to Tehuantepec, Oaxaca, México, by Smith and Taylor (1950b:179). _Cnemidophorus deppei deppei_, Cope, Trans. Amer. Philos. Soc., 17:31, 1892. Salitre de Estopila; San Pedro Naranjestila. This small species, which is extremely abundant on the coastal lowlands of Guerrero, seems to be rare on the coast of Michoacán, where it has been taken at elevations of 130 and 500 meters in open situations in otherwise forested areas. Duellman and Wellman (1960:25) discussed these specimens in relation to their subspecific assignment. They were referred to _Cnemidophorus deppei lineatissimus_ by Peters (1954:18). ~Cnemidophorus deppei infernalis~ Duellman and Wellman _Cnemidophorus deppei infernalis_ Duellman and Wellman, Misc. Publ. Mus. Zool. Univ. Michigan, 111:32, February 10, 1960.--Mexcala, Guerrero, México. Acahuato; Apatzingán (227); Capirio (3); El Sabino; Jazmin; La Playa (6); Lombardia (6); Nueva Italia (4); Río Marquez, 10 km. S of Lombardia (6); Río Marquez, 13 km. SE of Nueva Italia (10); south of Tancítaro; Volcán Jorullo (3). This is one of the most abundant and widespread lizards in the Tepalcatepec Valley. Throughout its range it is ecologically associated with _Cnemidophorus costatus zweifeli_, which ranges to elevations somewhat higher than the 1050 meters known for _C. deppei infernalis_. This small lizard reaches its greatest abundance in grassy areas on the floor of the Tepalcatepec Valley, where in the _Cercidium-Prosopis-Apoplanesia_ associations it occurs with _Cnemidophorus calidipes_. Duellman and Wellman (1960) discussed the variation and relationships of _Cnemidophorus deppei_, of which the subspecies _infernalis_ is restricted to the Balsas-Tepalcatepec Basin. ~Cnemidophorus lineatissimus exoristus~ Duellman and Wellman _Cnemidophorus lineatissimus exoristus_ Duellman and Wellman, Misc. Publ. Mus. Zool. Univ. Michigan, 111:44, February 10, 1960.--Rancho Santa Ana, four kilometers northeast of San Salvador, Michoacán, México. Thirteen to 25 km. S of Arteaga (18); Capirio (19); Limoncito (13); Santa Ana (22). As in _Cnemidophorus calidipes_, the distribution of this subspecies seems to be restricted to the Tepalcatepec Valley, except in the vicinity of Arteaga, where it occurs on the southern slope of the Sierra de Coalcomán. As pointed out by Duellman and Wellman (1960:46), the specimens from south of Arteaga are like those from the Tepalcatepec Valley in scutellation and coloration, and not like _Cnemidophorus lineatissimus lividus_ from the geographically closer coastal lowlands. In the Tepalcatepec Valley _Cnemidophorus lineatissimus exoristus_ inhabits gallery forests along the larger streams; in this habitat it is associated with _Ameiva undulata sinistra_. From the other species of _Cnemidophorus_ in Michoacán, _C. lineatissimus exoristus_ can be distinguished by the possession of seven longitudinal stripes in adults and by the characters of scutellation given in Table 5. ~Cnemidophorus lineatissimus lineatissimus~ Cope _Cnemidophorus lineatissimus_ Cope, Proc. Amer. Philos. Soc., 17:94, 1877.--Colima and Guadalajara. Type locality restricted to Colima, Colima, México, by Smith and Taylor (1950b:179). _Cnemidophorus lineatissimus lineatissimus_, Duellman and Wellman, Misc. Publ. Mus. Zool. Univ. Michigan, 111:41, February 10, 1960. Boca de Apiza (4). These specimens have 117 to 126 dorsal granules at midbody, a noticeably lower count than that for _Cnemidophorus lineatissimus lividus_ on the coast of Michoacán, which has 126 to 164 (148). Apparently these specimens represent immature _C. lineatissimus lineatissimus_; the differences between these and _C. lineatissimus lividus_ from nearby localities indicate that possibly the populations are distinct species and not subspecies, as suggested by Duellman and Wellman (1960:41). ~Cnemidophorus lineatissimus lividus~ Duellman and Wellman _Cnemidophorus lineatissimus lividus_ Duellman and Wellman, Misc. Publ. Mus. Zool. Univ. Michigan, 111:50, February 10, 1960.--Maruata, Michoacán, México. Barranca de Bejuco (4); Boca de Apiza (2); Coahuayana (6); El Ticuiz (7); La Placita (11); Maruata (7); Motín del Oro; Ostula (5); Playa Azul (4); Playa Cuilala (2); Pómaro (2); Salitre de Estopila (2); San Pedro Naranjestila. This is the most abundant and widespread species of _Cnemidophorus_ on the coastal lowlands of Michoacán, where it ranges from sea level to elevations of about 500 meters. In this area it inhabits dense arid scrub forest and semi-deciduous broad-leafed forest. Both of these habitats are continuous, or nearly so, along the lowlands and foothills of the Sierra de Coalcomán. This in itself may explain the abundance of _Cnemidophorus lineatissimus_ and the relative scarcity of _C. deppei_ and _C. communis_ in the coastal area, for _C. deppei_ and _C. communis_ usually inhabit more open arid scrub forest, as occurs in the Tepalcatepec Valley. Living in the dense scrub forest with _C. lineatissimus_ is _Ameiva undulata sinistra_. ~Cnemidophorus scalaris~ Cope _Cnemidophorus gularis scalaris_ Cope, Trans. Amer. Philos. Soc., 17:47, 1892.--Chihuahua, Chihuahua, México. _Cnemidophorus scalaris_, Zweifel, Bull. American Mus. Nat. Hist., 117:72, 1959. Araro (2); Jacona; Lago de Cuitzeo (42); Morelia; 21 km. N of Morelia (4). Zweifel (1959a:72) assigned the small species of _Cnemidophorus_ having a relatively low number of dorsal granules and inhabiting the southern part of the Mexican Plateau to _C. scalaris_, which he diagnosed as rarely exceeding 100 mm. in snout-vent length and always having an average of less than 100 dorsal granules at midbody and usually less than 90. Forty-two specimens from the south shore of Lago de Cuitzeo (UMMZ 119558) have 80-91 (85.8) dorsal granules. Four specimens from 21 kilometers north of Norelia (UIMNH 6952 and UMMZ 104743) have 89, 78, 92, and 84 granules; one from Morelia (UMMZ 104742) has 78; two from Araro (UMMZ 119522) have 80 and 87; one from Jacona (UIMNH 24703) has 88. Since no large adult males are present in the series from Michoacán, an adequate comparison of coloration between these and populations on the northern part of the Mexican Plateau cannot be made. _Cnemidophorus scalaris_ is a name applied to the lizards inhabiting the Mexican Plateau from Chihuahua south to Puebla by Zweifel (1959a:72). It is doubtful if all of the populations assigned to this subspecies belong there; possibly more than one species is involved, but the paucity of material prevents further analysis at this time. ~Heloderma horridum horridum~ (Wiegmann) _Trachyderma horridum_ Wiegmann, Isis von Oken, 22:421, 1829.--México. Type locality restricted to Huajintlán, Guerrero, México, by Smith and Taylor (1950b:193). _Heloderma horridum horridum_, Bogert and Martín del Campo, Bull. Amer. Mus. Nat. Hist., 109:20, April 16, 1956. Apatzingán; Coalcomán; La Placita; Oropeo; Parácuaro. This species is known from elevations of less than 1000 meters in the Tepalcatepec Valley, the Sierra de Coalcomán, and the coastal lowlands. Specimens from Coalcomán, La Placita, and Parácuaro came from areas of dense woods; those from Apatzingán and Oropeo might have come from patches of dense woods in the otherwise open scrub forest of the Tepalcatepec Valley. ~Gerrhonotus imbricatus imbricatus~ Wiegmann _Gerrhonotus imbricatus_ Wiegmann, Isis von Oken, 21:379, 1828.--México. Type locality restricted to México, Distrito Federal, by Smith and Taylor (1950b:201). _Gerrhonotus imbricatus imbricatus_, Dunn, Proc. Acad. Nat. Sci. Philadelphia, 88:475, October 20, 1936. Acuaro de las Lleguas (9); Cerro Barolosa (4); Cerro Tancítaro (36); Dos Aguas (22); Paracho; Sierra Patamba; Tinguidín; Zacapu. Specimens from the Sierra de Coalcomán are noticeably different from those inhabiting the mountains rising from the Mexican Plateau. Of 45 specimens from Cerro Tancítaro and adjacent areas on the Mexican Plateau and in the Cordillera Volcánica, 15 have twelve longitudinal rows of dorsal scales and 30 have fourteen rows. Of seven specimens from the state of México, 5 have twelve rows and 2 have fourteen; of nine specimens from central Veracruz, 8 have twelve rows and one has fourteen; of six specimens from Hidalgo, 5 have twelve rows and one has sixteen; of two specimens from Guanajuata, one has fourteen and the other has sixteen rows. All of the 35 specimens from the Sierra de Coalcomán have sixteen rows. Furthermore, these specimens have the superciliary row extended anteriorly, so that the anterior superciliary is in broad contact with the loreal. Specimens from Cerro Tancítaro have a shorter superciliary row, so that the anterior superciliary is not in broad contact with the loreal. These characters were used by Tihen (1949:220) to distinguish _Gerrhonotus imbricatus ciliaris_ from _G. imbricatus imbricatus_. According to Tihen, the subspecies _G. imbricatus ciliaris_ ranges from Guanajuato and Hidalgo northward to Chihuahua and Coahuila, whereas the nominal subspecies occurs from Michoacán and Hidalgo southward to Oaxaca. Specimens from the Sierra de Autlán in Jalisco are like those from Cerro Tancítaro; consequently, there seems to be no connection between the populations of _G. imbricatus ciliaris_ in the mountains of the northern part of the Mexican Plateau with the _ciliaris_-like individuals found in the Sierra de Coalcomán. The acquisition and study of additional material from throughout the range of the species is necessary to clarify the picture of geographic variation. Until then, I prefer to consider all of the specimens from Michoacán as _Gerrhonotus imbricatus imbricatus_. The largest specimen is a male having a snout-vent length of 136 mm. Two juveniles collected in July 24, 1960, have snout-vent lengths of 36 and 42 mm. A specimen having a snout-vent length of 127 mm. and a tail length of 145 mm. was regurgitated by a _Crotalus pusillus_, which had a body length of 550 mm. _Gerrhonotus imbricatus imbricatus_ is an inhabitant of coniferous forests. In the Cordillera Volcánica it occurs from 1500 to 3500 meters at the top of Cerro Tancítaro. In the Sierra de Coalcomán it occurs from 2100 to 2700 meters. On July 4, 1955, a pair was found in copulation beneath a pine log at 2700 meters on Cerro Barolosa. The male was lying on top of the female and was holding her head firmly in his jaws; the male's tail was curled under the female's tail, so that the cloacae were in contact. Serpentes ~Typhlops braminus~ (Daudin) _Eryx braminus_ Daudin, Hist.... des reptiles, 7:279, 1803.--Vazagapatam, India. _Typhlops braminus_, Cuvier, Règne animal, ed. 2, 2:73, 1829. Apatzingán; Arteaga. Both specimens known from Michoacán were collected by Gadow in 1908. Peters (1954:20) remarked that the specimen from Arteaga probably does not indicate a rapid spreading of the species, which most likely was introduced into México at the time that vessels were stopping at Acapulco from the Philippines (Taylor, 1940b:444), but instead may indicate that pack trains from Acapulco passed through the Sierra de Coalcomán. The occurrence of this snake along a long-used _camino_ substantiates this belief. ~Leptotyphlops bressoni~ Taylor _Leptotyphlops bressoni_ Taylor, Copeia, No. 1:5, March 9, 1939.--Hacienda El Sabino, Michoacán, México. El Sabino. This species still is known definitely only from the type specimen collected on the lower slopes of the Cordillera Volcánica at the northern edge of the Tepalcatepec Valley. A specimen (now lost) reported from Aguililla by Cope (1887:63) possibly represents this species (see Smith and Taylor, 1945:21, and Peters, 1954:20). ~Leptotyphlops gadowi~ Duellman _Leptotyphlops gadowi_ Duellman, Copeia, No. 2:93, May 29, 1956.--Apatzingán, Michoacán, México. Apatzingán. No additional specimens of this species have been collected since the species was described by Duellman (1956b:93). Data given with the specimen by Gadow indicate that it came from his camp above Apatzingán at an elevation of about 800 meters. Although the exact position of this camp is unknown, the lower slopes of the Cordillera Volcánica above Apatzingán usually support arid scrub forest at elevations below 1000 meters. Therefore, this species probably is an inhabitant of the arid scrub forest. ~Leptotyphlops phenops bakewelli~ Oliver _Leptotyphlops bakewelli_ Oliver, Occ. Pap. Mus. Zool. Univ. Michigan, 360:16, November 20, 1937.--Paso del Río, Colima, México. _Leptotyphlops phenops bakewelli_, Smith, Proc. U. S. Natl. Mus., 93:445, October 29, 1943. La Placita (4); La Salada; Ostula. The five specimens from the coastal lowlands are from elevations of less than 150 meters; these were collected by Peters (1954:20); the specimen from La Salada is from an elevation of 580 meters in the Tepalcatepec Valley. Peters (_loc. cit._) remarked that the rostral and the tip of the tail that were described as white by Oliver (1937:17) actually are sulphur-yellow in life. ~Loxocemus bicolor~ Cope _Loxocemus bicolor_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 13:77, June 30, 1861.--La Unión, El Salvador. _Loxocemus sumichrasti_ Bocourt, Ann. Sci. Nat., ser. 6, 4:1, 1876.--Tehuantepec, Oaxaca, México. Apatzingán (6); La Orilla; Lombardia. As noted by Peters (1954:21), this species was not recorded from Michoacán by Smith and Taylor (1945:27), but Gadow (1930:30) collected a specimen at La Orilla in 1908. This specimen (BMNH 1914.1.28.124) is a male having 235 ventrals and 47 caudals, a dark brown dorsum, and cream-colored labials and venter. The anterior chin-shields are considerably longer than the scales bordering the chin-shields. In these characters this specimen agrees with the diagnosis of _Loxocemus bicolor_ given by Taylor (1940c:447), who revived _Loxocemus sumichrasti_ Bocourt. Of the six specimens from Apatzingán in the Tepalcatepec Valley, three males have 243 to 253 (246.6) ventrals and 44 to 45 (44.3) caudals; three females have 238 to 247 (244.0) ventrals and 42 to 44 (43.0) caudals. Certain characters of scutellation utilized by Taylor for separating _L. bicolor_ and _L. sumichrasti_ are inconsistent in this series. The chin-shields are longer than the adjacent scales, like those illustrated in _L. bicolor_ by Taylor (_op. cit._, fig. 1). The relative lengths of the prefrontal and internasal sutures are subequal, or the prefrontal suture is slightly longer. Thus, in these characters of scutellation these snakes are like _L. bicolor_, but in coloration they are like _L. sumichrasti_; the dorsal color in life was an iridescent dark bluish gray, and the belly was pale gray or bluish gray. The supposed differences in scutellation between _L. bicolor_ and _L. sumichrasti_ have been questioned by Woodbury and Woodbury (1944:360); these authors treated _L. sumichrasti_ as a subspecies of _L. bicolor_. As pointed out by Zweifel (1959b:5), such an arrangement is not tenable, for, although individuals with each kind of color pattern have not been collected together at any one locality, the over-all geographic picture is one of sympatric distribution. Only snakes having the coloration of _L. sumichrasti_ have been collected in the Balsas-Tepalcatepec Basin. I agree with Zweifel (_loc. cit._) that on the basis of morphological similarities and sympatric distribution, _L. bicolor_ and _L. sumichrasti_ seem to be dimorphic phases of the same species, showing no more striking differences in coloration than _Lampropeltis getulus californiae_, a now classical example of pattern dimorphism in snakes. In Michoacán, as in other parts of its range, _Loxocemus bicolor_ inhabits arid scrub forest environments at low elevations. ~Boa constrictor imperator~ Daudin _Boa imperator_ Daudin, Hist. nat.... des reptiles, 5:150, 1803.--México. Type locality restricted to Córdoba, Veracruz, México, by Smith and Taylor (1950a:347). _Boa constrictor imperator_, Forcart, Herpetologica, 7:199, December 31, 1951. Apatzingán (4); Coalcomán; El Sabino (2); La Placita; La Playa (2); Lombardia; Nueva Italia (2); Río Cachán; Río Marquez, 13 km. SE of Nueva Italia; Río Nexpa; Volcán Jorullo. These specimens have come from a variety of habitats from elevations of less than 1,000 meters. The species seems to be equally abundant in the broad-leafed semi-deciduous forests of the coastal foothills and in the arid Tepalcatepec Valley. In the latter area most of the specimens were collected at night. ~Coniophanes fissidens dispersus~ Smith _Coniophanes fissidens dispersus_ Smith, Proc. U. S. Natl. Mus., 91:106, November 13, 1941.--El Limoncito, Guerrero, México. Arteaga. Further collecting in southern Michoacán has failed to add additional material of this species, which is known in the state from the one specimen collected by Gadow in 1908. The species possibly ranges throughout the coastal foothills of the Sierra de Coalcomán. Peters (1954:21) described the specimen from Arteaga. ~Coniophanes lateritius lateritius~ Cope _Coniophanes lateritius_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 13:524, March 31, 1862.--Guadalajara, Jalisco, México. _Coniophanes lateritius lateritius_, Smith and Grant, Herpetologica, 14:20, April 25, 1958. Nineteen km. S of Arteaga. The one specimen available from Michoacán of this apparently rare species was discussed by Wellman (1959:127), who pointed out that although the specimen was geographically intermediate between the subspecies _C. l. lateritius_ (Jalisco and Nayarit) and _C. l. melanocephalus_ (Morelos and Puebla), the specimen (UMMZ 118954) was like _C. l. lateritius_ in scutellation and in color pattern differed from other known specimens of the species in having had in life a pale orange, instead of a brick-red, dorsum. Additional specimens from the Sierra de Coalcomán will be required in order to determine whether this specimen is a representative of an orange-colored population or merely is aberrant in coloration. The present specimen is from an elevation of 900 meters in oak forest on the southern slopes of the Sierra de Coalcomán; other locality records for the species indicate that it inhabits broad-leafed forest in foothills from Nayarit to Puebla. ~Conophis vittatus vittatus~ Peters _Conophis vittatus_ Peters, Monats. Akad. Wiss. Berlin, p. 519, 1860.--No type locality given. Type locality restricted to Laguna Coyuca, Guerrero, México, by Smith and Taylor (1950a:331). _Conophis vittatus vittatus_, Smith, Jour. Washington Acad. Sci., 31:119, March 17, 1941. Arteaga; Coalcomán (4); La Playa; 19 km. S of Tzitzio. All specimens of this terrestrial snake have been collected in areas of scrub forest between 800 and 1100 meters above sea level. Since the species is known from the coastal regions of Guerrero and Colima, its absence from the cost of Michoacán is unexplainable; probably the lack of specimens from these areas is due solely to inadequate collecting. ~Conopsis biserialis~ Taylor and Smith _Conopsis biserialis_ Taylor and Smith, Univ. Kansas Sci. Bull., 28 (2):333, November 12, 1942.--Ten miles west of Villa Victoria, México, México. Capácuaro (5); Cerro San Andrés; Cherán; Ciudad Hidalgo; Macho de Agua (4): Pátzcuaro (8); Tancítaro (24); Uruapan (9); 24 km. SE of Zitácuaro (14). This species is abundant in the coniferous forests at elevations from 1550 to 2800 meters throughout the Cordillera Volcánica; apparently it does not occur in the Sierra de Coalcomán. On August 1, 1956, a copulating pair was found beneath a rock at Capácuaro. One of the best characters to distinguish this species from _Toluca lineata_, which occurs with _Conopsis_ throughout its range in Michoacán, is the presence of large, black ventral blotches in _Conopsis biserialis_, as contrasted with the two rows of small black spots in _Toluca lineata_. ~Conopsis nasus~ Günther _Conopsis nasus_ Günther, Catalogue... snakes... British Museum, p. 6, 1858.--California (in error). Type locality restricted to Guanajuato, Guanajuato, México, by Smith and Taylor (1950a:330). Carapan (2); Erongaricuaro; Maravatio (3); Morelia (2); Nahuatzen; Pátzcuaro (7); Tacícuaro (8); Tancítaro. This species has been collected in oak, pine-oak, and fir forests at elevations of 1900 to 2450 meters on the mountains rising from the Mexican Plateau. It does not seem to be so abundant as _Conopsis biserialis_. Sufficient ecological data to determine differences in habitat between the two species have not been compiled. ~Diadophis dugesi~ Villada _Diadophis punctatus dougesii_ Villada, La Naturaleza, 3:226, 1875.--Potreros de Balbuena, Distrito Federal, México. _Diadophis dugesii_, Blanchard, Bull. Chicago Acad. Sci., 7:51, December 30, 1942. Morelia (2); Pátzcuaro; Quiroga. Apparently this snake is uncommon in Michoacán. It has been found only at elevations of 1900 to 2200 meters in pine and pine-oak forests on the mountains rising from the Mexican Plateau. ~Dryadophis melanolomus stuarti~ Smith _Dryadophis melanolomus stuarti_ Smith, Proc. U. S. Natl. Mus., 93:418, October 29, 1943.--Acapulco, Guerrero, México. Coahuayana; El Ticuiz; La Placita (3); Punto San Juan de Lima; Punto San Telmo. The few specimens indicate that in Michoacán, as elsewhere on the Pacific coast of México, this species is restricted to forested regions on the coastal plain. It does not occur in the Tepalcatepec Valley. The coloration, in life, of a juvenile (UMMZ 114604) is as follows: The dorsum is uniform pale grayish tan on posterior one-third of body and on tail; anteriorly there are pale grayish tan middorsal blotches separated by grayish white interspaces, which are about one-half the length of the blotches. Posteriorly the blotches are less distinct, fading into the uniform grayish tan ground color of the posterior part of the body. The blotches extend laterally onto the fourth and fifth scale rows. Large squarish lateral intercalary blotches of darker brown interconnect with the dorsal blotches. The top of the head is pale olive-brown; a dark brown postorbital stripe extends from the eye to the posterior edge of the last upper labial. The labials, chin, and ventrals 1-30 are creamy white, changing to a dusty cream-color posteriorly; the chin and ventrals 1-30 are heavily spotted with dark brown. The iris is a cream-color above and chocolate brown below; the tongue is blue. ~Drymarchon corais rubidus~ Smith _Drymarchon corais rubidus_ Smith, Jour. Washington Acad. Sci., 31:474, November 11, 1941.--Rosario, Sinaloa, México. Apatzingán (5); Arroyo El Salto; Arteaga; Capirio; El Sabino (7); La Palma; La Placita; Ostula; San Juan de Lima. Not all of the specimens from Michoacán are typical in color pattern of this subspecies, as defined by Smith (1941a:475). All specimens from the Tepalcatepec Valley are uniformly black above; they have reddish or cream-colored chins and the anterior two-thirds of the belly salmon-pink or reddish buff. Individuals from the Sierra de Coalcomán (Arteaga and Arroyo El Salto) are like those from the Tepalcatepec Valley. Three specimens from the coastal lowlands differ noticeably in color pattern: UMMZ 104504, adult male (Ostula).--Pale brown above flecked with black anteriorly; at midbody, flecks form narrow transverse bands that become progressively wider posteriorly, until on tail no brown pigment evident, all ventrals reddish buff, except last eight, which are black. UMMZ 104602, adult female (La Placita).--Black above, reddish cross-bands and flecks on all of body; dorsal and ventral surfaces of tail black; chin cream-color and entire belly reddish buff. UMMZ 114626, adult male (San Juan de Lima).--Black above; dull rust-colored cross-bands on anterior half of body; chin white; belly rust-colored on anterior two-thirds of body and black posteriorly. One specimen from La Palma on the Mexican Plateau (KU 29275) has the top of the head an olive-color, the entire dorsum black, the chin and ventrals 1-42 a cream-color, remainder of venter black, and all of the labials heavily barred with black. A juvenile from Capirio in the Tepalcatepec Valley (UMMZ 114627) is black above and has pale olive-colored flecks on the anterior one-third of the body; the top of the head is dark olive-brown, and the sides of the head are somewhat paler. Anteriorly the belly is a cream-color; posteriorly it is black. The specimens from the Tepalcatepec Valley are typical of _Drymarchon corais rubidus_. Those from the coastal lowlands differ in having large areas of brown or red pigment on the dorsum, a condition not mentioned by Smith in his description of the subspecies. The specimen from La Palma, like many others from various localities on the Mexican Plateau, resembles in certain characters _D. corais orizabensis_ (Smith, _op. cit._: 477). Our knowledge of the geographical variation in coloration in this species is incomplete; many populations have been assigned to subspecific rank without justification. In Michoacán this species is found from sea level to 1350 meters in the Sierra de Coalcomán and to 1300 meters at La Palma on Lago de Chapala. It has been collected in scrub forest, semi-deciduous broad-leafed forest, and oak forest. ~Drymobius margaritiferus fistulosus~ Smith _Drymobius margaritiferus fistulosus_ Smith, Proc. U. S. Natl. Mus., 92:383, November 5, 1942.--Miramar, Nayarit, México. Apatzingán (3); Coahuayana; Coalcomán (3); El Sabino (3); El Ticuiz; 12 km. S of Tzitzio. This snake is abundant in the lowlands of the state; the few specimens listed above are indicative not of the rarity, but rather of the speed and agility, of this diurnal snake. It most frequently is found near water, where there is a dense growth of vegetation. One individual was observed in a large pool inhabited by several small _Rana pipiens_, and another was seen along the bank of a hyacinth-choked river channel. A third individual was captured while it was in pursuit of a _Cnemidophorus_. This species has been collected on the coastal lowlands and seaward foothills of the Sierra de Coalcomán and in the Tepalcatepec Valley to elevations of 1150 meters. ~Elaphe triaspis intermedia~ (Boettger) _Pityophis intermedius_ Boettger, Ber. Offen. Vereins. Naturk., 22:148, 1883.--México. Type locality restricted to Hacienda El Sabino, Michoacán, México, by Dowling (1960:74). _Elaphe triaspis intermedia_, Mertens and Dowling, Senckenbergiana, 33:201, November 15, 1952. Twenty-four km. E of Apatzingán; Chupio; El Sabino (4); 11 km. E of Emiliano Zapata. Dowling (1960) has shown that specimens from the Balsas-Tepalcatepec Basin have fewer ventrals and caudals than those from the Sierra del Sur or the coast. All specimens from Michoacán were collected in open forest, either scrub or oak forest. They were found in drier situations than those described for the species in southern Tamaulipas by Martin (1958:69). In Michoacán _Elaphe triaspis intermedia_ is known from the Tepalcatepec Valley, the lower slopes of the Cordillera Volcánica, and the western edge of the Mexican Plateau at an elevation of 1350 meters. It probably occurs in the lower parts of the Sierra de Coalcomán and along the Pacific coast, for it is known from the coastal lowlands of Guerrero and Colima. In August, 1951, I saw a snake that probably was this species in Barranca de Bejuco. ~Enulius unicolor~ (Fischer) _Geophis unicolor_ Fischer, Abh. Nat. Ver. Bremen, 7:227, 1882.--México. Type locality restricted to Chilpancingo, Guerrero, México, by Smith and Taylor (1950a:331). _Enulius unicolor_, Taylor and Smith, Univ. Kansas Sci. Bull., 25:247, July 10, 1939. Between Ario de Rosales and La Playa; Coalcomán; Jungapeo (4); between Zitácuaro and Tuxpan. This small snake has been collected from beneath rocks in brushy areas and broad-leafed forest between 900 and 1800 meters; it has not been found in coniferous forest. The limited ecological data suggest that the species inhabits the transition zone between the tropical scrub forest and the temperate hardwood forest. All of the specimens have 17 rows of scales; four males have 169-178 (174.2) ventrals and 102-111 (106.8) caudals; two females have 192 and 195 ventrals and 96 and 87 caudals. Three individuals have one postocular on one side and two on the other; in the other specimens there are two postoculars on each side. The largest male has a body length of 232 mm. and a tail length of 130 mm.; the largest female has a body length of 274 mm. and a tail length of 119 mm. ~Geagras redimitus~ Cope _Geagras redimitus_ Cope, Jour. Acad. Nat. Sci. Philadelphia, ser. 2, 8:141, 1876. San Juan de Lima (2). Previously this species was known definitely only from the Plains of Tehuantepec, Oaxaca. _Sphenocalamus lineolatus_ was described by Fischer (1883:5) from Mazatlán; this name has been placed in the synonymy of _Geagras redimitus_ Cope. Although Fischer gave the type locality only as "Mazatlán" and did not designate the state, it is probable that the type originated from Mazatlán, Sinaloa. The present specimens are from a locality almost midway between Tehuantepec and Mazatlán and support the possibility that _Geagras_ ranges along the Pacific coast of México from Oaxaca to Sinaloa. The two specimens from Michoacán (UMMZ 114446-7), both males, have 118 and 122 ventrals, 31 and 33 caudals, body lengths of 108 and 81 mm., and tail lengths of 20 and 15 mm. Both have 1-1 preoculars, 1-1 postoculars, 1-2 temporals, 6-6 upper labials, and 5-5 lower labials. In life, the dorsum was pale tan; the top of the head and the middorsal and lateral stripes were dark brown; the belly was white. The occipital spots were pale pinkish tan. Both specimens were found beneath rocks in tropical semi-deciduous forest at an elevation of 15 meters on the coastal plain. ~Geophis dugesi~ Bocourt _Geophis dugesii_ Bocourt, Miss. Scientifique au Mexique et dans l'Amerique Centrale, Rept., livr. 9:573, 1883.--Tangancícuaro, Michoacán, México. Carapan; Tangancícuaro; Zacapu. Aside from the three specimens listed above, there are two (SU 4407-8) bearing the data "Michoacán." Bocourt (1883:574) stated that the type specimen from Tangancícuaro had six or seven pale cross-bands on the anterior part of the body. An illustration, presumably of the same specimen, by Dugès (1884:Pl. 9) shows five distinct and one indistinct cross-bands. Of the four specimens that I have examined, none has more than three pale cross-bands, and one has only one indistinct cross-band. Two females have 154 and 158 ventrals and 38 and 37 caudals; two males have 150 and 151 ventrals and 43 and 42 caudals. This species is known only from elevations between 1750 and 2050 meters on the southwestern edge of the Mexican Plateau in the state of Michoacán. ~Geophis incomptus~ Duellman _Geophis incomptus_ Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 605:3, May 29, 1959.--Dos Aguas, Michoacán, México. Dos Aguas (15). This species, which seems to be related to _Geophis maculiferus_, is known only from the pine-oak forest in the vicinity of Dos Aguas (elevation 2100 meters) in the Sierra de Coalcomán. Aside from the five specimens comprising the type series, there are ten other specimens in the Museum of Zoology at the University of Michigan collected by Floyd L. Downs in July, 1960. Data from these specimens and those comprising the type series show that in this sample seven males have 146-153 (149.3) ventrals and 35-37 (36.0) caudals; eight females have 150-154 (152.4) ventrals and 29-34 (32.5) caudals. The largest specimen is a female with a body length of 344 mm. and a tail length of 53 mm. ~Geophis maculiferus~ Taylor _Geophis maculiferus_ Taylor, Univ. Kansas Sci. Bull., 27:119, December 30, 1941.--Near Cicio [_sic_] = Tzitzio, Michoacán, México. Tzitzio. The type and only known specimen of _Geophis maculiferus_ (UIMNH 25078) is a female having 140 ventrals and 30 caudals, dorsal scales in 15 rows, one postocular, and an anterior temporal. Only one other species in México has dorsal scales in 15 rows and has an anterior temporal; that species is _G. incomptus_, which differs from _G. maculiferus_ in having six or seven lower labials, instead of five, and in having the edges of the ventrals dark, instead of a uniformly cream-colored belly. The locality from which the specimen was obtained lies at an elevation of 1630 meters on the southern slope of the Cordillera Volcánica. At that elevation there is an interdigitation of arid tropical scrub forest and pine-oak forest; probably _Geophis maculiferus_ inhabits the pine-oak forest. ~Geophis nigrocinctus~ Duellman _Geophis nigrocinctus_ Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 605:1, May 29, 1959.--Dos Aguas, Michoacán, México. Dos Aguas (3). The three specimens comprising the type series of the species were found beneath logs and in a stump in pine-oak forest at an elevation of 2100 meters. A discussion of the variation in these specimens and of probable relationships of the species was given by Duellman (1959). Floyd Downs spent several days at Dos Aguas in July, 1960; although he found ten specimens of _Geophis incomptus_, no further specimens of _G. nigrocinctus_ were obtained. ~Geophis petersi~ Boulenger _Geophis petersii_ Boulenger, Catalogue Snakes... British Museum, 2:321, September 23, 1894.--Mexico City. Type locality restricted to Pátzcuaro, Michoacán, México, by Smith and Taylor (1950a:335). Cherán; Coalcomán; Morelia; Pátzcuaro (6). This seems to be the most widespread species of _Geophis_ in Michoacán. It has been found at elevations between 950 and 2350 meters, chiefly in pine or pine-oak forest. Boulenger (1894:321) described _Geophis petersi_ from a specimen stated to be from Mexico City, a locality which probably is in error. The only localities from which the species is definitely known are those listed in this account. Three males and five females from the Mexican Plateau and the Cordillera Volcánica have respectively 140-144 (141.7) and 143-151 (146.0) ventrals and 39-41 (40.0) and 29-35 (33.2) caudals. All have dorsal scales in 15 rows, 1 postocular, no anterior temporal, and a relatively small triangular supraocular. The specimen from Coalcomán (UMMZ 104698) was referred to _Geophis nasalis_ by Peters (1954:22). This specimen is abnormal in several characters; in five places there is a fusion and separation of the vertebral and paravertebral scale rows, producing a change from 17 to 15 rows of dorsal scales. Fusion of the three rows takes place at the level of the 8th, 41st, 47th, 54th, and 65th ventrals. Furthermore, there is a small secondary postocular on each side of the head. In other characters the specimen is like _G. petersi_; the resemblances to that species are greater than to _G. nasalis_, which has been recorded from Guatemala and southern Chiapas. ~Geophis tarascae~ Hartweg _Geophis tarascae_ Hartweg, Occ. Pap. Mus. Zool. Univ. Michigan, 601:1, May 4, 1959.--Uruapan, Michoacán, México. Uruapan (3). A female of this species was collected in the Parque Nacional at the north edge of Uruapan in 1899, and a male was taken there in 1947; these specimens were used by Hartweg in his description of the species. Floyd L. Downs obtained another specimen in the Parque Nacional on July 19, 1960. It has 164 ventrals and 46 caudals; in life, the ground color of the neck was brown with a purplish tint; the dorsal markings were black; the chin was a cream-color, and the belly was white. This specimen is distinguished from those of all other species of _Geophis_ in Michoacán in that it has dark irregular cross-bars on the dorsum and a row of dark spots on the venter. ~Hypsiglena torquata ochrorhyncha~ Cope _Hypsiglena ochrorhyncha_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 12:246, November 15, 1860.--Cape San Lucas, Baja California, México. _Hypsiglena torquata ochrorhyncha_, Bogert and Oliver, Bull. Amer. Mus. Nat. Hist., 83:378, March 30, 1945. Tupátaro. The systematic status of the geographic variants of _Hypsiglena_ in México and southwestern United States has been commented on by several authors. Tanner (1944) considered _H. torquata_ and _H. ochrorhyncha_ to be distinct species; Bogert and Oliver (1945:379) and Duellman (1957b:238) presented evidence indicating that _H. torquata_ and _H. ochrorhyncha_ intergrade in Sinaloa and southern Sonora. In _Hypsiglena_ the scutellation, including the numbers of labials, dorsals, ventrals, and caudals, seem to vary in a clinal manner. Nevertheless, these snakes can be divided into two distinct populations on the basis of the nuchal color pattern, consisting of an _ochrorhyncha_-type (a broad dark nape-band, the lateral edges of which extend anteriorly and fuse with a postorbital stripe, and a narrow nape stripe extending from the posteromedian edges of the parietals to the dark nape band) and a _torquata_-type (a somewhat narrower dark nape-band bordered anteriorly by a pale nuchal area, and no dark nape stripe). Snakes having the _ochrorhyncha_-type of nuchal pattern are found on the Mexican Plateau from Michoacán northward into the desert regions of Sonora and the southwestern United States. Snakes having the _torquata_-type of pattern are found on the coastal lowlands and adjacent slopes of the Sierra Madre Occidental from southern Sinaloa to Colima and thence inland in the Balsas-Tepalcatepec Basin to Morelos and Guerrero. An exception is _Hypsiglena torquata dunklei_ from Forlón and San Fernando, Tamaulipas; it has the _torquata_-type of nuchal pattern. The distributional picture is somewhat complicated because some individuals having the _torquata_-type of nuchal pattern also have a faint nape stripe. If these are taken as exceptions, the general picture of distribution in México is _H. t. torquata_ on the Pacific lowlands from Sinaloa southward to the Balsas Basin and _H. t. ochrorhyncha_ on the Mexican Plateau. Smith (1943:433) resurrected _Hypsiglena jani_ Dugès for the snakes of the _ochrorhyncha_-type on the southern part of the Mexican Plateau. He stated that the southern specimens differed from northern ones in having a nuchal spot 9 or 10 scales in length, as compared with a spot 2 to 6 scales in length in northern specimens. A cursory examination of specimens from the areas between Arizona and Michoacán showed that there is a gradual increase in the size of the spot from north to south. If no other characters can be found to distinguish the populations, they should be considered as a single subspecies. _Hypsiglena affinis_ differs from _H. torquata_ in possessing 19 instead of 21 rows of dorsal scales. Additional material is needed from the western slopes of Jalisco and the Barrancas in Zacatecas and Durango, before definite allocation of _affinis_ can be made. Bogert and Oliver (1945:379) discussed the status of certain named populations in Baja California and concluded that only one species occurs there, and that the species probably is conspecific with _H. torquata_. A careful review of the genus _Hypsiglena_ might show that there is only one species. The one specimen from Michoacán (USNM 46513) is from an elevation of about 2300 meters near the southern edge of the Mexican Plateau. ~Hypsiglena torquata torquata~ (Günther) _Leptodeira torquata_ Günther, Ann. Mag. Nat. Hist., ser. 3, 5:170.--Laguna Island, Nicaragua (in error). _Hypsiglena torquata torquata_, Taylor, Univ. Kansas Sci. Bull., 25:371, July 10, 1939. Apatzingán; Capirio; Cofradía. Specimens from the three mentioned localities have the dark nuchal spot bordered anteriorly by a pale blotch. In life the specimen from Capirio (UMMZ 114424) had rich reddish brown dorsal spots; the dorsal ground color was grayish white above and somewhat more gray laterally. The pale nuchal area was a cream-color, and the iris was grayish red. All of the specimens were found in the arid scrub forest in the Tepalcatepec Valley at elevations between 200 and 350 meters. ~Imantodes gemmistratus gracillimus~ (Günther) _Dipsas gracillima_ Günther, Biol. Centrali-Americana, Rept., p. 177, July, 1895.--southern México. Type locality restricted to Acapulco, Guerrero, México, by Smith and Taylor (1950a:331). _Imantodes gemmistratus gracillimus_, Zweifel, Amer. Mus. Novitates, 1961:12, September 16, 1959. La Orilla. The specimen from La Orilla was reported by Peters (1954:23) as _Imantodes gemmistratus oliveri_; Zweifel (1959c) showed that _I. g. oliveri_ did not range west of Tehuantepec and that the snakes inhabiting the coastal lowlands of Guerrero, Michoacán, and Colima were assignable to the subspecies _gracillimus_. It may be assumed that this subspecies ranges throughout the coastal lowlands and foothills of the Sierra de Coalcomán. ~Imantodes gemmistratus latistratus~ (Cope) _Dipsas gemmistrata latistrata_ Cope, Bull. U. S. Natl. Mus., 32:68, 1887.--Southern Jalisco. Type locality restricted to Guadalajara, Jalisco, México, by Smith and Taylor (1950a:334). _Imantodes gemmistratus latistratus_, Zweifel, Amer. Mus. Novitates, 1961:3, September 16, 1959. El Sabino. The one specimen from Michoacán was collected near the upper limits of the scrub forest on the slopes of the Cordillera Volcánica. Zweifel (1959c:10) stated that in certain aspects of coloration this specimen was like _I. gemmistratus gracillimus_, but in scutellation and other features of coloration it was like _I. g. latistratus_. There are too few specimens of this species to define the ranges of the various subspecies with any degree of accuracy, but from the limited number of specimens available, it seems that _I. gemmistratus gracillimus_ occurs on the Pacific lowlands from Guerrero northward to Colima. Northward on the Pacific lowlands from Colima to Sinaloa and in the Balsas-Tepalcatepec Basin is found _I. gemmistratus latistratus_. ~Lampropeltis doliata~ (Linnaeus) _Coluber doliatus_ Linnaeus, Systema naturae, ed. 12, 1:379, 1766.--Charleston, South Carolina. _Lampropeltis doliata_, Klauber, Copeia, No. 1:11, April 15, 1948. Coalcomán (3); El Sabino; 24 km. W of Morelia; Río Nexpa; Uruapan. The few specimens of this species from Michoacán show a wide range of variation; furthermore, the present systematic status of the subspecies of _Lampropeltis doliata_ portrays an incongruous pattern of distribution. Specimens from the Sierra de Coalcomán have relatively narrow red bands that are not interrupted dorsally by extensions of the black rings; the scales in the red bands have black tips. The specimen from El Sabino (EHT-HMS 5253) and the one from the Río Nexpa on the coast (USNM 31491) have broader red bands; the scales in the red bands do not have black tips. A specimen from 24 kilometers west of Morelia (UIMNH 17782) and one from Uruapan (UMMZ 121508) have the red bands interrupted dorsally by extensions from the black rings. Specimens from the Sierra de Coalcomán were referred to _L. doliata blanchardi_ by Peters (1954:24), who noted that in some characters these snakes were like _L. d. nelsoni_ and in others like _L. d. polyzona_. The individual from El Sabino was referred to _L. d. nelsoni_ by Taylor (1940c:465); the one from 24 kilometers west of Morelia was referred to _L. d. arcifera_ by Smith (1942c:198). If these assignments are correct, three subspecies of _Lampropeltis doliata_ occur in Michoacán: _blanchardi_ in the Sierra de Coalcomán, _nelsoni_ on the coast and in the Tepalcatepec Valley, and _arcifera_ on the Mexican Plateau and in the Cordillera Volcánica. Such a distribution is plausible, but the few specimens and our general lack of knowledge of the variation and relationships of the different populations do not permit a definite assignment at this time. ~Lampropeltis ruthveni~ Blanchard _Lampropeltis ruthveni_ Blanchard, Occ. Pap. Mus. Zool. Univ. Michigan, 81:8, April 28, 1920.--Pátzcuaro, Michoacán, México. Morelia; Pátzcuaro; Tacícuaro. At the present time this species is known definitely from only three localities on the Mexican Plateau in Michoacán. An incomplete skin from El Sabino (EHT-HMS 5438) was referred to this species by Taylor (1940c:465); the specimen cannot be found, so verification of the identification cannot be made at this time. ~Leptodeira latifasciata~ (Günther) _Hypsiglena latifasciata_ Günther, Biologia Centrali-Americana, Reptilia, p. 138, October, 1894.--Southern México. Type locality restricted to Huajintlán, Morelos, México, by Smith and Taylor (1950a:331). _Leptodeira latifasciata_, Dunn, Proc. Natl. Acad. Sci., 22:696, December, 1936. Apatzingán; El Sabino; La Playa; 32 km. E of Nueva Italia. This nocturnal snake apparently ranges throughout the arid Balsas-Tepalcatepec Valley to elevations of about 1050 meters. It has been collected only in the arid scrub forest. Aside from the specimens listed by Duellman (1958a:93), there is one (UMMZ 120223) having eight body blotches, a body length of 510 mm. and a tail length of 103 mm. ~Leptodeira maculata~ (Hallowell) _Megalops maculatus_ Hallowell, Proc. Acad. Nat. Sci. Philadelphia, 13:488, March 31, 1862.--"Tahiti." Type locality restricted to Manzanillo, Colima, México, by Duellman (1958a:54). _Leptodeira maculata_, Duellman, Bull. Amer. Mus. Nat. Hist., 114:53, February 24, 1958. Aguililla (2); Apatzingán (24); Arteaga (2); Capirio (3); Charapendo (2); Coahuayana (3); Cofradía; Cuatro Caminos; La Placita (3); Lombardia (69); Nueva Italia (29); Pómaro; Río Marquez, 10 km. S of Lombardia (2); Salitre de Estopila; Tafetan (2); Volcán Jorullo. This snake is abundant in the arid Tepalcatepec Valley; most of the specimens have been collected in arid scrub forest at elevations of less than 500 meters. With the onset of the rains in late June and early July, large numbers of these snakes can be found around temporary pools, where they feed on small frogs and toads. In the dry season few individuals were found, and all of those were beneath cover. Specimens from the coast have more body-blotches than do those from the Tepalcatepec Valley (Duellman, 1958a:56); otherwise the snakes show little variation. ~Leptodeira splendida bressoni~ Taylor _Leptodeira bressoni_ Taylor, Univ. Kansas Sci. Bull., 25:321, July 10, 1939.--Hacienda El Sabino, Michoacán, México. _Leptodeira splendida bressoni_, Duellman, Bull. Amer. Mus. Nat. Hist., 114:84, February 24, 1958. Coalcomán (3); El Sabino (3); Uruapan (5). The range of _Leptodeira splendida bressoni_ apparently does not overlap that of _Leptodeira maculata_; the latter is restricted to the lower reaches of the arid scrub forest, whereas _L. s. bressoni_ inhabits the upper limits of the arid scrub forest and the lower part of the pine-oak forest. Specimens have been collected between 950 and 1630 meters on the slopes of the Cordillera Volcánica and at 950 meters in the Sierra de Coalcomán. At Uruapan individuals were found beneath rocks along a stream and in a stone fence. _Leptodeira duellmani_, which was described from Coalcomán by Peters (1954:25), is an aberrant individual of _L. s. bressoni_ (Duellman, 1958a:56). ~Leptophis diplotropis~ (Günther) _Ahaetulla diplotropis_ Günther, Ann. Mag. Nat. Hist., ser. 4, 9:25, 1872.--Tehuantepec, Oaxaca, México. _Leptophis diplotropis_, Bocourt, Mission scientifique au Mexique et dans l'Amerique Centrale, Reptiles, livr. 15:835, 1897. Between Aguililla and Dos Aguas; Arteaga; Coalcomán; El Diezmo; El Sabino (5); La Playa; Ocorla. Most specimens of this species have been collected in tropical semi-deciduous forest at elevations of less than 1000 meters. In the Sierra de Coalcomán one was taken in pine-oak forest at an elevation of 1700 meters near Ocorla; another was found in broad-leafed forest between Aguililla and Dos Aguas at an elevation of 1600 meters. Most individuals have been seen in trees or bushes. The absence of broad-leafed forest in the Tepalcatepec Valley probably accounts for the absence of this snake in that area. ~Manolepis putnami~ (Jan) _Dromicus putnami_ Jan, Elenco sistematico degli Ofidi, p. 67, 1863.--San Blas, Nayarit, México. _Manolepsis putnami_, Smith and Taylor, Bull. U. S. Natl. Mus., 187:92, October 5, 1945. La Placita (3); Maquili; Ostula. In Michoacán the species has been found only in tropical semi-deciduous forest on the lower slopes of the Sierra de Coalcomán. From the observations made by Peters (1954:28), this snake is diurnal and feeds on teiid lizards. ~Masticophis striolatus striolatus~ Mertens _Coluber striolatus_ Mertens, Zoologica (Stuttgart), 32:190, 1934.--Substitute name for _Coluber lineatus_ Bocourt, a secondary homonym of _Coluber lineatus_ Linnaeus = _Lygophis lineatus_. Type locality restricted to Presidio de Mazatlán, Sinaloa, México, by Smith and Taylor (1950a:343). _Masticophis striolatus striolatus_, Zweifel and Norris, Amer. Midl. Nat., 54:242, July, 1955. Apatzingán (4); Arteaga; Coalcomán (3); El Sabino; Jiquilpan; La Palma; La Playa (3); Lombardia; Nueva Italia; Río Cachán; Santa Ana; Uruapan (2); Volcán Jorullo; Ziracuaretiro. This large diurnal species inhabits open scrub forest and cultivated terrain from sea level to about 1650 meters. On the Mexican Plateau it is known from the area around Lago de Chapala, to which it possibly gained access through the valleys in the headwaters of the Tepalcatepec drainage. Specimens from southern Michoacán have been reported previously by Peters (1954:28) and Duellman (1954b:16) as _Masticophis flagellum lineatus_. ~Masticophis taeniatus australis~ Smith _Masticophis taeniatus australis_ Smith, Jour. Washington Acad. Sci., 31:390, September 11, 1941.--Guanajuato, Guanajuato, México. Tacícuaro (2); Zamora. This species reaches the southern limit of its distribution in the state of Michoacán. The limited ecological data available suggest that the species inhabits the open mesquite grassland of the Mexican Plateau. ~Oxybelis aeneus auratus~ (Bell) _Dryinus auratus_ Bell, Zool. Jour., 2:324, 1825.--México. Type locality restricted to Tehuantepec, Oaxaca, México, by Smith and Taylor (1950a:340). _Oxybelis aeneus auratus_, Bogert and Oliver, Bull. Amer. Mus. Nat. Hist., 83:381, March 30, 1945. Coahuayana; El Sabino (4); between Las Tecatas and Las Higuertas; between Los Pozos and La Ciénega; Playa Azul; Pómaro (2); between Pómaro and Maruata (2); Punto San Telmo; Río Tizupan. On the basis of the number of specimens seen and collected on the seaward slopes of the Sierra de Coalcomán, this is a common snake there. Most specimens were collected in tropical semi-deciduous forest; others were collected in oak forest to an elevation of 1700 meters. Apparently _Oxybelis_ does not inhabit the lower parts of the Tepalcatepec Valley; the only specimens from the inland area are four from El Sabino, which is situated at about 900 meters on the slopes of the Cordillera Volcánica. One individual was seen in gallery forest near Limoncito at an elevation of 730 meters on the northern slopes of the Sierra de Coalcomán. ~Pituophis deppei deppei~ (Duméril) _Elaphis deppei_ Duméril, Mem. Acad. Inst. France, 23:453, 1835.--México. Type locality restricted to San Juan Teotihuacán, México, México, by Smith and Taylor (1950a:334). _Pituophis deppei deppei_, Stull, Occ. Pap. Mus. Zool. Univ. Michigan, 250:1, October 12, 1932. Carapan (2); Morelia; Tacámbaro; Tacícuaro; Zacapu. Duellman (1960b) showed that the widespread species _Pituophis deppei_ was composite and that the "lined subspecies" actually represented another species, _Pituophis lineaticollis_. _Pituophis deppei_ occurs only on the Mexican Plateau; in Michoacán it inhabits mesquite grassland and oak-bunch grass associations between 1900 and 2200 meters. ~Pituophis lineaticollis lineaticollis~ (Cope) _Arizona lineaticollis_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 13:300, December 28, 1861.--Southern Mexican Plateau. Type locality restricted to 24 kilometers northwest of Oaxaca, Oaxaca, México, by Duellman (1960b:607). _Pituophis lineaticollis lineaticollis_, Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 10:607, May 2, 1960. Acuaro de las Lleguas; Dos Aguas (3); Morelia; Tancítaro (5). This species reaches the northern limits of its range in the Sierra de Coalcomán and on the Mexican Plateau in Michoacán. On the plateau it has been collected in mesquite grassland at elevations between 1500 and 2000 meters. In the Sierra de Coalcomán individuals were found in open pine-oak forest at 2100 meters elevation and in a meadow surrounded by pine-oak forest at 2300 meters. ~Pseudoficimia frontalis~ (Cope) _Toluca frontalis_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:167, September 30, 1864.--Colima, Colima, México. _Pseudoficimia frontalis_, Günther, Biologia Centrali-Americana, Reptilia, p. 96, May, 1893. Apatzingán; Coalcomán (6); El Sabino (2). Most specimens were found beneath rocks in grassy areas near the upper limits of the arid scrub forest, both in the Sierra de Coalcomán and on the southern slopes of the Cordillera Volcánica; all are from elevations of less than 1100 meters. One specimen was found on a road at night near Apatzingán. This species has been found in similar habitats near Huajintlán, Guerrero, and in arid scrub forest at lower elevations in Colima. It is unknown from the coast of Michoacán. ~Pseudoficimia pulcherrima~ Taylor and Smith _Pseudoficimia pulcherrima_ Taylor and Smith, Univ. Kansas Sci. Bull., 28:246, May 15, 1942.--Huajintlán, Guerrero, México. Apatzingán. This specimen (CNHM 39208) was reported by Schmidt and Shannon (1947:81); they stated that it was a paratype of _P. pulcherrima_. However, Taylor and Smith (1942a:246) did not mention the specimen; aside from the type (EHT-HMS 5497), the only other specimen they designated as belonging to the type series was UMMZ 85711 from Chilpancingo, Guerrero. The taxonomic validity of _Pseudoficimia pulcherrima_ remains doubtful, for only minor characters distinguish it from _P. frontalis_. Furthermore, all known specimens of _P. pulcherrima_ are from within the geographic range of _P. frontalis_. ~Rhadinaea hesperia hesperia~ Bailey _Rhadinaea hesperia_ Bailey, Occ. Pap. Mus. Zool. Univ. Michigan, 412:8, May 6, 1940.--Omilteme and Sierra de Burro, Guerrero. Type locality restricted to Omilteme, Guerrero, México, by Smith and Taylor (1950a:332). _Rhadinaea hesperia hesperia_, Smith, Proc. Biol. Soc. Washington, 55:185, December 31, 1942. Arteaga (3); Coalcomán; El Sabino (2); Uruapan; Volcán Jorullo (2). One specimen from Volcán Jorullo (UMMZ 104494), three from Arteaga (UMMZ 119281), and one from Uruapan (UMMZ 92342) are typical of the subspecies _R. h. hesperia_ in possessing a lateral cream-colored line on the sixth and parts of the fifth and seventh dorsal scale rows and in lacking a dark line on the second scale row. The specimens from El Sabino (EHT-HMS 5441 and UIMNH 18933) and one from Coalcomán (UMMZ 104502) have the cream-colored line on the sixth and adjacent parts of the fifth and seventh scale rows and have a dark line on the second scale row. Another individual from Volcán Jorullo (UMMZ 104682) has cream-colored lines like the others, but it possesses two lateral dark lines, one on the second scale row, and one on the third. Smith (1942d:186) diagnosed _Rhadinaea hesperia hesperioides_ as differing from the nominal subspecies in having the cream-colored line on the fourth and fifth scale rows and in possessing a dark line on the second scale row. The specimens seen all have the lateral cream-colored line centered on the sixth scale row, as is characteristic of _R. h. hesperia_. Although many of the specimens also possess a dark line on the second scale row, these specimens are here assigned to _R. h. hesperia_. Additional specimens are necessary to define accurately the subspecies and their ranges. Peters (1954:29) assigned the specimens from Coalcomán to _R. h. hesperioides_. In life the specimens from Arteaga had bright cream-colored temporal stripes and dorsolateral stripes on the anterior part of the body. The chin and anterior one-sixth of the belly was white; posteriorly the venter was bright orange-red. In Michoacán this snake has been found in tropical semi-deciduous forest, arid scrub forest, and pine-oak forest at elevations from 850 to 1500 meters. ~Rhadinaea laureata~ (Günther) _Dromicus laureatus_ Günther, Ann. Mag. Nat. Hist., ser. 4, 1:419, 1868.--Mexico City. _Rhadinaea laureata_, Boulenger, Catalogue Snakes... British Museum, 2, p. 179, September 23, 1894. Capácuaro; Carapan (8); Cherán (3); Paracho (2); Pátzcuaro; Tancítaro (10). This snake is abundant in the Cordillera Volcánica, but it is unknown in the mountains to the northeast of Morelia or in the Sierra de Coalcomán. Most specimens were found beneath volcanic rocks imbedded in the ashy soil in pine forest between 1800 and 2300 meters. ~Rhadinaea taeniata~ (Peters) _Dromicus taeniatus_ Peters, Monats. Akad. Wiss. Berlin, p. 275, 1863.--México. _Rhadinaea taeniata_, Bailey, Occ. Pap. Mus. Zool. Univ. Michigan, 412:14, May 6, 1940. Tancítaro (2). This species, which is known only from a small region in the mountains of Jalisco and central Michoacán, is represented by two specimens (CNHM 37130 and 39030) collected at Tancítaro (see Schmidt and Shannon, 1947:80). ~Salvadora bairdi~ Jan _Salvadora Bairdii_ Jan. Icon. gener. ophid., livr. 2, pl. 3, fig. 2, 1860.--México. Type locality restricted to Acámbaro, Guanajuato, México, by Smith and Taylor (1950a:330). Barranca Seca; Carapan; Cerro San Andrés; Cojumatlán (2); Jiquilpan; Morelia; Pátzcuaro (4); Quiroga; Sahuayo (2); Tacícuaro (12); Tancítaro (56); Uruapan (2); Zacapu (2); between Zitácuaro and Tuxpan (3). This species is abundant on the Mexican plateau, where it inhabits the more grassy areas in the mesquite grassland and cutover land in the pine forests from 1550 to 2500 meters. Davis and Dixon (1957:21) described a specimen from Zacapu as having two dark paravertebral stripes diverging on the temporals and extending through the eye onto the loreal, a characteristic of _Salvadora lineata_. On the basis of this specimen, Davis and Dixon suggested that _Salvadora bairdi_ and _S. lineata_ were subspecifically related. The examination of the large number of specimens from Michoacán has revealed this kind of coloration in only one other specimen, an individual from Tacícuaro, in which the stripes diverge, but do not extend through the eye onto the loreal. Data on scutellation for the large series from Tancítaro were given by Schmidt and Shannon (1947:78), and for the series from Tacícuaro by Smith (1943:466). ~Salvadora mexicana~ (Duméril, Bibron, and Duméril) _Zamenis mexicanus_ Duméril, Bibron, and Duméril, Erpétologie genérale, 7 (pt. 1), p. 695, 1854.--Cape Corrientes, Jalisco, México. _Salvadora mexicana_ Günther, Ann. Mag. Nat. Hist., ser. 3, 12:349, 1863. Apatzingán (12); Capirio (2); El Sabino (5); Huetamo; La Placita; La Playa (4); Lombardia; Nueva Italia; Ojos de Agua de San Telmo; Oropeo; Río Cancita, 14 km. E of Apatzingán; Santa Ana. This is one of the most abundant snakes in the arid lowlands of the Tepalcatepec Valley; observations indicate that it probably is equally abundant on the coastal lowlands. Near Apatzingán as many as five of these snakes have been seen in one-half hour. The snakes seem to be equally abundant and active in the dry season and in the rainy season. Most individuals were seen on the ground, but two were found in low trees. On several occasions _Salvadora mexicana_ was observed in pursuit of lizards on the ground. Captured individuals regurgitated _Cnemidophorus costatus zweifeli_, _Cnemidophorus deppei infernalis_, _Sceloporus horridus oligoporus_, _Sceloporus pyrocephalus_, and _Urosaurus gadowi_. _Salvadora mexicana_ inhabits only the arid scrub forest at elevations from sea level to about 1000 meters. ~Sibon nebulatus~ (Linnaeus) _Coluber nebulatus_ Linnaeus, Systema naturae, ed. 10, 1, p. 222, 1758.--Africa (in error). Type locality restricted to Jicaltepec, Veracruz, México, by Smith and Taylor (1950a:349). _Sibon nebulatus_, Taylor, Univ. Kansas Sci. Bull., 26:473, November 27, 1940. Aquila. The one specimen from Michoacán was collected by Peters (1954:30) in tropical semi-deciduous forest on the coastal foothills of the Sierra de Coalcomán. As presently known, the range of this species in western México extends from Chiapas to Nayarit. Throughout this region the species avoids scrub forest; this may explain its absence in the Balsas-Tepalcatepec Valley. ~Sonora michoacanensis michoacanensis~ (Dugès) _Contia michoacanensis_ Dugès, _in_ Cope, Proc. Amer. Philos. Soc., 22:178, 1885.--Michoacán. Type locality restricted to Apatzingán, Michoacán, México, by Smith and Taylor (1950a:335). _Sonora michoacanensis michoacanensis_, Stickel, Proc. Biol. Soc. Washington, 56:116, October 19, 1943. Apatzingán (3); Coalcomán (3); 12 km. S of Tzitzio. These specimens, together with all known specimens from the Sierra del Sur in Guerrero (KU 23790-1, MVZ 45123) and the upper Balsas Basin in Puebla (UIMNH 41688), are referable to _S. m. michoacanensis_. The dorsal pattern consists of a highly variable number of cross-bands of red, white, and black. In the specimens from Michoacán there are as many as 17 red cross-bands on the body. One specimen from Apatzingán (CNHM 37141) has just behind the head a white band, bordered on either side by a narrow black band; posteriorly the body is uniform red. Two specimens from Coalcomán (UMMZ 109905-6) have respectively 11 and 13 red cross-bands and 20 and 17 white cross-bands, and the posterior part of the body is devoid of red color. Other specimens from these localities have red, black, and white cross-bands throughout the length of the body. _Sonora michoacanensis michoacanensis_ is distinguished from _S. michoacanensis mutabilis_ by the presence of cross-bands on the tail in the latter (Stickel, 1943:116). One specimen from Coalcomán (UMMZ 109904) has one narrow band on the tail; all others from Michoacán have uniformly red tails. Apparently _Sonora michoacanensis michoacanensis_ ranges in semi-arid and arid habitats from the upper Balsas Basin in Puebla westward to the lower slopes of the Sierra de Coalcomán, whereas _S. m. mutabilis_ lives in foothills of the Sierra Madre Occidental from southern Jalisco to Nayarit. Zweifel (1959b:6) presented evidence to show that specimens of _S. m. mutabilis_ supposedly from "Distrito Federal" probably bear erroneous locality data. ~Tantilla bocourti~ (Günther) _Homalocranium bocourti_ Günther, Biologia Centrali-Americana, Reptilia, p. 149, 1895.--Guanajuato, Guanajuato, México. _Tantilla bocourti_, Cope, Amer. Nat., 30:1021, December, 1896. Carapan; Pátzcuaro (2); between Zitácuaro and Río Tuxpan (11). This small snake is an inhabitant of the coniferous forests and the pine-oak forests on the Cordillera Volcánica. Data on the series from between Zitácuaro and the Río Tuxpan were given by Taylor (1940c:481). ~Tantilla calamarina~ Cope _Tantilla calamarina_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 18:320, February 13, 1867.--Guadalajara, Jalisco, México. Apatzingán; La Placita. Although this snake has been collected at high elevations along the rim of the Mexican Plateau in Nayarit, Jalisco, México, and Puebla, the specimens from Michoacán are from arid scrub forest at elevations of less than 400 meters. The species has been found in similar habitats in Colima (Oliver, 1937:24) and in Sinaloa and the Tres Marías Islands (Zweifel, 1960:110). ~Toluca lineata lineata~ Kennicott _Toluca lineata_ Kennicott, _in_ Baird, Report on the United States and Mexican boundary survey, 2, Reptiles, p. 23, 1859.--Valley of México. _Toluca lineata lineata_, Taylor and Smith, Univ. Kansas Sci. Bull., 28:343, May 15, 1942. Capácuaro; Carapan (12); Cherán (23); Cojumatlán; Los Reyes; Morelia (2); Nahuatzen; Paracho (10); Pátzcuaro (17); Uruapan (2). This small snake is an inhabitant of the coniferous forests between elevations of about 1550 and 2800 meters. Not infrequently, individuals have been found in pine-oak forest within these elevations. The generic status of _Toluca_ is unsettled. Taylor and Smith (1942b) separated _Toluca_ from _Conopsis_ by the presence of enlarged and grooved posterior maxillary teeth in _Toluca_ and their absence in _Conopsis_. Bogert and Oliver (1945:378) suggested synonymizing _Toluca_ with _Conopsis_. Smith and Laufe (1945:12) defined the generic position of _Toluca_. Actually, in deciding the generic position of these snakes, five genera (_Ficimia_, _Gyalopion_, _Pseudoficimia_, _Conopsis_, and _Toluca_) must be considered. Of these _Ficimia_ and _Gyalopion_ are closely related; they have been placed in one genus by some workers. _Pseudoficimia_ is intermediate between _Ficimia-Gyalopion_ and _Toluca-Conopsis_. A workable definition of the supraspecific classification of these snakes must await a thorough review of the species. ~Trimorphodon biscutatus biscutatus~ (Duméril, Bibron, and Duméril) _Dipsas biscutata_ Duméril, Bibron, and Duméril, Erpétologie genérale, 7 (pt. 2):1153, 1854.--México. Type locality restricted to Tehuantepec, Oaxaca, México, by Smith and Taylor (1950a:340). _Trimorphodon biscutatus biscutatus_, Smith, Proc. U. S. Natl. Mus., 91:159, November 10, 1941. Apatzingán (11); Cofradía; Cuatro Caminos; El Sabino (2); La Placita; La Playa (2); Lombardia (2); Nueva Italia (2); Río Tepalcatepec, 27 km. S of Apatzingán; Tafetán. In the arid lowlands of the Tepalcatepec Valley and presumably also in the scrub forest of the coastal lowlands, this is an abundant snake, which is active only at night. Usually snakes of this species are found on the ground, but one large individual was observed at night in a low tree. That individual defied capture by widely opening its mouth and striking repeatedly at the collector. The excreta of one specimen contained feathers of an unidentified species of bird. ~Trimorphodon latifascia~ Peters _Trimorphodon biscutata latifascia_ Peters, Monats. Akad. Wiss. Berlin, p. 877, 1869.--Puebla, México. Type locality restricted to Izúcar de Matamoros, Puebla, México, by Smith and Taylor (1950a:341). _Trimorphodon latifascia_. Taylor, Univ. Kansas Sci. Bull., 25:364, July 10, 1939. Apatzingán (5); Casada Tzararacua; Coalcomán (2); Lombardia; 14 km. S of Lombardia; Nueva Italia; San Salvador. In Michoacán this species has been collected in semi-arid habitats at elevations from 300 to 1430 meters in the Tepalcatepec Valley and lower slopes of the Cordillera Volcánica. In this area it occurs sympatrically with _Trimorphodon biscutatus biscutatus_. In life, adults have a pale tan dorsal ground color and rich chocolate brown cross-bands; the eye is pale grayish tan. A juvenile from Coalcomán has black cross-bands on a pale grayish tan ground color. As stated by Schmidt and Shannon (1947:83) and Peters (1954:32), the type specimen of _Trimorphodon fasciolata_ Smith from Cascada Tzararacua is indistinguishable from specimens of _Trimorphodon latifascia_. Seven males have 209 to 223 (216.5) ventrals; one female has 227 ventrals. The number of dark cross-bands on the body varies from 12 to 16 (13.5). The relationships of this species are with _Trimorphodon tau_ on the Mexican Plateau. In fact, additional specimens from the headwaters of the Tepalcatepec Valley and the lower slopes of the Mexican Plateau in eastern Michoacán and adjacent Jalisco may show that the two are conspecific. _Trimorphodon latifascia_ differs from _tau_ in having fewer dark cross-bands on the body and in lacking an interocular bar. ~Trimorphodon tau~ Cope _Trimorphodon tau_ Cope, Proc. Amer. Philos. Soc., 11:151, 1869.--Quiotepec, Oaxaca, México. Emiliano Zapata (2); between Morelia and Ciudad Hidalgo; Tacícuaro; Tangamandapio. Two of the specimens from Michoacán (UMMZ 118948 from Tangamandapio and UIMNH 19138 from Tacícuaro) have cream-colored, Y-shaped marks on the head. These markings supposedly are characteristic of _Trimorphodon upsilon_. One specimen from Emiliano Zapata (UMMZ 118950) and one from between Morelia and Ciudad Hidalgo (EHT-HMS 21402) have a cream-colored line on the parietal suture; in another specimen from Emiliano Zapata (UMMZ 118949) the anterior end of this line is expanded, giving the appearance of an incipient "Y". Thus, the nature of the markings on the head in specimens from Michoacán is intermediate between the typical condition in _Trimorphodon tau_ and the usual condition in _T. upsilon_. Smith and Taylor (1945:148) gave the range of _Trimorphodon tau_ as: "Central Guerrero, in the Sierra Madre del Sur; central Oaxaca; and the edge of the plateau in central Michoacán." They gave the range of _Trimorphodon upsilon_ as: "Southern Chihuahua south to central Michoacán, east to central Hidalgo." Specimens referable to _T. tau_ have been found at La Joya de Salas, near Ciudad Victoria, and near Llera, Tamaulipas (see Smith and Darling, 1952:85, and Martin, 1958:74). Some of these specimens also show combinations of characteristics of _T. tau_ and _T. upsilon_. Smith and Darling (_loc. cit._) suggested that _T. tau_ and _T. upsilon_ be considered as subspecies. However, if _T. tau_ and _T. upsilon_ are subspecies, intergrades would be expected between the ranges of the two populations and not on the northeastern and southwestern periphery of their combined ranges. Instead, the limited evidence now available suggests that _T. tau_ and _T. upsilon_ are names based on a highly variable character of color pattern of the head, and that only one species is involved. In Michoacán this species inhabits the mesquite grassland on the Mexican Plateau. ~Tropidodipsas occidentala~ Oliver _Tropidodipsas occidentala_ Oliver, Occ. Pap. Mus. Zool. Univ. Michigan, 360:20, November 20, 1937.--Comala, Colima, México. Coalcomán. This specimen was reported by Peters (1954:34), who found it beneath a rock at the mouth of a heavily wooded ravine near Coalcomán at an elevation of 950 meters. The only other known specimen is from Comala, Colima, a village, like Coalcomán, that is located near the upper limits of the arid scrub forest. ~Natrix valida isabelleae~ Conant _Natrix valida isabelleae_ Conant, Nat. Hist. Misc., 126:7, September 15, 1953.--Pie de la Cuesta, Laguna Coyuca, Guerrero, México. Coahuayana; Playa Azul (2); Punto San Juan de Lima. Three females and one male have, respectively, 133, 135, 135, and 131 ventrals, and 68, 68, 73, and 75 caudals. The grayish stippling on the posterior ventral surfaces mentioned by Conant (1953:9) is not visible on these specimens. In the small individuals from Punto San Juan de Lima and from Coahuayana there are four longitudinal rows of dark spots on the dorsum; in two large females from Playa Azul the spots are barely discernible. All of the specimens from Michoacán were found in the coastal lowlands; those from Playa Azul were collected from a small brackish, mangrove-lined lagoon. ~Storeria storerioides~ (Cope) _Tropidoclonium storerioides_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 17:190, December 26, 1865.--Mexican Plateau. Type locality restricted to Tres Cumbres, Morelos, México, by Smith and Taylor (1950a:336). _Storeria storerioides_, Garman, Mem. Mus. Comp. Zool., 8(3):29, June, 1883. Dos Aguas (11); Puerto de Garnica; Tancítaro (11); Tzitzio; Uruapan; 16 km. NW of Zacapu. Three males and six females from the Sierra de Coalcomán have, respectively, 122-128 (125.3) and 126-136 (130.0) ventrals, and 46-47 (46.7) and 38-42 (39.1) caudals. Four males and eleven females from the Cordillera Volcánica have, respectively, 124-132 (128.5) and 127-139 (136.4) ventrals, and 43-48 (44.7) and 38-44 (40.2) caudals. These data show that, although there is little difference in the number of caudals, specimens from the Sierra de Coalcomán have fewer ventrals than do specimens from the Cordillera Volcánica. Of eleven specimens from the Sierra de Coalcomán, two have black bellies. Five others from the Sierra de Coalcomán and one from Puerto de Garnica in the Cordillera Volcánica have the bellies heavily stippled with black, giving a gray appearance. Melanistic tendencies in this species have been discussed by Anderson (1960:64), who examined the specimen from Tzitzio. In life, one specimen from Dos Aguas (UMMZ 119451) had a cream-colored belly; the edges of the ventrals were dark brick-red. In Michoacán this snake inhabits pine-oak, pine, and fir forests at elevations between 1550 and 2800 meters in the Cordillera Volcánica and the Sierra de Coalcomán. Most specimens were found beneath rocks; the one from Tzitzio was removed from the stomach of a Mexican Motmot (Anderson, 1960:66). ~Thamnophis dorsalis cyclides~ Cope _Thamnophis cyrtopsis cyclides_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 13:299, December 28, 1861.--Cape San Lucas, Baja California (in error). Type locality restricted to Guanajuato, Guanajuato, México, by Smith and Taylor (1950a:330). Smith, Copeia, no. 2:140, June 8, 1951. Milstead, Texas Jour. Sci., 5:368, September, 1953. _Thamnophis eques eques_ (_nec._ Reuss), Smith, Zoologica, 27:106, October 23, 1942. Bogert and Oliver, Bull. Amer. Mus. Nat. Hist., 83:356, March 30, 1945. _Thamnophis vicinus_ Smith, Zoologica, 27:104, October 23, 1942.--Temazcal, Michoacán, México. _Thamnophis dorsalis cyclides_, Fitch and Milstead, Copeia, no. 1:112, March 17, 1961. Barolosa; Coalcomán; Dos Aguas (3); Los Reyes; Morelia (16); Opopeo; Pino Gordo; Tacícuaro (16); Tancítaro (14); Tangamandapio (2); Temazcal (2); Tzintzuntzan; Uruapan. The snakes comprising the former _Thamnophis eques_-group have undergone extensive taxonomic and nomenclatural shuffling by Smith (1942 and 1951), Bogert and Oliver (1945), Milstead (1953), and Fitch and Milstead (1961). Smith recognized in Michoacán three members of the _T. eques_ (= _dorsalis_) complex: _eques eques_, _eques postremus_, and _vicinus_. Later, Smith (1951) showed that the specific name _eques_ had been misapplied, so that _T. eques eques_ became _T. cyrtopsis cyclides_, and _T. eques postremus_ became _T. cyrtopsis postremus_; under this arrangement _T. vicinus_ stood unchanged. In the meantime, Bogert and Oliver (1945:359) presented a reinterpretation of Smith's data and suggested that _T. vicinus_, which differs from _T. dorsalis cyclides_ only in lacking a middorsal stripe, "... is not a species, but only a pattern phase, possibly a simple mutant of _T. e. eques_" (= _T. dorsalis cyclides_, by present arrangement). Milstead (1953) agreed with Bogert and Oliver on the status of _T. vicinus_; furthermore, on the basis of only a few specimens, Milstead concluded that _T. cyrtopsis postremus_ was not subspecifically distinct from _T. cyrtopsis cyclides_. Recently, Fitch and Milstead (1961) showed that _Thamnophis dorsalis_ Baird and Girard (1853) was the correct name for the snakes that had been recognized as _Thamnophis cyrtopsis_ Kennicott (1860). Consequently, the snakes referred to _T. eques eques_ by Smith (1942) and to _T. cyrtopsis cyclides_ by Smith (1951) and Milstead (1953) are now _T. dorsalis cyclides_. Aside from one specimen from Temazcal and nine from Morelia (paratypes of _T. vicinus_), only two other specimens completely lacking the middorsal stripe have been seen; one is a male (UMMZ 102510) having 161 ventrals and an incomplete tail from Pino Gordo, and the other is a male (CNHM 39060) from Tancítaro having 158 ventrals and an incomplete tail. A female from Tancítaro (CNHM 39061) having 153 ventrals and 77 caudals has no lateral stripes and only a narrow middorsal stripe on the anterior part of the body. Throughout the region where _T. vicinus_-like snakes have been found, typical _T. dorsalis cyclides_ occurs in much greater numbers. I concur with Bogert and Oliver in placing _T. vicinus_ as a synonym of _T. dorsalis cyclides_. [Illustration: FIG. 10. Dorsal color pattern of _Thamnophis dorsalis cyclides_ (A) and _Thamnophis dorsalis postremus_ (B).] Milstead (1953) had available few specimens of _Thamnophis dorsalis_ from the Tepalcatepec Valley. The large series now in existence shows that the population in the Tepalcatepec Valley differs distinctly from that inhabiting the Mexican Plateau, Cordillera Volcánica, and Sierra de Coalcomán. Therefore the name _T. dorsalis postremus_ Smith (1942) is resurrected for the population in the Tepalcatepec Valley. _T. dorsalis cyclides_ and _T. dorsalis postremus_ differ in color pattern (Fig. 10) and in scutellation (Table 6). Specimens from the Mexican Plateau and mountain ranges have a distinct light stripe on the second and third scale rows, a dark brown dorsum having squarish black spots, and a row of dark spots on the first row of dorsal scales. Specimens from the Tepalcatepec Valley have a grayish brown dorsum having smaller and less distinct dark spots and no light stripe on the second and third scale rows; the first, second, and third rows of scales are colored like the venter. In some specimens there are small dark flecks on the first row of dorsal scales. TABLE 6.--VARIATION IN SCUTELLATION IN THAMNOPHIS DORSALIS. +---------------------------------+-------+---------+------------+ | Character |Mexican|Sierra de|Tepalcatepec| | |Plateau|Coalcomán| Valley | +------------------+--------------+-------+---------+------------+ | Ventrals | Female N | 31 | 2 | 32 | | | Mean | 164.0 | 156.5 | 144.6 | | | Range|153-171| 154-159 | 138-151 | | +--------------+-------+---------+------------+ | | Male N | 19 | 2 | 32 | | | Mean | 153.5 | 154.7 | 138.3 | | | Range|149-159| 149-159 | 131-141 | +------------------+--------------+-------+---------+------------+ | Caudals | Female N | 28 | 2 | 29 | | | Mean | 83.8 | 81.0 | 73.4 | | | Range|80-100 | 79-83 | 70-79 | | +--------------+-------+---------+------------+ | | Male N | 14 | 2 | 28 | | | Mean | 78.0 | 72.0 | 68.5 | | | Range| 71-87 | 72 | 63-73 | +------------------+--------------+-------+---------+------------+ One specimen from Uruapan (1550 meters) and one from Coalcomán (950 meters) are intermediate in color pattern between _T. dorsalis cyclides_ and _T. dorsalis postremus_. Both have indistinct lateral stripes and only small dark spots below the stripes. In scutellation these specimens are like _T. dorsalis cyclides_. In Michoacán _Thamnophis dorsalis cyclides_ has been collected in a variety of habitats on the Mexican Plateau: pine-oak forest, fir forest, marshes, and cleared land from 1550 to 2800 meters. In the Sierra de Coalcomán one was taken in broad-leafed forest at 950 meters, three in pine-oak forest at 2100 meters, and one in pine forest at 2300 meters. ~Thamnophis dorsalis postremus~ Smith _Thamnophis eques postremus_ Smith, Zoologica, 27:109, October 23, 1942.--El Sabino, Michoacán, México. _Thamnophis cyrtopsis postremus_ Smith, Copeia, no. 2:140, June 8, 1951. _Thamnophis cyrtopsis cyclides_ (part), Milstead, Texas Jour. Sci., 5:368, September, 1953. _Thamnophis dorsalis postremus_, Fitch and Milstead, Copeia, no. 1:112, March 17, 1961. Apatzingán (31); Capirio (2); Charapendo; Cuatro Caminos (22); El Sabino; Lombardia (9); Nueva Italia (8); Uruapan (3). The reasons for recognizing the population of _Thamnophis dorsalis_ in the Tepalcatepec Valley as distinct from that on the surrounding highlands are presented in the discussion of _Thamnophis dorsalis cyclides_. In certain features of coloration and in the low numbers of ventrals and caudals, _T. dorsalis postremus_ shows more resemblance to _T. dorsalis sumichrasti_ than to _T. dorsalis cyclides_. According to Milstead (1953:367), _T. dorsalis cyclides_ ranges southward from the Río Balsas in southwestern México. If specimens could be obtained from the upper Balsas Basin they might show that _T. dorsalis postremus_ inhabits that extensive basin. In the Tepalcatepec Valley _T. dorsalis postremus_ is most frequently found at night in the rainy season, at which time the snakes are abundant near temporary pools where frogs are breeding. The absence of specimens from the coastal lowlands of Guerrero, Michoacán, and Colima indicate that, although the species inhabits the lowlands of the Tepalcatepec Valley, its range does not include the coastal lowlands. A female (UMMZ 119402 from Cuatro Caminos) having 139 ventrals and a body length of 576 mm., on June 20, 1958, gave birth to 25 young, of which 18 (9 males and 9 females) were preserved. In body length the males varied from 132 to 141 (137.3) mm.; the females, 125 to 137 (133.1) mm. In tail length the males varied from 38 to 44 (42.4) mm.; females, 35 to 42 (39.7) mm. The males have 138 to 147 (142.2) ventrals and 70 to 75 (72.9) caudals; females have 131 to 140 (135.8) ventrals and 63 to 71 (67.0) caudals. ~Thamnophis eques eques~ (Reuss) _Coluber eques_ Reuss, Zool. Misc., p. 152, 1834.--México. Type locality restricted to Guadalajara, Jalisco, México, by Smith and Taylor (1950a:334). _Thamnophis macrostemma macrostemma_, Smith and Taylor, Bull. U. S. Natl. Mus., 187:163, October 5, 1945. _Thamnophis subcarinata subcarinata_, Smith, Herpetologica, 5:63, May 31, 1949. _Thamnophis eques eques_, Smith, Copeia, no. 2:139, June 8, 1951. Jiquilpan; Lago de Cuitzeo; Lago de Pátzcuaro (17); Pátzcuaro (5); Tangancícuaro; Tupátaro (2); Undameo; Zacapu. Although this snake has been collected in open pine-oak forest and in oak-bunch grass associations, it seems to reach its greatest abundance in marshes on the Mexican Plateau at elevations of 1550 to 2300 meters. ~Thamnophis melanogaster canescens~ Smith _Thamnophis melanogaster canescens_ Smith, Zoologica, 27:117, October 23, 1942.--Chapala, Jalisco, México. Lago de Cuitzeo (5); Lago de Pátzcuaro; Pátzcuaro; Tacícuaro; Tangamandapio (2). This species of garter snake seems to be most abundant in the marshes adjacent to the lakes on the Mexican Plateau in Michoacán and Jalisco. At these elevations (1550 to 2200 meters) it often is found in association with _Thamnophis eques eques_ and sometimes with _Thamnophis dorsalis cyclides_. On June 11, 1958, individuals of this species were found in a hyacinth-choked marsh at Tangamandapio at night. One specimen from Tangamandapio (UMMZ 119414) had, in life, a dark chocolate brown dorsum, reddish brown sides, and cream-colored belly, chin, and labials. There were no longitudinal dorsal stripes. ~Thamnophis scalaris scaliger~ (Jan) _Tropidonotus scaliger_ Jan, Elenco sistematico degli Ofidi, p. 70, 1863.--No type locality designated. Type locality restricted to Mexico City, Distrito Federal, by Smith and Taylor (1950a:329). _Thamnophis scalaris scaliger_, Smith, Zoologica, 27:103, October 23, 1942. Cerro Tancítaro (2); Nahuatzen; Opopeo; 26 km. S of Pátzcuaro. The few specimens of this species from Michoacán have been collected at elevations from 1800 to 3400 meters in pine or fir forest in the Cordillera Volcánica. ~Micrurus distans michoacanensis~ (Dugès) _Elaps diastema michoacanensis_ Dugès, La Naturaleza, ser. 2, 1:487, 1891.--Michoacán. Type locality restricted to Apatzingán, Michoacán, México, by Smith and Taylor (1950a:335). _Micrurus distans michoacanensis_, Zweifel, Amer. Mus. Novitates, 1953:11, June 26, 1959. Apatzingán (6). All specimens were collected in the arid scrub forest of the Tepalcatepec Valley. The number of black rings on the body varies from six to eleven. In this respect they agree with the diagnosis of this subspecies presented by Zweifel (1959b:9). ~Micrurus laticollaris~ (Peters) _Elaps marcgravii laticollaris_ Peters, Monats. Akad. Wiss. Berlin, p. 877, 1869.--Izúcar de Matamoros, Puebla, México. _Micrurus laticollaris_, Schmidt, Publ. Field Mus. Nat. Hist., zool. ser., 20:39, December 11, 1933. El Sabino (2); Lombardia. This species ranges throughout the Balsas-Tepalcatepec Basin westward into Colima; specimens from Michoacán were collected in arid scrub forest at elevations from 500 to 1050 meters. The limited observations on _Micrurus distans michoacanensis_ and _M. laticollaris_ indicate that, at least in the Tepalcatepec Valley, _M. laticollaris_ seems to inhabit slightly more mesic areas than does _M. distans michoacanensis_. ~Pelamis platurus~ (Linnaeus) _Anguis platura_ Linnaeus, Systema naturae, ed. 12, 1:391, 1766.--Pine Island, Pacific Ocean. _Pelamis platurus_, Gray, Ann. Philos., p. 15, 1825. Boca de Apiza. In November, 1955, Alfonzo Gonzales, a geographer from the University of Texas, observed sea snakes on the beaches of Michoacán. In May, 1956, Donald D. Brand of the University of Texas gave me one specimen of _Pelamis platurus_ that he obtained on March 2, 1956, at Boca de Apiza. Furthermore, he supplied me with the following observations based on his field work along the coast of Michoacán from the Río Coahuayana to Maruata from March 1, to April 15, 1956. At that time many sea snakes were observed; in some places living and dead individuals were seen on the beaches; innumerable snakes were seen in the surf. When live individuals were taken from the beach and thrown into the ocean, they usually swam to shore. Many partially eaten individuals were seen protruding from crab holes. Inquiries among the natives resulted in the following information: Sea snakes are frequently seen between November and April, but most commonly in March and April, at which time the water is cold. The natives referred to the sea snakes as "culebra del mar." Most natives said that the snakes were not poisonous; others did not know of any venomous properties. In May, 1956, I worked the coastal region from the Río Coahuayana to La Placita and saw no sea snakes. In the summer of 1950 James A. Peters, and in the summer of 1951 I worked nearly the entire coastal region of Michoacán; during that time no _Pelamis_ were seen. Insofar as I know, this is the first report of such seasonal activity in _Pelamis platurus_ in the Americas. ~Agkistrodon bilineatus bilineatus~ Günther _Ancisdrodon bilineatus_ Günther, Ann. Mag. Nat. Hist., ser. 3, 12:364, 1863.--Pacific coast of Guatemala. _Agkistrodon bilineatus bilineatus_, Burger and Robertson, Univ. Kansas Sci. Bull., 34 (1):213, October 1, 1951. Apatzingán; El Sabino; La Playa; Los Reyes. All specimens from Michoacán are from inland localities between 300 and 1500 meters. The one from Los Reyes (USNM 46416) was collected by Nelson and Goldman on February 13, 1903. The elevation of Los Reyes (1500 meters) seems unusually high for this species, but otherwise there is no reason to doubt the authenticity of the record. Goldman (1951:192) in his description of Los Reyes stated: "Los Reyes is near the boundary between the Lower Austral and Arid Upper Tropical Zones but is preponderantly tropical in zonal character. The regular crops are mainly sugar cane, rice, and corn." Thus the biotic features of the area are not noticeably different from those at El Sabino and La Playa at lower elevations. The development of extensive agriculture through irrigation in the Tepalcatepec Valley and planting of rice and sugar-cane in that area may produce a more widespread habitat for this snake. The absence of specimens from the coastal lowlands is due solely to inadequate collecting; the natives there know the snake and report that it is not uncommon in certain areas. ~Crotalus basiliscus basiliscus~ (Cope) _Caudisonia basilisca_ Cope, Proc. Acad. Nat. Sci. Philadelphia, September 30, 1864.--Colima. Type locality restricted to Colima, Colima, México, by Smith and Taylor (1950a:328). _Crotalus basiliscus basiliscus_, Gloyd, Nat. Hist. Misc., 17:1, April 23, 1948. Apatzingán (4); Camachines; Coalcomán; El Ticuiz. Specimens from southern Michoacán have fewer ventrals and caudals than do those from the northern part of the range; three males and three females have, respectively, 178, 182, 182, 185, 186, and 188 ventrals, and 27, 28, 29, 22, 29, and 29 caudals. Klauber (1952:81) gave the following data for _Crotalus basiliscus_ (based on specimens from the entire range, except Oaxaca): ventrals in males, 179-201 (191.4), in females, 185-206 (197.6); caudals in males, 26-36 (30.7), in females, 21-29 (24.4). Klauber (1952:84) remarked that the one specimen that he had seen from Apatzingán had fewer ventrals and caudals than most other specimens. The low numbers of ventrals and caudals in specimens from Michoacán, as compared with more northern populations, may be indicative of a trend in the reduction of the numbers of these scutes from north to south. The southernmost examples of _Crotalus basiliscus_ (_Crotalus basiliscus oaxacus_ from Oaxaca) have 172-175 ventrals and 21 caudals (Gloyd, 1948). In Michoacán _Crotalus basiliscus basiliscus_ has been found in arid habitats on the coast, in the Tepalcatepec Valley, and in the lower parts of the Sierra de Coalcomán. All specimens are from localities below 1070 meters in elevation. ~Crotalus durissus culminatus~ Klauber _Crotalus durissus culminatus_ Klauber, Bull. Zool. Soc. San Diego, 26:65, August 8, 1952.--El Sabino, Michoacán, México. El Sabino (18). These specimens are part of the type series and were collected by Hobart M. Smith near the upper limits of the arid scrub forest at an elevation of about 1050 meters on the lower slopes of the Cordillera Volcánica at the northern edge of the Tepalcatepec Valley. They were discussed in detail by Klauber (1952:66-70). ~Crotalus intermedius intermedius~ Troschel _Crotalus intermedius_ Troschel, _in_ von Müller, Reisen in Vereiningten Staaten, Canada und Mexico, vol. 3, p. 613, 1865.--Type locality unknown. _Crotalus intermedius intermedius_, Klauber, Bull. Zool. Soc. San Diego, 26:9, August 8, 1952. Cerro Tancítaro. The one specimen is from the pine forests on the Cordillera Volcánica. At the present time this species is known from scattered localities in west-central Veracruz, Oaxaca, Michoacán, and as _Crotalus intermedius omiltemanus_ in Central Guerrero. Apparently it is restricted to montane environments. ~Crotalus molossus nigrescens~ Gloyd _Crotalus molossus nigrescens_ Gloyd, Occ. Pap. Mus. Zool. Univ. Michigan, 325:2, January 28, 1936.--Four miles west of La Colorada, Zacatecas, México. Carapan; Los Conejos; Pátzcuaro; Tacícuaro (5). In Michoacán this species has been found in pine forests between 1550 and 2300 meters in the Cordillera Volcánica. I expected to find it in the Sierra de Coalcomán, but inquiries among the natives living in the pine forests of that mountain range revealed that the people there have no knowledge of a large species of rattlesnake. ~Crotalus polystictus~ (Cope) _Caudisonia polysticta_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 17:191, December 26, 1865.--Tableland of México. Type locality restricted to Tupátaro, Guanajuata, México, by Smith and Taylor (1950a:330). _Crotalus polystictus_ Cope, _in_ Yarrow, Wheeler's Rept. Geog. Geol. Expl. Surv. W. 100th. Mer., vol. 5, p. 533, 1875. Tacícuaro (4); Tupátaro (2). Formerly this species was abundant in the marshes around Lago de Chapala. The draining of these marshes probably resulted in reducing the numbers of these rattlesnakes. The species is known only from the Mexican Plateau at elevations of 1450 to 2400 meters. ~Crotalus pusillus~ Klauber _Crotalus pusillus_ Klauber, Bull. Zool. Soc. San Diego, 26:34, August 8, 1952.--Tancítaro, Michoacán, México. Acuaro de las Lleguas (2); Carapan; Cerro Tancítaro (16); Dos Aguas (12). Aside from the type series of _Crotalus pusillus_ from Cerro Tancítaro and one specimen from Carapan referred to the species by Klauber (1952:38), there are fourteen specimens from the Sierra de Coalcomán. These specimens (UMMZ 112566-7, 118591-9, 118601, 121512-3) are like _Crotalus pusillus_ from Cerro Tancítaro in having the prefrontals paired, a black proximal rattle, and the underside of the tail black. The prefrontals are bordered posteriorly by one scale in two specimens, by two scales in three specimens, and by three scales in the other nine. The snakes from the Sierra de Coalcomán have 40 to 46 (42) dorsal body blotches. Ten males have 150-158 (154.4) ventrals and 29-33 (31.0) caudals; two females have 157 and 160 ventrals, and 25 and 27 caudals. The largest specimen is a male having a body length of 545 mm. and a tail length of 63 mm. The only noticeable difference between the specimens from the Sierra de Coalcomán and the topotypic series is that the latter have fewer dorsal blotches; the range of variation is 33 to 46 (39.8). Most specimens of this species have a grayish brown dorsum and dark brown dorsal blotches. Two specimens from Dos Aguas (UMMZ 118596 and 118599) are pale brown above and have indistinct blotches. One specimen from Dos Aguas regurgitated a large _Gerrhonotus imbricatus imbricatus_; of two others from the same locality, one regurgitated a _Sceloporus bulleri_ and an _Eptesicus fuscus_. The latter specimen was collected at the entrance of a small cave, where it probably had captured the bat. In the Cordillera Volcánica _Crotalus pusillus_ has been obtained in pine-oak forest at elevations between 1550 and 1800 meters. In the Sierra de Coalcomán two specimens were taken in pine forest at an elevation of 2300 meters; ten other were found beneath rocks and logs in pine-oak forest at an elevation of 2100 meters. ~Crotalus triseriatus aquilus~ Klauber _Crotalus triseriatus aquilus_ Klauber, Bull. Zool. Soc. San Diego, 26:24, August 8, 1952.--Alvarez, San Luis Potosí, México. Morelia (10); Tacícuaro (2). I am following Klauber (1952) in assigning some of the specimens of this species from Michoacán to the subspecies _aquilus_ and others to _C. t. triseriatus_. The distinguishing characters of these subspecies are given by Klauber (1952:28). On the basis of the few localities from which the species is known in Michoacán it seems as though _C. t. aquilus_ inhabits the open grassy areas on the Mexican Plateau and the associated open pine-oak or oak-bunch grass habitats to the north and east of the Cordillera Volcánica. _Crotalus triseriatus aquilus_ has been collected at elevations from 1600 to 2000 meters in Michoacán. ~Crotalus triseriatus triseriatus~ (Wagler) _Uropsophus triseriatus_ Wagler, Natürliches System der Amphibien, p. 176, 1830.--México. (Probably Mexico City.) _Crotalus triseriatus triseriatus_, Klauber, Bull. Zool. Soc. San Diego, 26:19, August 8, 1952. Cerro Tancítaro (36); Opopeo; Pátzcuaro. This small rattlesnake inhabits rocky areas in pine and pine-oak forests above 1600 meters in the Cordillera Volcánica; it has been collected at 3270 meters on Cerro Tancítaro. The series reported by Schmidt and Shannon (1947:84) is a mixture of specimens of _Crotalus triseriatus_ and _Crotalus pusillus_. The two species are found together on Cerro Tancítaro, but only _Crotalus pusillus_ inhabits the coniferous forests of the Sierra de Coalcomán. Klauber (1952:30) stated that despite the proximity of _Crotalus triseriatus triseriatus_ and _Crotalus triseriatus aquilus_ in Michoacán, there is no evidence of intergradation. He went on to suggest that additional material might show that the two named populations actually are distinct species. The specimens that have been studied since Klauber's investigations also show no evidence of intergradation, but there still is no known sympatry of the populations. The small montane rattlesnakes belonging to the species _C. pricei_, _C. pusillus_, and _C. triseriatus_ present a problem in systematics and distribution worthy of intensive investigation. A knowledge of the distribution and relationships of the various populations of these snakes, together with other species also living in isolated populations on the higher mountains in México, probably will be of great significance in understanding dispersal and differentiation of animals during the Pleistocene. SPECIES OF QUESTIONABLE OCCURRENCE Some species for which there are no authentic records from Michoacán can be expected there on zoogeographic probability. Other species have been recorded from Michoacán, but these records are doubtful for any one of several reasons. Fifteen species of such questionable occurrence are discussed below: ~Syrrhophus modestus modestus~ Taylor _Syrrhophus modestus_ Taylor, Univ. Kansas Sci. Bull., 28:304, May 15, 1942.--Hacienda Paso del Río, Colima, México. _Syrrhophus modestus modestus_, Duellman, Occ. Pap. Mus. Zool. Univ. Michigan, 594:5, June 6, 1958. This small terrestrial frog is not uncommon on the coastal lowlands and foothills in Nayarit and in Colima, where it has been collected within a few kilometers of the Michoacán border. At Tecolapa, Colima, on August 9, 1956, _Syrrhophus modestus modestus_ was found with _Tomodactylus nitidus orarius_, _Bufo marinus_, _Bufo marmoreus_, _Hyla baudini_, _Hyla smithi_, and _Phyllomedusa dacnicolor_, all of which occur on the coastal lowlands of Michoacán. Because of its solitary and secretive habits, _Syrrhophus modestus modestus_ is not common in collections. Additional field work on the coast of Michoacán should reveal the presence of the species there. ~Hyla microcephala sartori~ Smith _Hyla microcephala sartori_ Smith, Herpetologica, 7:186, December 31, 1951.--1 mi. N of Organos, S of El Triente, Guerrero, México. On August 28, 1960, J. R. Dixon obtained a series of this species from a temporary pond 6 kilometers northeast of La Resolana, Jalisco. Previously, _Hyla microcephala sartori_ had been known only from the lowlands of Guerrero and Oaxaca. The existence of the species in Jalisco provides evidence that this frog also occurs in Michoacán and Colima. ~Gastrophryne usta usta~ (Cope) _Engystoma ustum_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 18:131, 1866.--Guadalajara, Jalisco, México. _Gastrophryne usta usta_, Carvalho, Occ. Pap. Mus. Zool. Univ. Michigan, 555:13, July 16, 1954. Smith and Taylor (1948:93-4) listed specimens of this species from Organos and El Treinta, Guerrero, and from Paso del Río, Quesería, Santiago, and Tecomán, Colima. The species occurs from Sinaloa and central Veracruz southward at low elevations to the Isthmus of Tehuantepec and thence along the Pacific lowlands into Central America. Almost certainly it occurs on the coastal lowlands in Michoacán. Since the amphibian fauna of the Tepalcatepec Valley has been better sampled than that of the coast, I suspect that if _Gastrophryne_ occurred in the Tepalcatepec Valley, I would have found it there. ~Lepidochelys olivacea~ (Eschscholtz) _Chelonia olivacea_ Eschscholtz, Zool. Atlas, pt. 1, p. 2, 1829.--Manila Bay, Philippine Islands. _Lepidochelys olivacea_, Girard, United States Exploring Expedition..., vol. 20, Herpetology, p. 435, 1858. According to Smith and Taylor (1950b: 15), this sea turtle is known from the entire Pacific coast of México; these authors reported the species from Chiapas, Oaxaca, Guerrero, Colima, and Sonora. Although the only sea turtle that I observed in Michoacán is _Chelonia mydas_, others probably do use the sheltered beaches for nesting. The scanty records of sea turtles along the Pacific coast of México indicate that _Chelonia mydas_ and _Lepidochelys olivacea_ are the most abundant species in that region. There are scattered records of _Dermochelys coriacea_, _Caretta caretta_, and _Eretmochelys imbricata_ along the Pacific coast. The occurrence of any of these along the coast of Michoacán is probable. ~Geoemyda pulcherrima pulcherrima~ (Gray) _Emys pulcherrima_ Gray, Catalogue of the Shield Reptiles in British Museum, vol. 1, p. 25.--México. Type locality restricted to Presidio de Mazatlán, Sinaloa, México, by Smith and Taylor (1950b:30). _Geoemyda pulcherrima pulcherrima_, Wettstein, Sitzb. Akad. Wiss. Wien, 143:18, 1934. Smith and Taylor (1950b:30) recorded this species from Sonora, Sinaloa, Nayarit, Colima, and Guerrero; these records indicate that the species probably is distributed along the Pacific coast of México southward from southern Sonora. It unquestionably occurs on the coast of Michoacán. Natives of the coastal lowlands tell of another "tortuga de la tierra" besides _Geoemyda rubida_. In the collections of the Museum of Natural History of the University of Illinois is a specimen of _Geoemyda pulcherrima_ from Mexcala in the Balsas Basin in northern Guerrero. On the basis of this specimen it is highly probable that the species also inhabits the Balsas-Tepalcatepec Basin in Michoacán. ~Pseudemys scripta ornata~ (Gray) _Emys ornata_ Gray, Synopsis reptilium, p. 30, 1831.--Mazatlán, Sinaloa, México. _Pseudemys scripta ornata_, Carr, Herpetologica, 1:135, December 30, 1938. The systematics and distribution of _Pseudemys scripta_ in México and Central America are poorly understood. Smith and Taylor (1950b:32) recorded this turtle from the Pacific lowlands of Sinaloa, Jalisco, Oaxaca, and Chiapas. This species is represented by vicarious populations throughout the Atlantic lowlands of México, northwestern México, over much of the United States, and also in Baja California. Along the Pacific coast of México the species seems to be extremely rare, or, at least, only locally abundant. Since the species has such a wide distribution, and since it occurs on the Pacific lowlands both to the north and to the south of Michoacán, it is reasonable to expect its presence on the coast of Michoacán. Inquiries among the natives living in the Balsas-Tepalcatepec Basin produced only negative evidence about the occurrence of _Pseudemys_ in the Río Tepalcatepec and Río Balsas. I suspect that the best place to search for these turtles on the coast of Michoacán is in the numerous fresh-water lagoons on the coastal plain. ~Caiman crocodilus fuscus~ (Cope) _Perosuchus fuscus_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 20:203, November 9, 1868.--Río Magdalena, Columbia. _Caiman crocodilus fuscus_, Mertens, Senckenbergiana, 26:275, December 22, 1943. Gadow (1930:50) reported that _Caiman sclerops_ (= _Caiman crocodilus fuscus_) inhabited the "tierra caliente" in Michoacán. Smith and Taylor (1950b:212) accepted Gadow's record for the State, although otherwise the species is unknown north of Oaxaca. Peters (1954:10) refuted Gadow's record on the basis that Gadow's collections contained no specimens of _Caiman_. The local name "caiman" refers to both _Crocodylus_ and to _Caiman_, for, in general, the natives do not distinguish between the two. "Caimanes" are reported from along the coast of Michoacán, where the name presumably refers to _Crocodylus acutus acutus_, and in the Balsas-Tepalcatepec Basin (Gadow, 1930:50; Webber, 1946:267). I have seen no specimens of either _Crocodylus_ or _Caiman_ from the Balsas Basin. If crocodilians do occur in the basin, they probably are _Crocodylus acutus acutus_. There is no basis, whatsoever, for including Michoacán in the range of _Caiman crocodilus fuscus_. ~Bipes canaliculatus~ Bonnaterre _Bipes canaliculatus_ Bonnaterre, Encyclopédie méthodique, Erpétologie, p. 68, 1789.--México. Type locality restricted to Mexcala, Guerrero, México, by Smith and Taylor (1950b:39). Dugès (1896:480) reported this species from Morelia, Michoacán. Smith and Taylor (1950b:39), who recorded the species from three localities in the Balsas Basin in Guerrero, rejected Dugès' record. I, too, am unwilling to accept Dugès' record. Nevertheless, the species probably occurs throughout much of the Balsas Basin. This idea is strengthened by comments made by Storm (1939:342): "The last hard drop, that afternoon, was down the great Cerro de los Cajones [southwest of Tacámbaro], and here in the upper forest we came upon... a lizard with front legs and none behind ... the animal with hands and no feet that señor Smith [Hobart M. Smith] was seeking!... They're named _Bipes caniculatus_ (_sic._)." ~Coleonyx elegans nemoralis~ Klauber _Coleonyx elegans nemoralis_ Klauber, Trans. San Diego Soc. Nat. Hist., 10:195, March 9, 1949.--Paso del Río, Colima, México. Klauber (1945:199) and Smith and Taylor (1950b:43) reported this lizard from the coastal lowlands of Colima and Guerrero. Davis and Smith (1953:101) reported it from 8 kilometers northeast of Temilpa, Morelos, in the upper Balsas Basin. Specimens of this lizard have been collected infrequently; the few locality records and limited ecological data indicate that it inhabits dense scrub forest and tropical semi-deciduous forest. _Coleonyx elegans nemoralis_ is to be expected on the coastal lowlands, the seaward foothills of the Sierra de Coalcomán, and on the lower slopes of the Cordillera Volcánica along the northern edge of the Tepalcatepec Valley. ~Phrynosoma orbiculare orbiculare~ (Linnaeus) _Lacerta obricularis_ Linnaeus, Systema naturae, ed. 12, 1:1062, 1789.--México (by inference). Type locality restricted to México, Districto Federal, by Smith and Taylor (1950b:97). _Phrynosoma orbiculare orbiculare_, Smith, Trans. Kansas Acad. Sci., 37:290, 1934. Gadow (1905:213) inferred that _Phrynosoma orbiculare_ occurred at elevations of more than 3000 feet in Michoacán. There are no specimens of this species known from Gadow's collections made in Michoacán. Smith and Taylor (1950b:98) apparently accepted Gadow's statement and recorded the species from Michoacán: "above 3000 feet (Jorullo?)." Reeve (1952:940) somehow misconstrued this statement to read "Jorullo, above Zumpango (Smith and Taylor, 1950b)." Reeve did not indicate on his map (1952:939) that the species occurred in Michoacán. In the most recent review of the species (Horowitz, 1955), no localities are given in Michoacán. Since _Phrynosoma orbiculare_ is known from central Jalisco, Guanajuato, Queretaro, and México, its presence at least in northeastern Michoacán is to be expected, although at the present time there are no specimens known from the state. ~Eumeces brevirostris~ (Günther) _Mabouia brevirostris_ Günther, Proc. Zool. Soc. London, p. 316, August, 1860.--Oaxaca. Type locality restricted to Oaxaca, Oaxaca, México, by Smith and Taylor (1950b:168). _Eumeces brevirostris_, Bocourt, Mission scientifique au Mexique et dans l'Amerique Céntrale. Reptiles, livr. 6, p. 439, 1879. Smith and Taylor (1950b:168) Listed this species: "_Michoacán_: No specific record." I am unaware of any specimen of this skink from the state. As presently recognized, this species contains two subspecies. One of these occurs in the mountains of Oaxaca northward into central Veracruz; the other, _Eumeces brevirostris bilineatus_, occurs in Durango southward to Jalisco, where it inhabits the Sierra Madre Occidental. Possibly the species occurs in the Sierra de los Tarascos in Michoacán. ~Eumeces callicephalus~ Bocourt _Eumeces callacephalus_ Bocourt, Mission scientifique au Mexique et dans l'Amerique Céntrale. Reptiles, livr. 6, p. 431, 1879.--Guanajuato, Guanajuato, México. Dugés (1896) in a paper in which he listed several species of _Eumeces_ in México, reported _Eumeces callicephalus_ from Michoacán, but he gave no specific locality within the state. Michoacán was included in the range of the species by Taylor (1936:298) and by Smith and Taylor (1950b:164). The species definitely is known from southeastern Arizona southward to Guanajuato. It may occur in Michoacán, but, since there are three rather widespread species of _Eumeces_ inhabiting the Mexican Plateau and associated mountain ranges in the northern and northeastern part of Michoacán, interspecific competition might be a reason for the absence of _Eumeces callicephalus_ there. ~Leptodeira septentrionalis polysticta~ Günther _Leptodeira polysticta_ Günther, Biologia Centrali-Americana, Reptilia, p. 172, May, 1895.--Belice, British Honduras. _Leptodeira septentrionalis polysticta_, Duellman, Bull. Amer. Mus. Nat. Hist., 114:72, February 24, 1958. Although this species occurs from sea level to elevations of about 2000 meters from Nayarit southward into Central America, no specimens are known from Michoacán. Smith and Taylor (1945:87) listed the species as occurring in Michoacán, but they had no record on which to base this report. Probably, the species occurs on the coastal lowlands and seaward slopes of the Sierra de Coalcomán. ~Tropidodipsas fasciata guerreroensis~ Taylor _Tropidodipsas guerreroensis_ Taylor, Univ. Kansas Sci. Bull., 26:470; November 27, 1940.--Buena Vista, Guerrero, México. _Tropidodipsas fasciata guerreroensis_, Alvarez del Toro and Smith, Herpetologica, 12:16, March 6, 1956. Dugès (1896:480) reported a snake, questionably of this species, from Uruapan, Michoacán. Taylor (1940c) suggested that on geographic grounds Dugès' record might refer to _T. f. guerreroensis_, which is known definitely only from the type locality. _Tropidodipsas occidentala_ is known from Comala, Colima, and Coalcomán, Michoacán. On zoogeopraphic grounds that species might be found at Uruapan. Since the specimen apparently no longer is extant, the identification cannot be ascertained. ~Micrurus fitzingeri fitzingeri~ (Jan) _Elaps fitzingeri_ Jan, Rev. Mag. Zool., p. 521, 1858.--México. Type locality restricted to Guanajuato, Guanajuato, México, by Smith and Taylor (1950a:330). _Micrurus fitzingeri fitzingeri_, Brown and Smith, Proc. Biol. Soc. Washington, 55:63, June 25, 1942. Smith and Taylor (1945:174) recorded the species from Zamora, Michoacán. Hobart M. Smith (_in litt._) stated that this record was based on a report of _Elaps fulvius_ from Zamora by Dugès (1896:482). Smith guessed that the report was based on a specimen of _Micrurus fitzingeri_. The specimen has not been seen. Although the species is known from Guanajuato and México, until a specimen is available from Michoacán, the species should not be considered part of the herpetofauna of Michoacán. GAZETTEER The localities in Michoacán here listed are those from which specimens were examined as well as other localities mentioned in the text. The localities are arranged alphabetically according to the most definitive word or words in the total name. For example, Lago de Chapala is listed as "Chapala (Lago de)" and Cerro de Tancítaro is listed as "Tancítaro (Cerro de)." Insofar as has been possible, the following information is given for each locality: geographical co-ordinates to the nearest minute of north latitude and west longitude, elevation in meters above mean sea level, a description of its geographical location, type of dominant vegetation, and in some cases comments concerning collecting sites in the vicinity. Distances are in kilometers; all are map (air line) distances, unless otherwise indicated. Many localities visited on mule trips are given as being a certain number of "mule hours" in a general direction from another town or village. In order to reach most of these localities today, one would have to go by mule, and this is the way the muleteers determine their distances. Some of the elevations are taken from maps, but most of them were obtained from one or more readings of altimeters that we carried in the field. The terms used for describing the vegetation are those defined in the section of the natural landscape. [Illustration: FIG. 11. Map of Michoacán showing important localities mentioned in text. Localities not on this map can be located by directions given in the gazetteer.] My primary cartographic sources have been: the provisional edition of maps published by the American Geographic Society (Colima, Guadalajara, México, and San Luis Potosí sheets published between 1933 and 1940), scale 1:1,000,000; the preliminary sheets (Colima, Guadalajara, Guanajuato, and México) published in 1949 with a scale of 1:500,000 of the Carta Geográfica de la República Méxicana (Dirección de Geografía y Meterología, Secretaria de Agricultura y Ganadería); and the Carta de Cuenca Tepalcatepec (Scale 1:250,000) prepared in 1958 by the Comisión del Tepalcatepec, Secretaria de Recursos Hidráulicos. I have visited most of the 181 localities and have gathered data pertaining to vegetation, altitude, and location. I think, nevertheless, that the accuracy of some of the locations and elevations as given in the gazetteer is questionable. This situation can be rectified only by detailed geographic studies. Most of the important towns, villages, rivers, and high mountains are shown on the accompanying map (Fig. 11). Places not shown on this map can be located from directions given in the gazetteer. Acahuata.--Lat. 19° 10', long. 102° 21', elev. 1040 m. A village north of Apatzingán and on the southern slope of Cerro de Tancítaro; transition between arid tropical scrub forest and pine-oak forest; tropical semi-deciduous forest in barrancas. Agua Cerca.--Lat. 19° 06', long. 101° 45', elev. 1550 m. A ranch south-southwest of Ario de Rosales on the road to La Huacana; pine-oak forest. Aguililla.--Lat. 18° 45', long. 102° 47', elev. 860 m.; a town in a low valley in the Sierra de Coalcomán; arid tropical scrub forest. Álamo (El).--Lat. 19° 42', long. 100° 55', elev. 2300 m. A ranch 5 kilometers by road east of El Temazcal; pine-oak forest. Angahuan.--Lat. 19° 33', long. 102° 14', elev. 2440 m. A Tarascan village about 27 kilometers northwest of Uruapan; pine forest. Much of the land is still covered by a deep layer of ashes from the nearby Volcán Parícutin. Apatzingán.--Lat. 19° 06', long. 102° 22', elev. 335 m. The largest town in the Tepalcatepec Valley; arid tropical scrub forest. Apiza (Boca de).--Lat. 18° 42', long. 103° 44', sea level. The name of the mouth of the Río Coahuayana; sandy beach and coco palms. Apo.--Lat. 19° 25', long. 102° 25', elev. 2160 m. A village on the western slope of Cerro de Tancítaro; pine-oak forest. Aquila.--Lat. 18° 32', long. 103° 30', elev. 150 m. A small village on the Río Aquila in the seaward foothills of the Sierra de Coalcomán; tropical semi-deciduous forest. Araparicuaro.--Lat. 19° 22', long. 102° 12', elev. 1525 m. A village 19 kilometers west-southwest of Uruapan on the trail to Tancítaro; pine-oak forest. Araro.--Lat. 19° 54', long. 100° 50', elev. 1830 m. A small village at the eastern end of the Lago de Cuitzeo lakebed; mesquite-grassland. Ario de Rosales.--Lat. 19° 12', long. 101° 42', elev. 1980 m. A town in the Cordillera Volcánica on the road from Pátzcuaro to La Huacana; mixed hardwoods and pine forest. Arteaga (formerly Carrizal).--Lat. 18° 28', long. 102° 25', elev. 850 m. A town in the eastern part of the Sierra de Coalcomán; transition between arid tropical scrub forest and oak forest. Atzimba.--Lat. 19° 39', long. 100° 47', elev. 2900 m. A national park in the Cordillera Volcánica, located between Ciudad Hidalgo and Morelia, 32 kilometers by road west-southwest of Ciudad Hidalgo; mixed pine and fir forest. Axolotl (Rancho).--Lat. 19° 47', long. 100° 38', elev. 2900 m. A settlement on the western slopes of Cerro San Andrés; pine, oak, and fir forest. Balsas (Río).--A large river having its headwaters in Tlaxcala, Puebla, and northwestern Oaxaca, flowing westward through an arid valley to the Pacific Ocean, and in its lower part forming the boundary between Michoacán and Guerrero. Barolosa (Cerro de).--Lat. 18° 52', long. 102° 57', elev. 2900-3050 m. Presumably the highest mountain in the Sierra de Coalcomán and located about 13 hours by mule east-northeast of Coalcomán; open pine-oak-fir forest and alder thickets. Barolosa (Rancho).--Lat. 18° 50', long. 103° 00', elev. 2320 m. A small ranch on the west-northwestern slope of Cerro de Barolosa, about 11 hours by mule east-northeast of Coalcomán; open pine-oak forest. Barranca Seca.--Lat. 19° 32', long. 102° 15', elev. 2100 m. A small village about 7 kilometers northwest of San Juan de Parangaricutiro; pine forest. Bejuco (Barranca de).--Lat. 18° 07', long. 102° 48', elev. 90 m. A barranca in the lower slopes of the Sierra de Coalcomán just west of the lower reaches of the Río Nexpa; tropical semi-deciduous forest. Buenavista (Tomatlán).--Lat. 19° 17', long. 102° 36', elev. 425 m. A village on the Río Masiaco in the Tepalcatepec Valley, 33 kilometers by road west-northwest of Apatzingán; open arid tropical scrub forest. Buena Vista.--Lat. 18° 40', long. 102° 09', elev. 600 m. A ranch on the northeastern slopes of the Sierra de Coalcomán; arid tropical scrub forest. Cachán (Río).--Lat. 18° 14', long. 103° 14'. A river formed by the affluence of the Río Coalcomán and the Río San José and flowing into the Pacific Ocean at a point indicated by the co-ordinates given above. Sometimes the name is applied to the lower part of the river as used here; other times the name is used for the entire length of the Río Coalcomán. Camichines.--Lat. 18° 47', long. 103° 05', elev. 1070 m. A ranch about 5 kilometers east-northeast of Coalcomán; transition between arid tropical scrub forest and oak forest. Camécuaro (Lago de).--Lat. 19° 55', long. 102° 13', elev. 1615 m. A small lake (depth to about 10 m.) drained by the Río Duero and located one kilometer north-northwest of Tangancícuaro; mesquite-grassland and some cypress and oak around the lake. Cancita (Río).--A tributary of the Río Tepalcatepec flowing southward from the southeastern slope of Cerro de Tancítaro. Cantiles (Los).--Lat. 19° 43', long. 100° 55', elev. 2160 m. A ranch 33 kilometers by road east of Morelia; pine forest. Capácuaro.--Lat. 19° 33', long. 102° 02', elev. 2070 m. A Tarascan village 18 kilometers by road north of Uruapan; pine forest. Capirio.--Lat. 18° 52', long. 102° 08', elev. 180 m. A village on the Río Tepalcatepec, 22 kilometers by road south of Nueva Italia; open arid tropical scrub forest and some gallery forest along the river. Carapan.--Lat. 19° 52', long. 102° 02', elev. 2070 m. A village on the northern edge of the Sierra de los Tarascos, 32 kilometers by road west of Zacapu; pine-oak forest at village and to the south; mesquite-grassland immediately to the north. Cerrito (El).--Lat. 18° 45', long. 103° 40', elev. 15 m. A ranch about 3 kilometers northeast of Coahuayana; tropical semi-deciduous forest. Chapala (Lago de).--A large lake on the Mexican Plateau at an elevation of 1525 m., partly in the state of Jalisco. It is drained by the Río Grande de Santiago, which flows northward and then westward into the Pacific Ocean. Immediately to the east of the lake are remnants of once extensive marshes. Charapendo.--Lat. 19° 15', long. 102° 04', elev. 975 m. A village 24 kilometers by road south of Uruapan near the upper limit of the arid tropical scrub forest in the Tepalcatepec Valley. Cherán.--Lat. 19° 42', long. 101° 57', elev. 2350 m. A Tarascan village 27 kilometers by road south-southeast of Carapan; pine forest. Chichihuas.--Lat. 18° 47', long. 103° 12', elev. 1200 m. A ranch about 6 kilometers west-southwest of Coalcomán; scrub oak forest. Chinapa.--Lat. 19° 22', long. 100° 51', elev. 930 m. A small village on the Río Chinapa, 43 kilometers south of El Temzcal on the road to Huetamo; arid tropical scrub forest. Chupio.--Lat. 19° 10', long. 101° 27', elev. 1080 m. A village 12 kilometers by road south of Tacámbaro; transition between arid tropical scrub forest and oak forest. Churumuco.--Lat. 18° 37', long. 101° 38', elev. 210 m. A small town in the Balsas Valley; arid tropical scrub forest. Ciénega (La).--Lat. 18° 28', long. 103° 18', elev. 900 m. A ranch about 3 hours by mule north of Coire; tropical semi-deciduous forest. Coahuayana.--Lat. 18° 44', long. 103° 31', elev. 15 m. A village on the coastal plain near the mouth of the Río Coahuayana; arid tropical scrub forest and tropical semi-deciduous forest. Coalcomán.--Lat. 18° 47', long. 103° 08', elev. 945 m. The largest town in the Sierra de Coalcomán and situated in a valley about 12 by 6 kilometers; arid tropical scrub forest on valley floor; oaks and some tropical semi-deciduous forest on surrounding slopes. Coalcomán (Río).--A river having its headwaters northeast of the town of Coalcomán and flowing southward to join with the Río San José to form the Río Cachán. Coalcomán (Sierra de).--A highland mass outlined by the Río Coahuayana and its tributaries on the west, the Río Tepalcatepec on the north, and the Río Balsas on the east, and the Pacific Ocean on the south. The axis of the sierra extends for about 200 kilometers in a west-northwest to east-southeast direction; the mountains are nearly 80 kilometers in breadth; the highest parts of the range are about 3000 meters above sea level. Cofradía.--Lat. 18° 56', long. 102° 17', elev. 215 m. A ranch about 17 kilometers southeast of Apatzingán; arid tropical scrub forest. Coire.--Lat. 18° 26', long. 103° 22', elev. 300 m. A village on the seaward foothills of the Sierra de Coalcomán on the Río Coire; tropical semi-deciduous forest. Cojumatlán.--Lat. 20° 07', long. 102° 51', elev. 1530 m. A village on the southeastern shore of Lago de Chapala; mesquite-grassland. Colola (Río).--A small river emptying into the Pacific Ocean between Maruata and Punto San Telmo. Conejos (Los).--Lat. 19° 22' long. 102° 07', elev. 1850 m. A village 6 kilometers west-southwest of Uruapan, and sometimes known as Nuevo San Juan; pine-oak forest. Copándaro.--Lat. 19° 54', long. 101° 12', elev. 1800 m. A village on the south edge of the Lago de Cuitzeo lakebed; mesquite-grassland. Copuyo (Capuyo or Copullo).--Lat. 18° 28', long. 100° 56', elev. 1200 m. A small village about 5 kilometers by road west of Paso Ancho; transition between arid tropical scrub forest and oak forest. Cordillera Volcánica.--A mountain range along the southern edge of the Mexican Plateau, roughly along the nineteenth parallel, and made up of many volcanos; the range extends from Volcán de Colima on the west to Cofre de Perote and Orizaba in Veracruz; several of the volcanos reach elevations of more than 4000 meters. Corralito (El).--Lat. 18° 52', long. 102° 38', elev. 270 m. A small village in the Tepalcatepec Valley, about 30 kilometers southwest of Apatzingán; arid tropical scrub forest. Corupu (Corupo).--Lat. 19° 28', long. 102° 19', elev. 2450 m. A village 29 kilometers northwest of Uruapan; pine forest. Cuatro Caminos.--Lat. 19° 00', long. 102° 05' elev. 335 m. A village 4 kilometers south of Nueva Italia; arid tropical scrub forest. Cuilala (Playa).--Lat. 18° 10', long. 103° 06', sea level. A sandy beach on the Pacific Ocean just east of La Higuerita. Cuitzeo.--Lat. 19° 58', long. 101° 09', 1800 m. A village on the north shore of the Lago de Cuitzeo lakebed; mesquite-grassland. Cuitzeo (Lago de).--A large lakebed on the Mexican Plateau at an elevation of 1800 m. In dry years there is little water in the lake, and most of the lakebed is dry; in very wet years the entire lakebed is flooded. The Río de Morelia flows into the lake, which has no outlet; surrounding vegetation is mesquite-grassland. Cuseño Station.--Lat. 19° 30', long. 102° 16', elev. 2200 m. A field station of the American Geological Society established in 1945 and demolished in 1953; located at the northern edge of the lava flow at Volcán Parícutin; remnants of pine forest. Diezmo (El).--Lat. 18° 26', long. 103° 19', elev. 850 m. A ranch about 8 kilometers north of Coire; tropical semi-deciduous forest. Dos Aguas.--Lat. 18° 45', long. 102° 55', elev. 2100 m. A lumber camp on the eastern slope of Cerro de Barolosa, located about 22 kilometers west-northwest of Aguililla; pine-oak forest and some fir forest in sheltered ravines. Duero (Río).--A small river having its headwaters near Tangancícuaro and flowing northwestward into the Río Lerma; source of irrigation water for surrounding agricultural area. Emiliano Zapata.--Lat. 18° 59', long. 102° 39' elev. 1600 m. A town 10 kilometers east of Jiquilpan; mesquite-grassland and irrigated fields. Erongaricuaro.--Lat. 19° 35', long. 101° 43', elev. 2150 m. A Tarascan village on the western shore of Lago de Pátzcuaro; pine forest. Espinal (El).--Lat. 18° 27', long. 102° 07', elev. 500 m. A ranch in the northern foothills of the Sierra de Coalcomán, 9 kilometers by road north-northeast of San Salvador; arid tropical scrub forest. Estopilas (Salitre de).--Lat. 18° 30', long. 103° 23', elev. 130 m. A small village about 10 kilometers east of Ostula; tropical semi-deciduous forest and arid tropical scrub forest. Garnica (Cerro).--Lat. 19° 43', long. 100° 48', elev. 3000 m. A mountain about 8 kilometers north of Pino Gordo; pine-oak-fir forest. Garnica (Puerto de).--Lat. 19° 42', long. 100° 51', elev. 2840 m. A mountain pass 46 kilometers by road west of Ciudad Hidalgo; pine and fir forest. Gregorio (San).--Lat. 19° 25', long. 101° 24', elev. 2200 m. A ranch about 16 kilometers southeast of Pátzcuaro; pine forest. Guayabo.--Lat. 18° 45', long. 102° 15', elev. 760 m. A village in the Sierra de Coalcomán about 32 kilometers north-northeast of Arteaga; upper limits of arid tropical scrub forest. Herradero (Barranca de).--Lat. 18° 17', long. 103° 08', elev. 200-250 m. A barranca south of San Pedro Naranjestila in the Sierra de Coalcomán; tropical semi-deciduous forest. Hidalgo (Ciudad).--Lat. 19° 32', long. 100° 34', elev. 2100 m. A town in the valley of the Río Tuxpan; mesquite-grassland and pine-oak forest. Higuerita (La).--Lat. 18° 12', long. 103° 06', sea level. A place name on the Pacific coast; sandy beach and arid tropical scrub forest. Higuertas (Las).--Lat. 18° 39', long. 103° 17', elev. 1600 m. A ranch about 7 hours by mule southwest of Coalcomán; pine-oak forest. Hondo (Puerto).--Lat. 19° 25', long. 100° 13', elev. 2750 m. A pass in the mountains, 14 kilometers by road east of Zitácuaro (just west of Macho de Agua); pine, oak, and fir forest. Huancana (La).--Lat. 18° 58', long. 101° 50', elev. 550 m. A village in the Balsas Basin; arid tropical scrub forest. Huahua (La).--Lat. 18° 12', long. 103° 00', sea level. A small village on the Pacific coast; arid tropical scrub forest and gallery forest along the Arroyo de Huahua. Huetamo.--Lat. 18° 38', long. 100° 53', elev. 300 m. A town in the Balsas Valley; arid tropical scrub forest. Huingo.--Lat. 19° 55', long. 100° 50', elev. 1800 m. A village on the eastern edge of the Lago de Cuitzeo lakebed; mesquite-grassland. Jacona.--Lat. 19° 57', long. 102° 18', elev. 1600 m. A small town, 4.3 kilometers by road southwest of Zamora; mesquite-grassland. Jaramillo.--Lat. 19° 20', long. 102° 02', elev. 1500 m. A ranch 9 kilometers by road south of Uruapan; pine-oak forest. Jazmin.--Lat. 18° 52', long. 101° 58', elev. 275 m. A village in the Tepalcatepec Valley, 32 kilometers by road southeast of Cuatro Caminos; open arid tropical scrub forest. Jeráhuaro.--Lat. 19° 52', long. 100° 35', elev. 2600 m. A town in the northern part of the state and located east of Lago de Cuitzeo; pine-oak forest. Jiquilpan.--Lat. 19° 59', long. 102° 43', elev. 1570 m. A town just southeast of Lago de Chapala; mesquite-grassland. Jorullo (Volcán).--Lat 19° 00', long. 101° 45', elev. 1300 m. (crest). A cinder and lava cone rising from the foothills of the Cordillera Volcánica; arid tropical scrub forest on lower slopes and pine-oak forest on top. Jungapeo.--Lat. 19° 26', long. 100° 29', elev. 1430 m. A village in the valley of the Río Tuxpan, about 13 kilometers south of Tuxpan on the southern slopes of the Mexican Plateau; tropical semi-deciduous forest and pine-oak forest. Lengua de Vaca (Puerto de).--Lat. 19° 26', long. 100° 13', elev. 2900 m. A pass in the mountains at the Michoacán-Mexico border through which passes the Mexico City-Morelia highway; pine and fir forest. Lerma (Río).--A river originating in the state of México and flowing westward, and forming the northern boundary of the state of Michoacán, to Lago de Chapala. Lima (San Juan de).--Lat. 18° 29', long. 102° 42', sea level. A ranch on the Pacific coast; arid tropical scrub forest and tropical semi-deciduous forest. Lima (Punta San Juan de).--Lat. 18° 38', long. 102° 43', sea level. A rocky promontory jutting into the Pacific Ocean just southwest of San Juan de Lima; arid tropical scrub forest. Limoncito.--Lat. 18° 45', long. 102° 43', elev. 730 m. A ranch 10 kilometers north of Aguililla; arid tropical scrub forest; tropical semi-deciduous gallery forest along the nearby Río Tepecuate. Lombardia.--Lat. 19° 08', long. 102° 02', elev. 640 m. A town in the Tepalcatepec Valley, 38 kilometers by road south of Uruapan; arid tropical scrub forest. Lleguas (Acuaro de las).--Lat. 18° 48', long. 102° 52', elev. 2320 m. A place name for a stream and meadow (Llano de la Llegua) surrounded by pine-oak forest, located about 10 hours by mule east of Coalcomán. Macho de Agua.--Lat. 19° 25', long. 100° 15', elev. 2850 m. A ranch just west of Puerto de Lengua de Vaca and 16 kilometers by road east of Zitácuaro; mixed oak, pine, and fir forest. Maquili.--Lat. 18° 36', long. 103° 32', elev. 120 m. A village on the Río Aquila about 3 kilometers south-southwest of Aguila; tropical semi-deciduous forest. Maravatio.--Lat. 19° 53', long. 100° 27', elev. 2010 m. A town in the Río Lerma Valley; irrigated fields on flats and pine-oak forest on slopes. Marquez (Río).--A tributary to the Río Tepalcatepec, flowing through a deep gorge (Barranca del Marquez) between Lombardia and Nueva Italia. The stream originates from springs near Uruapan, where the stream is known as the Río Cupatitzio. Maruata.--Lat. 18° 17', long. 103° 20', sea level. Place name for a Nineteenth Century port of little importance near the mouth of the Río Coire; sandy beach, fresh-water lagoon, and arid tropical scrub forest. Mexcala (Laguna).--Lat. 18° 29', long. 103° 41', sea level. A brackish lagoon surrounded by mangroves, located just southwest of El Ticuiz. Mil Cumbres.--Lat. 19° 39', long. 100° 47', elev. 2800 m. A name for a look-out on the México-Morelia highway in Atzimba National Park, about 32 kilometers by road west-southwest of Ciudad Hidalgo; pine and fir forest. Mira (La).--Lat. 18° 05', long. 102° 20', elev. 20 m. A small village about 5 kilometers north-northeast of Playa Azul; arid tropical scrub forest. Morelia.--Lat. 19° 43', long. 101° 10', elev. 1900 m. Capital of and largest city in Michoacán; mesquite-grassland on flats and pine-oak forest on surrounding hills. Morelia (Río de).--A small, intermittent stream originating in the mountains south of Morelia and emptying into Lago de Cuitzeo. Motín del Oro.--Lat. 18° 14', long. 103° 48', sea level. A ranch on the Pacific coast; arid tropical scrub forest. Motín (Río).--Lat. 18° 13', long. 103° 48' (mouth). A small river flowing from the Sierra de Coalcomán into the Pacific Ocean. Nahuatzen (Nauhuatzin).--Lat. 19° 42', long. 101° 50', elev. 2450 m. A Tarascan village in the mountains west of Lago de Pátzcuaro; pine forest. Nexpa (Río).--Lat. 18° 05', long. 102° 47' (mouth). A large river draining the central part of the Sierra de Coalcomán, originating near Aguililla, and flowing into the Pacific Ocean. Nogueleras.--Lat. 18° 34', long. 103° 17', elev. 1600 m. A ranch about 10 hours by mule south-southwest of Coalcomán; oak forest. Nueva Italia.--Lat. 19° 02', long. 102° 07', elev. 380 m. A town in the Tepalcatepec Valley, 59 kilometers by road south of Uruapan; arid tropical scrub forest. Nuevo (Rancho).--Lat. 18° 26', long. 102° 07', elev. 520 m. A ranch 7 kilometers by road north-northeast of San Salvador in the northern foothills of the Sierra de Coalcomán; arid tropical scrub forest. Ocorla.--Lat. 18° 38', long. 103° 07', elev. 885 m. A ranch about 6 hours by mule south-southeast of Coalcomán; scrubby oak forest. Opopeo.--Lat. 19° 24', long. 101° 37', elev. 2800 m. A village 16 kilometers south of Pátzcuaro; pine and fir forest. Orilla (La).--Lat. 18° 00', long. 102° 12', elev. 10 m. The site of a former hacienda of the same name near the mouth of the Río Balsas; arid tropical scrub forest. Oropeo.--Lat. 18° 52', long. 101° 48', elev. 300 m. A village in the Tepalcatepec Valley about 13 kilometers south of La Huacana; arid tropical scrub forest. Ostula.--Lat. 18° 30', long. 103° 28', elev. 120 m. A village in the seaward foothills of the Sierra de Coalcomán, located on the Río Ostula about 16 kilometers east-southeast of La Placita; arid tropical scrub forest and scattered tropical semi-deciduous forest. Ozumatlán (Sierra de).--A range in the Cordillera Volcánica extending east-northeast from a point south of Morelia to Queréndaro and reaching elevations in excess of 2600 m. Palma (La).--Lat. 20° 09', long. 102° 46', elev. 1525 m. A village on the southeastern shore of Lago de Chapala; lake-shore marshes and mesquite-grassland. Paracho.--Lat. 19° 39', long. 102° 02', elev. 2375 m. A Tarascan village in the Cordillera Volcánica, located 35 kilometers by road north of Uruapan; pine forest. Parangaricutiro (San Juan de).--Lat. 19° 30', long. 102° 15', elev. 2200 m. A former Tarascan village that was destroyed by the eruption of Volcán Parícutin; lava and volcanic ash amidst open pine forest. Parícutin (Volcán).--Lat. 19° 30', long. 102° 16', elev. 2200 m. at base and 2700 m. at summit. A volcano born in February, 1943; it ceased to be active in December, 1951, and is located at the north-northeastern base of Cerro de Tancítaro; volcanic ash and lava amidst open pine forest. Paso Ancho.--Lat. 19° 28', long. 100° 52', elev. 1100 m. A small village 30 kilometers south of El Temazcal on the road to Huetamo; arid tropical scrub forest. Patamba (Sierra).--Lat. 19° 45', long. 102° 21', elev. 3700 m. at summit. A mountain, the summit of which is about 22 kilometers southwest of Tangancícuaro; pine forest from 2000 to 2600 m.; fir forest above 2600 m. Pátzcuaro.--Lat. 19° 30', long. 101° 36', elev. 2200 m. A town near the southeastern shore of Lago de Pátzcuaro; pine forest. Pátzcuaro (Lago de).--A large lake on the southwestern part of the Mexican Plateau at an elevation of 2165 m. It has no outlet. The lake is surrounded by mountains supporting pine and pine-oak forest. Along the southern and eastern shores of the lake are small marshes. Peñas (Las).--Lat. 18° 03', long. 102° 38', sea level. A small village on the Pacific coast; arid tropical scrub forest. Pichi (Estero).--Lat. 18° 01', long. 102° 24', sea level. A brackish lagoon surrounded by mangroves and coconut groves, located just east of Playa Azul. Pino Gordo.--Lat. 19° 42', long. 100° 45', elev. 2600 m. A ranch 37 kilometers by road west of Ciudad Hidalgo; pine-oak forest. Placita (La).--Lat. 18° 32', long. 103° 37', elev. 20 m. A village on the coastal lowlands, located on the Río Aquila; arid tropical scrub forest; tropical semi-deciduous forest along the river. Playa (La).--Lat. 18° 57', long. 102° 33', elev. 800 m. A small village on the western edge of the lava flow of Volcán Jorullo; arid tropical scrub forest and some tropical semi-deciduous forest in ravines. Playa Azul.--Lat. 18° 01', long. 102° 25', sea level. A village on the Pacific coast near the mouth of the Río Carrizal; arid tropical scrub forest; coconut plantations; mangrove-lined lagoons. Pómaro.--Lat. 18° 18', long. 103° 17', elev. 300 m. An Indian village in the southern foothills of the Sierra de Coalcomán, located about 3 hours by mule north-northeast of Maruata; tropical semi-deciduous forest. Pozos (Los).--Lat. 18° 30', long. 103° 17', elev. 300 m. A ranch located about 5 hours by mule north of Coire; tropical semi-deciduous forest. Queréndaro.--Lat. 19° 48', long. 100° 53', elev. 1900 m. A town on the Mexican Plateau south of Lago de Cuitzeo; mesquite-grassland. Quiroga.--Lat. 19° 42', long. 101° 30', elev. 2200 m. A Tarascan town on the north edge of Lago de Pátzcuaro; mesquite-grassland and pine-oak forest. Reyes (Los).--Lat. 19° 35', long. 102° 28', elev. 1500 m. A town in western Michoacán, 50 kilometers south-southwest of Zamora; mesquite-grassland, oak and pine forest. Sabino (El).--Lat. 19° 14', long. 102° 03', elev. 1050 m. A hacienda about 24 kilometers south of Uruapan; arid tropical scrub forest, many streams, rice fields. Sahuayo.--Lat. 20° 05', long. 102° 43', elev. 1550 m. A town just south of the eastern end of Lago de Chapala; mesquite-grassland. Salada (La).--Lat. 19° 07', long. 102° 00', elev. 580 m. A ranch southwest of Lombardia; arid tropical scrub forest. Salto (Arroyo El).--Lat. 18° 45', long. 103° 04', elev. 1370 m. A valley of the Río Flores about 3 hours by mule east-southeast of Coalcomán; pine-oak forest. San Andrés (Cerro).--Lat. 19° 48', long. 100° 35', elev. 3950 m. at summit. A mountain, the summit of which is about 16 kilometers north-northwest of Ciudad Hidalgo; oak forest to 2500 m. and pine and fir forest above 2500 m. San José (de la Cumbre).--Lat. 19° 41', long. 100° 50', elev. 2750 m. A ranch 51 kilometers by road east of Morelia; pine and fir forest. San José (de la Montaña).--Lat. 18° 25', long. 103° 06', elev. 750 m. A village sometimes called La Guitarra, located 14 hours by mule south-southeast of Coalcomán; tropical semi-deciduous forest. San Pedro Naranjestila.--Lat. 18° 17', long. 103° 06', elev. 500 m. An Indian village in the southern foothills of the Sierra de Coalcomán; tropical semi-deciduous forest. San Salvador.--Lat. 18° 25', long. 102° 08', elev. 700 m. A small village in the Sierra de Coalcomán, 37 kilometers by road northeast of Arteaga; arid tropical scrub forest. San Telmo (Ojos de Agua de).--Lat. 18° 37', long. 103° 42', sea level. A small settlement at the base of Punto San Juan de Lima; tropical semi-deciduous forest and groves of oil palms. San Telmo (Punta).--Lat. 18° 18', long. 103° 29', sea level. A rocky promontory jutting into the Pacific Ocean, on which there is a lighthouse (El Faro); arid tropical scrub forest. Santa Ana.--Lat. 18° 27', long. 102° 06', elev. 600 m. A ranch about 4 kilometers by road northeast of San Salvador; arid tropical scrub forest. Tacámbaro.--Lat. 19° 05', long. 101° 22', elev. 1820 m. A town in the Cordillera Volcánica; pine forest. Tacícuaro.--Lat. 19° 38', long. 101° 18', elev. 2000 m. A village 21 kilometers east-southeast of Quiroga; mesquite-grassland and scrubby oak forest. Tafetan.--Lat. 19° 43', long. 100° 52', elev. 1000 m. A village 40 kilometers by road south of El Temazcal; arid tropical scrub forest. Tancítaro.--Lat. 19° 20', long. 102° 22', elev. 1850 m. A small town on the southern slope of Cerro de Tancítaro; pine-oak forest. Tancítaro (Cerro de).--Lat. 19° 25', long. 102° 18', elev. 3870 m. at summit. An old volcano in the Cordillera Volcánica; the southern slope drops into the Tepalcatepec Valley; the summit is about 30 kilometers west of Uruapan; pine and oak forest on lower slopes replaced by pine or fir forest above. Tangamandapio.--Lat. 19° 56', long. 102° 25', elev. 1700 m. A small town on the Mexican Plateau between Jiquilpan and Zamora; mesquite-grassland and irrigated fields. Tangancícuaro.--Lat. 19° 52', long. 102° 13', elev. 1770 m. A town 12 kilometers by road southeast of Zamora; mesquite-grassland and irrigated fields. Tarascos (Sierra de los).--A name applied to that part of the Cordillera Volcánica extending eastward from Cerro de Tancítaro and Sierra Patamba to Pátzcuaro. Tarécuaro.--Lat. 19° 53', long. 102° 29', elev. 1700 m. A village on the Mexican Plateau, 26 kilometers southwest of Zamora; mesquite-grassland and pine-oak forest. Tecatas (Las).--Lat. 18° 36', long. 103° 17', elev. 1950 m. A ranch located about 10 hours by mule south-southwest of Coalcomán; oak forest. Temazcal (El).--Lat. 19° 40', long. 100° 56', elev. 2200 m. A road junction, 29 kilometers east of Morelia; here the road to Huetamo leads south from the Mexico City-Morelia highway; pine forest. Tepalcatepec.--Lat. 19° 10', long. 102° 50', elev. 570 m. A village in the upper Tepalcatepec Valley; arid tropical scrub forest. Tepalcatepec (Río).--A large river having its headwaters in southeastern Jalisco and flowing through a broad valley, which separates the Cordillera Volcánica from the Sierra de Coalcomán, to the Río Balsas. Ticuiz (El).--Lat. 18° 40', long. 103° 40', elev. 10 m. A village on the coastal plain about 11 kilometers south of Coahuayana; arid tropical scrub forest and tropical semi-deciduous forest. Tinguidín.--Lat. 19° 45', long. 102° 28', elev. 1800 m. A small town, 17 kilometers north of Los Reyes; pine-oak forest. Tizupan (Río).--Lat. 18° 09', long. 102° 55' (mouth). A small river flowing southward from the Sierra de Coalcomán to the Pacific Ocean. Tlalpujahua.--Lat. 19° 48', long. 100° 10', elev. 2600 m. A mining town in the northeastern part of the state; pine and fir forest. Tumbiscatio.--Lat. 18° 32', long. 102° 20', elev. 900 m. A town in the Sierra de Coalcomán; arid tropical scrub forest. Tupátaro.--Lat. 19° 53', long. 100° 15', elev. 2050 m. A village in the northeastern corner of the state, 13 kilometers northwest of Tlalpujahua; oak forest. Tuxpan.--Lat. 19° 35', long. 100° 27', elev. 1850 m. A town in a basin nearly surrounded by mountains and near the headwaters of the Río Tuxpan, 19 kilometers by road east-southeast of Ciudad Hidalgo; arid mesquite-grassland and irrigated fields. Tuxpan (Río).--A river draining the mountains in the eastern part of the state and flowing southward into the Río Balsas. Tzararacua (Cascada).--Lat. 19° 18', long. 102° 02', 1430 m. A waterfalls of the Río Cupatitzio, 10.5 kilometers by road south of Uruapan; oak forest with scattered pines. Tzintzuntzan.--Lat. 19° 38', long. 101° 35', elev. 2170 m. A village at the site of the seat of the ancient Tarascan empire on the eastern shore of Lago de Pátzcuaro; grasslands and marshes. Tzitzio.--Lat. 19° 35', long. 100° 55', elev. 1630 m. A village 16 kilometers by road south of El Temazcal; pine-oak and arid tropical scrub forest. Ucareo (Serranía de).--A part of the Cordillera Volcánica, including Cerro San Andrés. Undameo.--Lat. 19° 34', long. 101° 17', elev. 2000 m. A village 20 kilometers west-southwest of Morelia; mesquite-grassland. Uruapan.--Lat. 19° 25', long. 102° 02', elev. 1630 m. A large town on the southern slopes of the Cordillera Volcánica; pine-oak forest. Zacapu.--Lat. 19° 48', long. 101° 47', elev. 2000 m. A town on the Mexican Plateau; mesquite-grassland. Zamora.--Lat. 19° 59', long. 102° 17', elev. 1570 m. A large town on the Mexican Plateau; mesquite-grassland. Zicuiran.--Lat. 18° 53', long. 101° 55', elev. 190 m. A small village 23 kilometers east-southeast of Cuatro Caminos; arid tropical scrub forest. Zinapécuaro.--Lat. 19° 52', long. 100° 49', elev. 1900 m. A town near the southeastern end of Lago de Cuitzeo; mesquite-grassland and pine-oak forest. Ziracuaretiro.--Lat. 19° 25', long. 101° 52', elev. 1230 m. A village 19 kilometers by road east of Uruapan; transition between pine-oak forest and arid tropical scrub forest. Zirimícuaro.--Lat. 19° 24', long. 101° 56', elev. 1300 m. A hacienda 13 kilometers by road east of Uruapan; pine-oak forest and fields of sugar cane. Zitácuaro.--Lat. 19° 25', long. 100° 21', elev. 2100 m. A town in the highlands of eastern Michoacán; pine-oak forest. Zurumbeneo.--Lat. 19° 43', long. 101° 02', elev. 2100 m. A ranch 19 kilometers by road east of Morelia; scrubby oak forest. SUMMARY The preceding analysis of the amphibians and reptiles of the state of Michoacán shows that the herpetofauna is composed of 176 species and subspecies definitely recorded from the state, plus ten others that probably occur there. Ten species are reported for the first time from Michoacán: _Pseudoeurycea robertsi_, _Leptodactylus occidentalis_, _Microbatrachylus pygmaeus_, _Pternohyla fodiens_, _Hypopachus caprimimus_, _Phyllodactylus homolepidurus_, _Anolis dunni_, _Sceloporus bulleri_, _Sceloporus heterolepis,_ and _Geagras redimitus_. Five species that have been reported previously from Michoacán are based on specimens having unreliable locality data or on misidentifications; therefore, the following species are not considered to be a part of the herpetofauna of Michoacán: _Caiman crocodilus fuscus_, _Urosaurus irregularis_, _Geophis nasalis_, _Tropidodipsas fasciata guerreroensis_, and _Micrurus fitzingeri fitzingeri_. Systematic studies based at least in part on specimens from Michoacán have resulted in a redefinition of nine species and subspecies: _Bufo marmoreus_, _Bufo perplexus_, _Anolis nebulosus_, _Anolis nebuloides_, _Sceloporus bulleri_, _Sceloporus heterolepis_, _Sceloporus melanorhinus calligaster_, _Hypsiglena torquata torquata_, and _Hypsiglena torquata ochrorhyncha_. Nine species that previously have been recognized as valid have been placed in synonymy. These are: _Bufo horribilis_ Wiegmann, 1833, and _Bufo angustipes_ Smith and Taylor, 1945, as synonyms of _Bufo marinus_ (Linnaeus), 1758. _Microbatrachylus albolabris_ Taylor, 1940, _Microbatrachylus minimus_ Taylor, 1940, and _Microbatrachylus imitator_ Taylor, 1942, as synonyms of _Microbatrachylus pygmaeus_ (Taylor), 1937. _Phrynohyas corasterias_ Shannon and Humphrey, 1957, as a synonym of _Phrynohyas inflata_ (Taylor), 1944. _Hyla microeximia_ Maslin, 1957, as a synonym of _Hyla eximia_ Baird, 1854. _Hylella azteca_ Taylor, 1943, as a synonym of _Hyla smaragdina_ Taylor, 1940. _Loxocemus sumichrasti_ Bocourt, 1876, as a synonym of _Loxocemus bicolor_ Cope, 1861. _Eleutherodactylus vocalis_ Taylor, 1940, is considered to be a subspecies of _Eleutherodactylus rugulosus_. The populations of _Thamnophis dorsalis_ in the Tepalcatepec Valley are shown to be distinct from those inhabiting the highlands of the state; _Thamnophis dorsalis postremus_ Smith, 1942, is revived for the population in the Tepalcatepec Valley. Descriptions are given of the tadpoles of _Bufo occidentalis_ and _Hyla bistincta_. LITERATURE CITED ANDERSON, J. D. 1960. _Storeria storerioides_ in western Mexico. Herpetologica, 16:63-6, March 31. BOGERT, C. M., and OLIVER, J. A. 1945. A preliminary analysis of the herpetofauna of Sonora. Bull. Amer. Mus. Nat. Hist., 83:297-426, March 30. BOULENGER, G. A. 1885. Catalogue of the lizards in the British Museum, vol. II. London, xiii + 497 pp., November 15. 1894. Catalogue of the snakes in the British Museum, vol. II, London, xi + 382 pp., September 23. CONANT, R. 1953. Three new water snakes of the genus _Natrix_ from Mexico. Nat. Hist. Misc., 126:1-9, September 15. CONTRERAS ARIAS, A. 1942. Mapa de las provincias climatologicas de la República Méxicana. Dir. Meteoro, Hidro. Inst. Geog. México, xxvii + 54 pp. COPE, E. D. 1861. Contributions to the ophidiology of Lower California, Mexico, and Central America. Proc. Acad. Nat. Sci. Philadelphia, 13:292-306, December 28. 1887. Catalogue of batrachians and reptiles of Central America and Mexico. Bull. U. S. Natl. Mus., 32:1-98. DAVIS, W. B. 1954. Three new anoles from Mexico. Herpetologica, 10:1-6, April 20. DAVIS, W. B., and DIXON, J. R. 1957. Notes on Mexican snakes (Ophidia). Southwest. Nat., 2:19-27, January. DAVIS, W. B., and SMITH, H. M. 1953. Lizards and turtles of the Mexican state of Morelos. Herpetologica. 9:100-108, July 22. DIXON, J. R. 1957. Geographic variation and distribution of the genus _Tomodactylus_ in Mexico. Texas Jour. Sci., 9:379-409, December. 1960. Two new geckos, genus _Phyllodactylus_ (Reptilia: Sauria), from Michoacán, Mexico. Southwest. Nat., 5:37-42, April 15. DOWLING, H. G. 1960. A taxonomic study of the ratsnakes, genus _Elaphe_ Fitzinger. VII. The _triaspis_ section, Zoologica, 45:53-80, August 15. DUELLMAN, W. E. 1954a. The salamander _Plethodon richmondi_ in southwestern Ohio. Copeia, 1950 (1):40-45, February 19. 1954b. The amphibians and reptiles of Jorullo Volcano, Michoacan, Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 560:1-24, October 22. 1955. A new whiptail lizard, genus _Cnemidorphorus_, from Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 574:1-7, December 23. 1956a. The frogs of the hylid genus _Phrynohyas_ Fitzinger, 1843. Misc. Publ. Mus. Zool. Univ. Michigan, 96:1-47, February 21. 1956b. A new snake of the genus _Leptotyphlops_ from Michoacán, México. Copeia, 1956 (2):93-94, May 29. 1957a. Sexual dimorphism in the hylid frog _Agalychnis dacnicolor_ Cope, and the status of _Agalychnis alcorni_ Taylor. Herpetologica, 13:29-30, March 30. 1957b. Notes on snakes from the Mexican state of Sinaloa. Herpetologica, 13:237-240, October 31. 1958a. A monographic study of the colubrid snake genus _Leptodeira_. Bull. Amer. Mus. Nat. Hist., 114:1-152, February 24. 1958b. Comments on the type locality and geographic distribution of _Urosaurus gadowi_. Copeia, 1958 (1):48-49, February 21. 1958c. A preliminary analysis of the herpetofauna of Colima, Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 589:1-22, March 21. 1959. Two new snakes, genus _Geophis_, from Michoacan, Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 605:1-9, May 29. 1960a. A new subspecies of lizard, Cnemidophorus sacki, from Michoacán, México. Univ. Kansas Publ. Mus. Nat. Hist., 10:587-598, May 2. 1960b. A taxonomic study of the Middle American snake Pituophis deppei, Univ. Kansas Publ. Mus. Nat. Hist., 10:599-610, May 2. 1960c. Variation, distribution, and ecology of the Mexican teiid lizard _Cnemidophorus calidipes_. Copeia, 1960(2):97-101, June 29. 1960d. A distributional study of the amphibians of the Isthmus of Tehuantepec, México. Univ. Kansas Publ. Mus. Nat. Hist., 13:19-72, August 16. DUELLMAN, W. E., and DIXON, J. R. 1959. A new frog of the genus _Tomodactylus_ from Michoacán, Mexico. Texas Jour. Sci., 11:78-82, March. DUELLMAN, W. E., and DUELLMAN, A. S. 1959. Notes on the variation, distribution, and ecology of the iguanid lizard _Enyaliosaurus clarki_. Occ. Pap. Mus. Zool. Univ. Michigan, 598:1-10, February 16. DUELLMAN, W. E., and WELLMAN, J. 1960. A systematic study of the lizards of the _deppei_ group (Genus _Cnemidophorus_) in Mexico and Guatemala. Misc. Publ. Mus. Zool. Univ. Michigan, 111:1-80, February 10. DUGÈS, A. 1884. Dos reptiles de Mexico. La Naturaleza, 6:359-362. 1891. _Eumeces altamirani_ A. Dug. La Naturaleza, ser. 2, 1:485-486. 1896. Reptiles y batracios de los E. U. Mexicanos. La Naturaleza, ser. 2, 2:479-485. DUMÉRIL, A. M., and BOCOURT, F. 1870-1909. Mission scientifique au Mexique et dans l'Amerique Centrale, Recherches zoologiques. Études sur les reptiles. Paris, xiv + 1012 pp. FISCHER, J. G. 1882. Herpetologische Bemerkengen vorzugsweise über Stücke der Sammlung des Naturhistorischen Museum in Bremen. Abhand. Naturwiss. Ver. Bremen, 7:225-238. 1883. Beschreibungen neuer Reptilien. Akad. Gymnas. Hamburg, 1883:1-16. FITCH, H. S., and MILSTEAD, W. W. 1961. An older name for _Thamnophis cyrtopsis_ (Kennicott). Copeia, no. 1:112, March 17, 1961. FUNKHOUSER, A. 1957. A review of the Neotropical tree-frogs of the genus _Phyllomedusa_. Occ. Pap. Nat. Hist. Mus. Stanford Univ., 5:1-90, April 1. GADOW, H. 1905. Distribution of Mexican amphibians and reptiles. Proc. Zool. Soc. London, 1905:191-244, October 7. 1930. Jorullo. Cambridge Univ. Press, xviii + 100 pp. GLOYD, H. K. 1948. Description of a neglected subspecies of rattlesnake from Mexico. Nat. Hist. Misc., 17:1-4, April 23. GOIN, C. J. 1950. Color pattern inheritance in some frogs of the genus _Eleutherodactylus_. Bull. Chicago Acad. Sci., 9:1-15, March 3. 1954. Remarks on evolution of color pattern in the _gossei_ group of the frog genus _Eleutherodactylus_. Ann. Carnegie Mus., 33:185-195, June 4. GOLDMAN, E. A. 1951. Biological investigations in Mexico. Smithsonian Misc. Coll., 115, xii + 476 pp., July 31. GUZMÁN-RIVAS, P. 1957. Rainfall analysis for some stations in southwest Mexico. _In_ Brand, Coastal study of southwest Mexico, Part I. Univ. Texas, Austin, xii + 140 pp., June 15. HOROWITZ, S. B. 1955. An arrangement of the subspecies of the horned toad, _Phrynosoma orbiculare_ (Iguanidae). Amer. Midl. Nat., 54:209-218, July. KLAUBER, L. M. 1945. The geckos of the genus Coleonyx with descriptions of new subspecies. Trans. San Diego Soc. Nat. Hist., 10:133-216, March 9. 1952. Taxonomic studies of the rattlesnakes of Mainland Mexico. Bull. Zool. Soc. San Diego, 26:1-143, August 8. LANGEBARTEL, D. A. 1959. A new lizard (_Sceloporus_) from the Sierra Madre Occidental of Mexico. Herpetologica, 15:25-27, February 25. MALDONADO-KOERDELL, M. 1948. Los colecciones de anfibios del Museo Alfredo Dugès en la Universidad de Guanajuato, I--Urodelos. Mem. Revist. Acad. Nac. Cien., 56:185-226. MARTIN, P. S. 1958. A biogeography of reptiles and amphibians in the Gómez Farías Region, Tamaulipas, Mexico. Misc. Publ. Mus. Zool. Univ. Michigan, 101:1-102, April 15. MASLIN, T. P. 1957. _Hyla microeximia_ sp. n., Hylidae, Amphibia, from Jalisco, Mexico. Herpetologica, 13:81-86, July 10. MILSTEAD, W. W. 1953. Geographic variation in the garter snake, _Thamnophis cyrtopsis_. Texas Jour. Sci., 5:348-379, September. MOSIMANN, J. E. 1956. Variation and relative growth in the plastral scutes of the turtle _Kinosternon integrum_ LeConte. Misc. Publ. Mus. Zool. Univ. Michigan, 97:1-43, November 7. MOSIMANN, J. E., and RABB, G. B. 1953. A new subspecies of the turtle _Geoemyda rubida_ (Cope) from western Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 548:1-7, November 9. OLIVER, J. A. 1937. Notes on a collection of amphibians and reptiles from the state of Colima, Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 360:1-28, November 20. ORTON, G. 1943. The tadpole of _Rhinophrynus dorsalis_. Occ. Pap. Mus. Zool. Univ. Michigan, 472:1-8, May 18. PETERS, J. A. 1954. The amphibians and reptiles of the coast and coastal sierra of Michoacán, Mexico. Occ. Pap. Mus. Zool. Univ. Michigan, 554:1-37, June 23. 1955. Notes on the frog genus _Diaglena_ Cope. Nat. Hist. Misc., 143:1-8, March 28. 1957. The eggs (turtle) and I. Biologist, 39:21-4. RABB, G. B. 1958. On certain Mexican salamanders of the plethodontid genus _Chiropterotriton_. Occ. Pap. Mus. Zool. Univ. Michigan, 587:1-37, June 6. RABB, G. B., and MOSIMANN, J. E. 1955. The tadpole of _Hyla robertsorum_ with comments on the affinities of the species. Occ. Pap. Mus. Zool. Univ. Michigan, 563:1-9, March 29. REEVE, W. L. 1952. Taxonomy and distribution of the horned lizards genus _Phrynosoma_. Univ. Kansas Sci. Bull., 34 (pt. 2):817-960, February 15. SCHMIDT, K. P., and SHANNON, F. A. 1947. Notes on amphibians and reptiles of Michoacán, Mexico. Fieldiana, zool., 31:63-85, February 20. SHANNON, F. A., and HUMPHREY, F. L. 1957. A new species of _Phrynohyas_ from Nayarit. Herpetologica, 13:15-18, March 30. 1958. A discussion of the polytypic species, _Hypopachus oxyrrhinus_, with a description of a new subspecies. Herpetologica, 14:85-95, July 23. SMITH, H. M. 1938. The lizards of the _torquatus_ group of the genus _Sceloporus_ Wiegmann, 1828. Univ. Kansas Sci. Bull., 24:539-693, February 16. 1939. The Mexican and Central American lizards of the genus _Sceloporus_. Zool. ser., Field Mus. Nat. Hist., 26:1-397, July 27. 1941a. A review of the subspecies of the indigo snake (_Drymarchon corais_). Jour. Washington Acad. Sci., 31:466-481, November 11. 1941b. Notes on the snake genus _Trimorphodon_. Proc. U. S. Natl. Mus., 91:149-168, November 10. 1942a. Mexican Herpetological Miscellany. Proc. U. S. Natl. Mus., 92:349-395, November 5. 1942b. The synonymy of the garter snakes (_Thamnophis_), with notes on Mexican and Central American species. Zoologica, 27:97-123, October 23. 1942c. Remarks on the Mexican king snakes of the triangulum group. Proc. Rochester Acad. Sci., 8:196-207, September 10. 1942d. Descriptions of new species and subspecies of Mexican snakes of the genus _Rhadinaea_. Proc. Biol. Soc. Washington, 55:185-192, December 31. 1943. Summary of the collections of snakes and crocodilians made in Mexico under the Walter Rathbone Bacon Traveling Scholarship. Proc. U. S. Natl. Mus., 93:393-504, October 29. 1951. The identity of the ophidian name _Coluber eques_ Reuss. Copeia, 1951 (2):138-140, June 8. SMITH, H. M., and LAUFE, L. E. 1945. Notes on a herpetological collection from Oaxaca. Herpetologica, 3:1-13, November 21. SMITH, H. M., and TAYLOR, E. H. 1945. An annotated checklist and key to the snakes of Mexico. Bull. U. S. Natl. Mus., 187:iv + 239 pp., October 5. 1948. An annotated checklist and key to the Amphibia of Mexico. Bull. U. S. Natl. Mus., 194: iv + 118 pp., June 17. 1950a. Type localities of Mexican reptiles and amphibians. Univ. Kansas Sci. Bull., 33, pt. 2:313-380, March 20. 1950b. An annotated checklist and key to the reptiles of Mexico exclusive of the snakes. Bull. U. S. Natl. Mus., 199:v + 253, October 26. SMITH, P. W., and DARLING, D. M. 1952. Results of a herpetological collection from eastern central Mexico. Herpetologica, 8:81-86, November 1. STICKEL, W. H. 1943. The Mexican snakes of the genera _Sonora_ and _Chionactis_, with notes on the status of other colubrid genera. Proc. Biol. Soc. Washington, 56:109-128, October 19. STORM, M. 1939. Hoofways into hot country. Bland Bros., Mexico City, 521 pp. STUART, L. C. 1943. Comments on the herpetofauna of the Sierra de los Cuchumatanes of Guatemala. Occ. Pap. Mus. Zool. Univ. Michigan, 471:1-28, May 17. TAMAYO, J. L. 1949. Geografía General de Mexico. I--Geografía Fisica. Mexico City, viii + 628 pp. TANNER, W. W. 1944. A taxonomic study of the genus _Hypsiglena_. Great Basin Nat., 5:25-92, December 29. TAYLOR, E. H. 1936a. New species of amphibia from Mexico. Trans. Kansas Acad. Sci., 39:349-363. 1936b. The rediscovery of the lizard _Eumeces altamirani_ (Dugès) with notes on two other Mexican species of the genus. Proc. Biol. Soc. Washington, 49:55-58, May 1. 1936c. A taxonomic study of the cosmopolitan scincoid lizards of the genus _Eumeces_. Univ. Kansas Sci. Bull., 23:1-643, August 15. 1939a. Concerning Mexican salamanders. Univ. Kansas Sci. Bull., 25:259-313, July 10. 1939b. Frogs of the _Hyla eximia_ group in Mexico, with descriptions of two new species. Univ. Kansas Sci. Bull., 25:421-445, July 10. 1940a. A new bromeliad frog from northwestern Michoacan. Copeia, 1940 (1):18-20, March 30. 1940b. Mexican snakes of the genus _Typhlops_. Univ. Kansas Sci. Bull., 26:441-444, November 27. 1940c. Some Mexican serpents. Univ. Kansas Sci. Bull., 26:445-487, November 27. 1940d. Herpetological Miscellany. Univ. Kansas Sci. Bull., 26:489-571, November 27. 1941a. Some Mexican frogs. Proc. Biol. Soc. Washington, 54:87-94, July 31. 1941b. Herpetological Miscellany, No. II. Univ. Kansas Sci. Bull., 27:105-138, December 30. 1942a. New tailless Amphibia from Mexico. Univ. Kansas Sci. Bull., 28:67-89, May 15. 1942b. Tadpoles of Mexican Anura. Univ. Kansas Sci. Bull., 28:37-55, May 15. 1942c. The frog genus _Diaglena_ with a description of a new species. Univ. Kansas Sci. Bull., 28:57-65, May 15. 1943a. Herpetological novelties from Mexico. Univ. Kansas Sci. Bull., 29:343-361, October 15. 1943b. A new _Hylella_ from Mexico. Proc. Biol. Soc. Washington, 56:49-52, June 16. 1952. A new hylid frog of the genus _Agalychnis_ from southwestern Mexico. Copeia, 1952 (1):31-32, June 2. 1956. A review of the lizards of Costa Rica. Univ. Kansas Sci. Bull., 38 (pt. 1):3-322, December 20. TAYLOR, E. H., and SMITH, H. M. 1942a. Concerning the snake genus _Pseudoficimia_ Bocourt. Univ. Kansas Sci. Bull., 28:241-249, November 12. 1942b. The snake genera _Conopsis_ and _Toluca_. Univ. Kansas Sci. Bull., 28:325-363, November 12. 1945. Summary of the collections of amphibians made in Mexico under the Walter Rathbone Bacon Traveling Scholarship. Proc. U. S. Natl. Mus., 95:521-613, June 30. TIHEN, J. A. 1949. A review of the lizard genus _Barisia_. Univ. Kansas Sci. Bull., 33:217-256, April 20. VIVÓ, J. 1953. Geografía de México. Mexico City, ed. 3, 338 pp. WEBB, R. G. 1958. The status of the Mexican lizards of the genus _Mabuya_. Univ. Kansas Sci. Bull., 38:1303-1313, March 2. WELLMAN, J. 1959. Notes on the variation in and distribution of the Mexican colubrid snake _Coniophanes lateritius_. Herpetologica, 15:127-128, September 10. WOODBURY, A. M., and WOODBURY, D. M. 1944. Notes on Mexican snakes from Oaxaca. Jour. Washington Acad. Sci., 34:360-373, November 15. ZWEIFEL, R. G. 1957. A new frog of the genus _Rana_ from Michoacán, Mexico. Copeia, 1957 (2):78-83, July 15. 1959a. Variation in and distribution of lizards of western Mexico related to _Cnemidophorus sacki_. Bull. Amer. Mus. Nat. Hist., 117:57-116, April 27. 1959b. Additions to the herpetofauna of Nayarit, Mexico. Amer. Mus. Novitates, 1953:1-13, June 26. 1959c. Snakes of the genus _Imantodes_ in western Mexico. Amer. Mus. Novitates, 1961:1-18, September 16. 1960. Results of the Puritan-American Museum of Natural History Expedition to western Mexico. 9. Herpetology of the Tres Marías Islands. Bull. Amer. Mus. Nat. Hist., 119:77-128, February 29. 1961. Relationship of two whiptail lizards (genus _Cnemidophorus_) in western Mexico. Copeia, no. 1:98-103, March 17. _Transmitted April 21, 1961._ UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Institutional libraries interested in publications exchange may obtain this series by addressing the Exchange Librarian, University of Kansas Library, Lawrence, Kansas. Copies for individuals, persons working in a particular field of study, may be obtained by addressing instead the Museum of Natural History, University of Kansas, Lawrence, Kansas. There is no provision for sale of this series by the University Library, which meets institutional requests, or by the Museum of Natural History, which meets the requests of individuals. However, when individuals request copies from the Museum, 25 cents should be included, for each separate number that is 100 pages or more in length, for the purpose of defraying the costs of wrapping and mailing. * An asterisk designates those numbers of which the Museum's supply (not the Library's supply) is exhausted. Numbers published to date, in this series, are as follows: Vol. 1. Nos. 1-26 and index. Pp. 1-638. 1946-1950. *Vol. 2. (Complete) Mammals of Washington. By Walter W. Dalquest. Pp. 1-444, 140 figures in text. April 9, 1948. Vol. 3. *1. The avifauna of Micronesia, its origin, evolution, and distribution. By Rollin H. Baker. Pp. 1-359, 18 figures in text. June 12, 1951. 2. A quantitative study of the nocturnal migration of birds. By George H. Lowery, Jr. Pp. 361-472, 47 figures in text. June 29, 1951. 3. Phylogeny of the waxwings and allied birds. By M. Dale Arvey. Pp. 478-530, 49 figures in text, 13 tables. October 10, 1951. 4. Birds from the state of Veracruz, Mexico. By George H. Lowery, Jr., and Walter W. Dalquest. Pp. 531-649, 7 figures in text, 2 tables. October 10, 1951. Index. Pp. 651-681. *Vol. 4. (Complete) American weasels. By E. Raymond Hall. Pp. 1-466, 41 plates, 31 figures in text. December 27, 1951. Vol. 5. Nos. 1-37 and index. Pp. 1-676, 1951-1953. *Vol. 6. (Complete) Mammals of Utah, _taxonomy and distribution_. By Stephen D. Durrant. Pp. 1-549, 91 figures in text, 30 tables. August 10, 1952. Vol. 7. *1. Mammals of Kansas. By E. Lendell Cockrum. Pp. 1-303, 73 figures in text, 37 tables. August 25, 1952. 2. Ecology of the opossum on a natural area in northeastern Kansas. By Henry S. Fitch and Lewis L. Sandidge. Pp. 305-338, 5 figures in text. August 24, 1953. 3. The silky pocket mice (Perognathus flavus) of Mexico. By Rollin H. Baker. Pp. 339-347, 1 figure in text. February 15, 1954. 4. North American jumping mice (Genus Zapus). By Philip H. Krutzsch. Pp. 349-472, 47 figures in text, 4 tables. April 21, 1954. 5. Mammals from Southeastern Alaska. By Rollin H. Baker and James S. Findley. Pp. 473-477. April 21, 1954. 6. Distribution of Some Nebraskan Mammals. By J. Knox Jones, Jr. Pp. 479-487. April 21, 1954. 7. Subspeciation in the montane meadow mouse. Microtus montanus, in Wyoming and Colorado. By Sydney Anderson. Pp. 489-506, 2 figures in text. July 23, 1954. 8. A new subspecies of bat (Myotis velifer) from southeastern California and Arizona. By Terry A. Vaughan. Pp. 507-512. July 23, 1954. 9. Mammals of the San Gabriel mountains of California. By Terry A. Vaughan. Pp. 513-582, 1 figure in text, 12 tables. November 15, 1954. 10. A new bat (Genus Pipistrellus) from northeastern Mexico. By Rollin H. Baker. Pp. 583-586. November 15, 1954. 11. A new subspecies of pocket mouse from Kansas. By E. Raymond Hall. Pp. 587-590. November 15. 1954. 12. Geographic variation in the pocket gopher, Cratogeomys castanops, in Coahuila, Mexico. By Robert J. Russell and Rollin H. Baker. Pp. 591-608. March 15. 1955. 13. A new cottontail (Sylvilagus floridanus) from northeastern Mexico. By Rollin H. Baker. Pp. 609-612. April 8, 1955. 14. Taxonomy and distribution of some American shrews. By James S. Findley. Pp. 613-618. June 10, 1955. 15. The pigmy woodrat, Neotoma goldmani, its distribution and systematic position. By Dennis G. Rainey and Rollin H. Baker. Pp. 619-624. 2 figures in text. June 10, 1955. Index. Pp. 625-651. Vol. 8. Nos. 1-10 and index. Pp. 1-675, 1954-1956. Vol. 9. 1. Speciation of the wandering shrew. By James S. Findley. Pp. 1-68, 18 figures in text. December 10, 1955. 2. Additional records and extensions of ranges of mammals from Utah. By Stephen D. Durrant, M. Raymond Lee, and Richard M. Hansen. Pp. 69-80. December 10, 1955. 3. A new long-eared myotis (Myotis evotis) from northeastern Mexico. By Rollin H. Baker and Howard J. Stains. Pp. 81-84. December 10, 1955. 4. Subspeciation in the meadow mouse, Microtus pennsylvanicus, in Wyoming. By Sydney Anderson. Pp. 85-104, 2 figures in text. May 10, 1956. 5. The condylarth genus Ellipsodon. By Robert W. Wilson. Pp. 105-116, 6 figures in text. May 19, 1956. 6. Additional remains of the multituberculate genus Eucosmodon. By Robert W. Wilson. Pp. 117-123, 10 figures in text. May 19, 1956. 7. Mammals of Coahuila, Mexico. By Rollin H. Baker. Pp. 125-335, 75 figures in text. June 15, 1956. 8. Comments on the taxonomic status of Apodemus peninsulae, with description of a new subspecies from North China. By J. Knox Jones, Jr. Pp. 337-346, 1 figure in text, 1 table. August 15, 1956. 9. Extensions of known ranges of Mexican bats. By Sydney Anderson. Pp. 347-351. August 15, 1956. 10. A new bat (Genus Leptonycteris) from Coahuila. By Howard J. Stains. Pp. 353-356. January 21, 1957. 11. A new species of pocket gopher (Genus Pappogeomys) from Jalisco, Mexico. By Robert J. Russell. Pp. 357-361. January 21, 1957. 12. Geographic variation in the pocket gopher, Thomomys bottae, in Colorado. By Phillip M. Youngman. Pp. 363-387, 7 figures in text. February 21, 1958. 13. New bog lemming (genus Synaptomys) from Nebraska. By J. Knox Jones, Jr. Pp. 385-388. May 12, 1958. 14. Pleistocene bats from San Josecito Cave, Nuevo León, México. By J. Knox Jones, Jr. Pp. 389-396. December 19, 1958. 15. New Subspecies of the rodent Baiomys from Central America. By Robert L. Packard. Pp. 397-404. December 19, 1958. 16. Mammals of the Grand Mesa, Colorado. By Sydney Anderson. Pp. 405-414, 1 figure in text. May 20, 1959. 17. Distribution, variation, and relationships of the montane vole, Microtus montanus. By Emil K. Urban. Pp. 415-511. 12 figures in text, 2 tables. August 1, 1959. 18. Conspecificity of two pocket mice, Perognathus goldmani and P. artus. By E. Raymond Hall and Marilyn Bailey Ogilvie. Pp. 513-518, 1 map. January 14, 1960. 19. Records of harvest mice, Reithrodontomys, from Central America, with description of a new subspecies from Nicaragua. By Sydney Anderson and J. Knox Jones, Jr. Pp. 519-529. January 14, 1960. 20. Small carnivores from San Josecito Cave (Pleistocene), Nuevo León, México. By E. Raymond Hall. Pp. 531-538, 1 figure in text. January 14, 1960. 21. Pleistocene pocket gophers from San Josecito Cave, Nuevo León, México. By Robert J. Russell. Pp. 539-548, 1 figure in text. January 14, 1960. 22. Review of the insectivores of Korea. By J. Knox Jones, Jr., and David H. Johnson. Pp. 549-578. February 23, 1960. 23. Speciation and evolution of the pygmy mice, genus Baiomys. By Robert L. Packard. Pp. 579-670, 4 plates, 12 figures in text. June 16, 1960. Index Pp. 671-690. Vol. 10. 1. Studies of birds killed in nocturnal migration. By Harrison B. Tordoff and Robert M. Mengel. Pp. 1-44, 6 figures in text, 2 tables. September 12, 1956. 2. Comparative breeding behavior of Ammospiza caudacuta and A. maritima. By Glen E. Woolfenden. Pp. 45-75, 6 plates, 1 figure. December 20, 1956. 3. The forest habitat of the University of Kansas Natural History Reservation. By Henry S. Fitch and Ronald R. McGregor. Pp. 77-127, 2 plates, 7 figures in text, 4 tables. December 31, 1956. 4. Aspects of reproduction and development in the prairie vole (Microtus ochrogaster). By Henry S. Fitch. Pp. 129-161, 8 figures in text, 4 tables. December 19, 1957. 5. Birds found on the Arctic slope of northern Alaska. By James W. Bee. Pp. 163-211, pls. 9-10, 1 figure in text. March 12, 1958. 6. The wood rats of Colorado: distribution and ecology. By Robert B. Finley, Jr. Pp. 213-552, 34 plates, 8 figures in text, 35 tables. November 7, 1958. 7. Home ranges and movements of the eastern cottontail in Kansas. By Donald W. Janes. Pp. 553-572, 4 plates, 3 figures in text. May 4, 1959. 8. Natural history of the salamander. Aneides hardyi. By Richard F. Johnston and Schad Gerhard. Pp. 573-585. October 8, 1959. 9. A new subspecies of lizard, Cnemidophorus sacki, from Michoacán, México. By William E. Duellman. Pp. 587-598, 2 figures in text. May 2, 1960. 10. A taxonomic study of the Middle American Snake, Pituophis deppei. By William E. Duellman. Pp. 599-612, 1 plate, 1 figure in text. May 2, 1960. Index Pp. 611-626. Vol. 11. Nos. 1-10 and index. Pp. 1-703, 1958-1960. Vol. 12. 1. Functional morphology of three bats: Eumops, Myotis, Macrotus. By Terry A. Vaughan. Pp. 1-153, 4 plates, 24 figures in text, July 8, 1959. 2. The ancestry of modern Amphibia: a review of the evidence. By Theodore H. Eaton, Jr. Pp. 155-180, 10 figures in text. July 10, 1959. 3. The baculum in microtine rodents. By Sydney Anderson. Pp. 181-218, 49 figures in text. February 19, 1960. 4. A new order of fishlike Amphibia from the Pennsylvanian of Kansas. By Theodore H. Eaton, Jr., and Peggy Lou Stewart. Pp. 217-240, 12 figures in text. May 2, 1960. More numbers will appear in volume 12. Vol. 13. 1. Five natural hybrid combinations in minnows (Cyprinidae). By Frank B. Cross and W. L. Minckley. Pp. 1-18. June 1, 1960. 2. A distributional study of the amphibians of the isthmus of Tehuantepec, México. By William E. Duellman. Pp. 19-72, pls. 1-8, 3 figs. August 16, 1960. 3. A new subspecies of the slider turtle (Pseudemys scripta) from Coahuila, México. By John M. Legler. Pp. 73-84, pis. 9-12, 3 figures in text. August 16, 1960. 4. Autecology of the Copperhead. By Henry S. Fitch. Pp. 85-288, pls. 13-20, 26 figures in text. November 30, 1960. 5. Occurrence of the Garter Snake, Thamnophis sirtalis, in the Great Plains and Rocky Mountains. By Henry S. Fitch and T. Paul Maslin. Pp. 289-308, 4 figures in text. February 10, 1961. 6. Fishes of the Wakarusa River in Kansas. By James E. Deacon and Artie L. Metcalf. Pp. 309-322, 1 figure in text. February 10, 1961. 7. Geographic variation in the North American Cyprinid Fish, Hybopsis gracilis. By Leonard J. Olund and Frank B. Cross. Pp. 323-348, pis. 21-24, 2 figures in text. February 10, 1961. 8. Descriptions of two species of frogs, Genus Ptychohyla--studies of American hylid frogs, V. By William E. Duellman. Pp. 349-357, pl. 25, 2 figures in text. April 27, 1961. 9. Fish populations, following a drought, in the Neosho and Marais des Cygnes rivers of Kansas. By James Everett Deacon. Pp. 359-427, pis. 26-30, 3 figs. in text. August 11, 1961. More numbers will appear in volume 13. Vol. 14. 1. Neotropical bats from western México. By Sydney Anderson. Pp. 1-8. October 24, 1960. 2. Geographic variation in the harvest mouse Reithrodontomys megalotis on the central Great Plains and in adjacent regions. By J. Knox Jones, Jr. and B. Mursaloglu. Pp. 9-27, 1 figure in text. July 24, 1961. 3. Mammals of Mesa Verde National Park, Colorado. By Sydney Anderson. Pp. 29-67, pls. 1-2, 3 figures in text. July 24, 1961. More numbers will appear in volume 14. Vol. 15. 1. The amphibians and reptiles of Michoacán, México. By William E. Duellman. Pp. 1-148, pls. 1-6, 11 figs. December 20, 1961. 
38398	----	================================= UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 15, No. 5, pp. 205-249, pls. 7-10, 6 figs. -------------- October 4, 1963 -------------- Amphibians and Reptiles of the Rainforests of Southern El Petén, Guatemala BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1963 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Vol. 15, No. 5, pp. 205-249, pls. 7-10, 6 figs. Published October 4, 1963 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY JEAN M. NEIBARGER, STATE PRINTER TOPEKA, KANSAS 1963 [Illustration: Printer's Logo] 29-5935 Amphibians and Reptiles of the Rainforests of Southern El Petén, Guatemala BY WILLIAM E. DUELLMAN CONTENTS PAGE INTRODUCTION 207 Acknowledgments 208 DESCRIPTION OF AREA 208 Physiography 209 Climate 209 Vegetation 209 GAZETTEER 210 THE HERPETOFAUNA OF THE RAINFOREST 211 Composition of the Fauna 212 Ecology of the Herpetofauna 212 Relationships of the Fauna 217 ACCOUNTS OF SPECIES 218 HYPOTHETICAL LIST OF SPECIES 246 SUMMARY 247 LITERATURE CITED 247 INTRODUCTION Early in 1960 an unusual opportunity arose to carry on biological field work in the midst of virgin rainforest in southern El Petén, Guatemala. At that time the Ohio Oil Company of Guatemala had an air strip and camp at Chinajá, from which place the company was constructing a road northward through the forest. In mid-February, 1960, J. Knox Jones, Jr. and I flew into El Petén to collect and study mammals, reptiles, and amphibians. While enjoying the comforts of the fine field camp at Chinajá, we worked in the surrounding forest and availed ourselves of the opportunity to be on hand when the road crews were cutting the tall trees in the forest, thereby bringing to the ground many interesting specimens of the arboreal fauna. We stayed at Chinajá until late March, with the exception of a week spent at Toocog, another camp of the Ohio Oil Company located 15 kilometers southeast of La Libertad and on the edge of the savanna. Thus, at Toocog we were able to work both in the forest and on the savanna. In the summer of 1960, John Wellman accompanied me to El Petén for two weeks in June and July. Most of our time was spent at Chinajá, but a few days were spent at Toocog and other localities in south-central El Petén. Many areas in Guatemala have been studied intensively by L. C. Stuart, who has published on the herpetofauna of the forested area of northeastern El Petén (1958), the savannas of central El Petén (1935), and the humid mountainous region to the south of El Petén in Alta Verapaz (1948 and 1950). The area studied by me and my companions is covered with rainforest and lies to the north of the highlands of Alta Verapaz and to the south of the savannas of central El Petén. A few specimens of amphibians and reptiles were obtained in this area in 1935 by C. L. Hubbs and Henry van der Schalie; this collection, reported on by Stuart (1937), contained only one species, _Cochranella fleischmanni_, not present in our collection of 77 species and 617 specimens. Acknowledgments I am grateful to L. C. Stuart of the University of Michigan, who made the initial arrangements for our work in El Petén, aided me in the identification of certain specimens, and helped in the preparation of this report. J. Knox Jones, Jr. and John Wellman were able field companions, who added greatly to the number of specimens in the collection. In Guatemala, Clark M. Shimeall and Harold Hoopman of the Ohio Oil Company of Guatemala made available to us the facilities of the company's camps at Chinajá and Toocog. Alberto Alcain and Luis Escaler welcomed us at Chinajá and gave us every possible assistance. Juan Monteras and Antonio Aldaña made our stay at Toocog enjoyable and profitable. During our visits to southern El Petén, Julio Bolón C. worked for us as a collector, and between March and June he collected and saved many valuable specimens; his knowledge of the forest and its inhabitants was a great asset to our work. Jorge A. Ibarra, Director of the Museo Nacional de Historia Natural in Guatemala assisted us in obtaining necessary permits and extended other kindnesses. To all of these people I am indebted for the essential parts that they played in the completion of this study. Field work in the winter of 1960 was made possible by funds from the American Heart Association for the purposes of collecting mammalian hearts. My field work in the summer of 1960 was supported by a grant from the Graduate Research Fund of the University of Kansas. DESCRIPTION OF THE AREA A vast lowland region stretches northward for approximately 700 kilometers from the highlands of Guatemala to the Gulf of Mexico. The northern two-thirds of this low plain is bordered on three sides by seas and forms the Yucatán Peninsula. The lowlands at the base of the Yucatán Peninsula make up the Departamento El Petén of Guatemala. The area with which this report is concerned consists of the south-central part of El Petén. Physiography Immediately south of Chinajá is a range of hills, the Serrania de Chinajá, having an almost due east-west axis and a crest of about 600 meters above sea level. South of the Serrania de Chinajá are succeedingly higher ridges building up to the Meseta de Cobán and Sierra de Pocolha and eventually to the main Guatemalan highlands. The northern face of the Serrania de Chinajá is a fault scarp dropping abruptly from about 650 meters at the crest to about 140 meters at the base. From the base of the Serrania de Chinajá northward to the Río de la Pasión at Sayaxché the terrain is gently rolling and has a total relief of about 50 meters. North of the Río de la Pasión is a low dome reaching an elevation of 170 meters at La Libertad; see Stuart (1935:12) for further discussion of the physiography of central El Petén. The rocks in southern El Petén are predominately Miocene marine limestones; there are occasional pockets of Pliocene deposits. There is little evidence of subterranean solution at Chinajá, but northward in central El Petén karsting is common. The upper few inches of soil is humus rich in organic matter; below this is clay. Climate The climate of El Petén is tropical with equable temperatures throughout the year. Temperatures at Chinajá varied between a night-time low of 65° F. and a daytime high of 91° F. during the time of our visits. In the Köppen system of classification the climate at Chinajá and Toocog is Af. Rain falls throughout the year, but there is a noticeable dry season. To anyone who has traveled from south to north in El Petén and the Yucatán Peninsula, it is obvious from the changes in vegetation that there is a decrease in rainfall from south to north. There is a noticeable difference between Chinajá and Toocog. Although rainfall data are not available for Chinajá and Toocog, there are records for nearby stations (Sapper, 1932). At Paso Caballos on the Río San Pedro about 40 kilometers northwest of Toocog the average annual rainfall amounts to 1620 mm.; the driest month is March (21 mm.), and the wettest months are June (269 mm.) and September (265 mm.). At Cubilquitz, Alta Verapaz, about 35 kilometers south-southwest of Chinajá and at an elevation of 300 meters, the average annual rainfall is 4006 mm.; the driest month is March (128 mm.), and the wettest months are July (488 mm.) and October (634 mm.). During the 18 days in February and March, 1960, that we kept records on the weather at Chinajá moderate to heavy showers occurred on seven days. During our stay there in June and July rain fell every day, as it did in Toocog. However, during the week spent at Toocog in March no rain fell. Vegetation The vegetation of northern and central El Petén has been studied by Lundell (1937), who made only passing remarks concerning the plants of the southern part of El Petén. No floristic studies have been made there. The following remarks are necessarily brief and are intended only to give the reader a general picture of the forest. I have included names of a few of the commoner trees that I recognized. Chinajá is located in a vast expanse of unbroken rainforest. In this forest there is a noticeable stratification of the vegetation. Three strata are apparent; in the uppermost layer the tops of the trees are from 40 to 50 meters above the ground. The spreading crowns of the trees and the interlacing vines form a nearly continuous canopy over the lower layers. Among the common trees in the upper stratum are _Calophyllum brasiliense_, _Castilla elastica_, _Cedrela mexicana_, _Ceiba pentandra_, _Didalium guianense_, _Ficus_ sp., _Sideroxylon lundelli_, _Swietenia macrophylla_, and _Vitex_ sp. (Pl. 1, fig. 1). The middle layer of trees have crowns about 25 meters above the ground; these trees in some places where the upper canopy is missing form the tallest trees in the forest. This is especially true on steep hillsides. Common trees in the middle layer include _Achras zapote_, _Bombax ellipticum_, _Cecropia mexicana_, _Orbignya cohune_, and _Sabal_ sp. The lowermost layer reaches a height of about 10 meters; in many places in the forest this layer is absent. Common trees in the lower stratum include _Crysophila argentea_, _Cymbopetalum penduliflorum_, _Casearia_ sp., and _Hasseltia dioica_. The ground cover is sparce; apparently only a few small herbs and ferns live on the heavily shaded forest floor. Important herpetological habitats include the leaf litter, rotting stumps, and rotting tree trunks on the forest floor and the buttresses of many of the gigantic trees, especially _Ceiba pentandra_ (Pl. 2). Epiphytes, especially various kinds of bromeliads, are common. Most frequently these are in the trees in the upper and middle strata. At Toocog there is sharp break between savanna and forest (Pl. 7, fig. 2). The forest is noticeably drier and more open than at Chinajá (Pl. 9). The crowns of the trees are lower, and there is no nearly continuous canopy between 40 and 50 meters above the ground. Although _Swietenia macrophylla_ and other large trees occur, they are less common than at Chinajá. Especially common at Toocog are _Achras zapote_, _Brosimum alicastrum_, and various species of _Ficus_. GAZETTEER The localities from which specimens were obtained are cited below and shown on the accompanying map (Fig. 1). [Illustration: FIG. 1. Map of El Petén, Guatemala, showing localities mentioned in text.] Chinajá.--Lat. 16° 02´, long. 90° 13´, elev. 140 m. Camp of the Ohio Oil Company of Guatemala and formerly a small settlement. On some maps Chinajá is located just to the north of the Alta Verapaz--El Petén boundary; recent surveys place the location just to the south of the imaginary line through the rainforest. Field work was conducted in the immediate vicinity of the camp, on the lower slopes of the Serrania de Chinajá, and at several sites to the northwest and north-northwest of Chinajá, where the forest was being cleared. The entire area supports rainforest. La Libertad.--Lat. 16° 47´, long. 90° 07´, elev., 170 m. A town on the savannas in central El Petén; although we collected there in the rainy season, the specimens obtained on the savannas are not included in this report. Paso Subín.--Lat. 16° 38´, long. 90° 12´, elev. 90 m. A small settlement on the Río Subín, a tributary of the Río de la Pasión. Specimens were obtained in rainforest in the immediate vicinity of the settlement. Río de la Pasión.--A large river flowing northward through southern El Petén and thence westward into the Río Usumacinta. Specimens were obtained along the river between the Río Subín and Sayaxché. Río San Román.--A river flowing northward in south-central El Petén to the Río Salinas (Usumacinta). We collected along the river at a place about 16 kilometers north-northwest of Chinajá, approximately at Lat. 16° 10´, long. 90° 17´, elev. 110 m. In the dry season the river was clear; it is surrounded by rainforest. Sayaxché.--Lat. 16° 31´, long. 90° 09´, elev. 80 m. A town on the southern bank of the Río de la Pasión. Specimens were obtained in the rainforest and in cleared areas in the immediate vicinity of the town. Toocog (formerly Sojío).--Lat. 16° 41´, long. 90° 02´, elev. 140 m. A camp of the Ohio Oil Company of Guatemala located at the rainforest-savanna edge, 15 kilometers southeast of La Libertad. Although we collected on the savannas as well as in the forest, especially to the east of the camp, only species obtained in the forest are considered in this report. THE HERPETOFAUNA OF THE RAINFOREST In presenting an account of the herpetofauna of southern El Petén three items need to be considered: (1) The composition of the fauna; (2) the ecology of the fauna; (3) the relationships of the fauna. Each of these topics is discussed briefly below. Logically a discussion of the origin of the fauna should follow, but this is being withheld for inclusion in a report on the herpetofauna of the entire El Petén by L. C. Stuart and the author; at that time the above topics will be expanded to cover the herpetofauna of the whole region. Composition of the Fauna TABLE 1.--COMPOSITION OF THE HERPETOFAUNA IN SOUTHERN EL PETÉN, GUATEMALA. =============+============+============+============ Group | Families | Genera | Species -------------+------------+------------+------------ Gymnophiona | (1)[A] | (1) | (1) Caudata | 1 | 1 | 2 Salientia | 6 | 10 (1) | 19 (1) Crocodilia | 1 | 1 | 1 Testudines | 4 | 7 | 8 Sauria | 6 | 13 (1) | 19 (1) Serpentes | 4 | 21 (7) | 29 (10) +------------+------------+------------ Total | 22 (1) | 53 (10) | 78 (13) -------------+------------+------------+------------ [Footnote A: Numbers in parenthesis indicate the number of additional taxa that probably occur.] A total of 78 species of amphibians and reptiles has been found in the rainforests in southern El Petén; a break down into families and genera is given in table 1. Another 13 species probably occur in southern El Petén (see Hypothetical List of Species). The fauna primarily is composed of typical humid lowland forest inhabitants, such as: _Hyla ebraccata_ _Hyla loquax_ _Phyllomedusa callidryas taylori_ _Smilisca phaeota cyanosticta_ _Anolis biporcatus_ _Anolis capito_ _Anolis humilis uniformis_ _Eumeces sumichrasti_ _Ameiva festiva edwardsi_ _Imantodes cenchoa leucomelas_ _Leptophis ahaetulla praestans_ _Xenodon rabdocephalus mexicanus_ _Bothrops nasutus_ _Bothrops schlegeli schlegeli_ Nevertheless, the region also provides at least a limited amount of habitat suitable for some species that are more frequently found in open forest of a drier nature; such species include: _Hyla microcephala martini_ _Hyla staufferi_ _Hypopachus cuneus nigroreticulatus_ _Anolis sericeus sericeus_ _Eumeces schwartzei_ _Oxybelis aeneus aeneus_ Because of the absence of sufficiently open habitat or owing to the presence of competitors, some conspicuous members of sub-humid forests are not present in southern El Petén. Conspicuous absentees are the following: _Rhinophrynus dorsalis_ _Phrynohyas spilomma_ _Triprion petasatus_ _Anolis tropidonotus_ _Ctenosaura similis_ _Ameiva undulata_ _Cnemidophorus angusticeps_ _Conophis lineatus_ _Masticophis mentovarius mentovarius_ PLATE 7 [Illustration: FIG. 1. Edge of rainforest along airstrip at Chinajá, El Petén, Guatemala.] [Illustration: FIG. 2. Rainforest at edge of savanna at Toocog, El Petén, Guatemala.] PLATE 8 [Illustration: Interior of rainforest at Chinajá. Notice size of buttresses on large tree (_Ceiba pentandra_).] PLATE 9 [Illustration: Interior of rainforest at Toocog. Notice less dense vegetation as compared with Pl. 8.] PLATE 10 [Illustration: FIG. 1. Rainforest along Río San Román, 16 kilometers north-northwest of Chinajá.] [Illustration: FIG. 2. Rain pond in forest at Toocog. This was a breeding site for six species of frogs.] Ecology of the Herpetofauna Our two visits to Chinajá and Toocog afforded the opportunity to gather data on the ecology of the rainforests of southern El Petén and to study the relationships between the environment and members of the herpetofauna. Tropical rainforests present the optimum conditions for life, and it is in this environment that life reaches its greatest diversity. Here, too, biological inter-relationships are most complex. This complexity is illustrated by the presence of many species of some genera, all of which are found together in the same geographic region. In the rainforests of southern El Petén there are six species of _Anolis_, five of _Hyla_, four of _Bothrops_, and three of _Coniophanes_. Obviously, the diversity of ecological niches in the rainforest is sufficient to support a variety of related species. Of the examples mentioned above, fairly adequate ecological data were obtained for most of the species of _Anolis_, which will be used to show the ecological diversity and vertical stratification of sympatric species in the rainforests. Of the six species of _Anolis_, all except _A. sericeus_ are typically found in humid forests. _Anolis sericeus sericeus_ is poorly represented in the collections from southern El Petén, where it may be in competition with _Anolis limifrons rodriguezi_ that resembles _Anolis s. sericeus_ in size, coloration, and habits. Therefore, _Anolis sericeus sericeus_ is excluded from the following discussion. The common terrestrial species is _Anolis humilis uniformis_; sometimes this small species perches or suns on the bases of small trees or buttresses of some large trees. When disturbed it takes to the ground and seeks cover in the leaf litter or beneath logs or palm fronds. _Anolis lemurinus bourgeaei_ is about twice the size of _Anolis humilis uniformis_ and is usually observed on buttresses of large trees or on the lower two meters of tree trunks. Individuals were seen foraging on the ground along with _Anolis humilis uniformis_. At no time were _Anolis lemurinus bourgeaei_ observed to ascend the trunks of large trees; they always took refuge near the bases of trees. _Anolis limifrons rodriguezi_ is found on the stems and branches of bushes. It is a small species that sometimes is observed on the ground but was never seen ascending large trees. _Anolis capito_ is about the same size as _Anolis lemurinus bourgeaei_ and lives on the trunks of large trees. In the tops of the trees lives a large green species, _Anolis biporcatus_. Similar segregation habitatwise can be demonstrated for other members of the herpetofauna. The avoidance of interspecific competition in feeding is well illustrated by three species of snakes that probably are the primary ophidian predators on frogs. _Drymobius margaritiferus margaritiferus_ is diurnal and terrestrial; it feeds on frogs at the edges of breeding ponds by day. Also during the day _Leptophis mexicanus mexicanus_ feeds on frogs in bushes and trees. At night the activities of both of these species is replaced by those of _Leptodeira septentrionalis polysticta_, which not only feeds on the frogs in the trees and bushes, but descends to the ground and even enters the water in search of food. From the examples discussed above, the importance of the three dimensional aspect of the rainforest is apparent. The presence of a large and diverse habitat above the ground is of great significance in the rainforest, for of the non-aquatic components of the herpetofauna in the rainforests of southern El Petén, 42 per cent of the species spend at least part of their lives in the bushes and trees. Another important part of the forest is the subterranean level--the rich mulch, underground tunnels, and rotting subterranean vegetation. Of the 78 species of amphibians and reptiles in southern El Petén, seven are primarily fossorial, and half-a-dozen others are secondarily fossorial. Probably the fossorial members of the fauna are the least well represented in the collection, for such widespread species as _Dermophis mexicanus mexicanus_, _Rhadinaea decorata decorata_ and _Tantilla schistosa schistosa_ were expected, but not found. In the following discussion of the ecological distribution of amphibians and reptiles in the rainforest I have depended chiefly on my observations made in southern El Petén, but have taken into consideration observations made on the same species in other regions, together with reports from other workers. The reader should keep in mind that the evidence varies from species to species. Of some species I have observed only one animal in the field; of others, I have seen scores and sometimes hundreds of individuals. For species on which I have few observations or rather inconclusive evidence, the circumstance of inadequate data is mentioned. In analyzing the ecological distribution within the forest, it is convenient to recognize five subdivisions (habitats); each is treated below as a unit. 1. AQUATIC.--This habitat includes permanent streams and rivers (Pl. 10, fig. 1), some of which are clear and others muddy. In the rainy season temporary ponds form in depressions on the forest floor (Pl. 10, fig. 2); these are important as breeding sites for many species of amphibians. Aquatic members of the herpetofauna are here considered to be those species that either spend the greatest part of their lives in the water or usually retreat to water for shelter. Seven species of turtles and one crocodilian are aquatic. Of these, _Dermatemys mawi_, _Staurotypus triporcatus_, and _Pseudemys scripta ornata_ inhabit clear water, whereas _Chelydra rossignoni_, _Claudius angustatus_, _Kinosternon acutum_, and _K. leucostomum_ inhabit muddy water. _Crocodylus moreleti_ apparently inhabits both clear and muddy water, for in the dry season it lives along the clear rivers, but in the rainy season inhabits flooded areas in the forest as well. 2. AQUATIC MARGIN.--Extensive marshes were lacking in the part of southern El Petén that I visited; consequently, the aquatic margin habitat is there limited to the edges of rivers and borders of temporary ponds. _Bufo marinus_, _Rana palmipes_, and _Rana pipiens_ are characteristic inhabitants of the aquatic margin, although in the rainy reason _Bufo marinus_ often is found away from water. Observations indicate that _Tretanorhinus nigroluteus lateralis_ inhabits the margins of ponds and streams and actually spends considerable time in the water. Although _Iguana iguana rhinolopha_ is arboreal, it lives in trees along rivers, into which it plunges upon being disturbed. Species included in this category are those that customarily spend most of their lives at the edge of permanent water. Frogs and toads that migrate to the water for breeding and the snakes that prey on the frogs at that time are not assigned to the aquatic-margin habitat. 3. FOSSORIAL.--Characteristic inhabitants of the mulch on the forest floor are _Bolitoglossa moreleti mulleri_, _Lepidophyma flavimaculatum flavimaculatum_, _Scincella cherriei cherriei_, _Ninia sebae sebae_, _Pliocercus euryzonus aequalis_, and _Micrurus affinis apiatus_. Other species of snakes that spend most of their lives above ground often forage in the mulch layer; among these are _Coniophanes bipunctatus biserialis_, _Coniophanes fissidens fissidens_, _Coniophanes imperialis clavatus_, _Lampropeltis doliata polyzona_, and _Stenorrhina degenhardti_. Among the amphibians, at least _Hypopachus cuneus nigroreticulatus_, _Eleutherodactylus rostralis_, and _Syrrhophus leprus_ are known to seek shelter in the mulch. 4. TERRESTRIAL.--One turtle, _Geoemyda areolata_, is primarily terrestrial. Among the lizards, conspicuous terrestrial species are _Anolis humilis uniformis_ and _Ameiva festiva edwardsi_; _Anolis lemurinus bourgeaei_ and _Basiliscus vittatus_ spend part of their lives on the ground, but also live on trees and in bushes. _Eumeces schwartzei_ and _E. sumichrasti_ apparently are terrestrial. The only terrestrial lizard that is nocturnal is _Coleonyx elegans elegans_, which by day hides in the leaf litter or below ground. Nocturnal amphibians that are terrestrial include _Bufo marinus_, _Bufo valliceps valliceps_, _Eleutherodactylus rugulosus rugulosus_, _Syrrhophus leprus_, and _Hypopachus cuneus nigroreticulatus_. A large number of active diurnal snakes are terrestrial; these include _Boa constrictor imperator_, _Clelia clelia clelia_, _Dryadophis melanolomus laevis_, _Drymarchon corais melanurus_, _Drymobius margaritiferus margaritiferus_, _Pseustes poecilonotus poecilonotus_, and _Spilotes pullatus mexicanus_. Nocturnal terrestrial snakes include three kinds of _Bothrops_ (_B. atrox asper_, _B. nasutus_, and _B. nummifer nummifer_), all of which seem to be equally active by day. 5. ARBOREAL.--In this habitat the third dimension (height) of the rainforest probably is the most complex insofar as the inter-relationships of species and ecological niches are concerned. I have attempted to categorize species as to microhabitats within the arboreal habitat; in so doing, I recognize four subdivisions--bushes, tree trunks, tree tops, and epiphytes. Bush inhabitants include several species of lizards and snakes, all of which have rather elongate, slender bodies, and long tails. Common bush-inhabitants in southern El Petén are _Anolis limifrons rodriguezi_, _Basiliscus vittatus_, _Laemanctus deborrei_, _Leptophis mexicanus mexicanus_, and _Oxybelis aeneus aeneus_. All of these are diurnal, and all but _Laemanctus_ have been observed sleeping on bushes at night. Tree-trunk inhabitants include five species of lizards. _Thecadactylus rapicaudus_ lives on the trunks of large trees; _Sphaerodactylus lineolatus_ lives beneath the bark on dead trees and on corozo palms. _Anolis lemurinus bourgeaei_ lives on the bases and buttresses of large trees, from which it often descends to the ground. _Corythophanes cristatus_ and _Anolis capito_ were found only on tree trunks and large vines. The least information is available for the species living in the tree tops. The following species were obtained from tops of trees when they were felled, or have been observed living in the tree tops: _Anolis biporcatus_, _Iguana iguana rhinolopha_, _Celestus rozellae_, _Leptodeira septentrionalis polysticta_, _Leptophis ahaetulla praestans_, _Sibon dimidiata dimidiata_, and _Sibon nebulata nebulata_. Epiphytes, especially the bromeliads, provide refuge for a variety of tree frogs and small snakes. Of the tree frogs, _Hyla picta_, _Hyla staufferi_, _Phyllomedusa callidryas taylori_, _Similisca baudini_, and _Similisca phaeota cyanosticta_ have been found in bromeliads; other species probably occur there. Among the snakes, _Imantodes cenchoa leucomelas_, _Leptodeira frenata malleisi_, _Leptodeira septentrionalis polysticta_, _Sibon dimidiata dimidiata_, and _Sibon nebulata nebulata_ are frequent inhabitants of bromeliads; all of these snakes are nocturnal. Relationships of the Fauna Most of the 78 species of amphibians and reptiles definitely known from the rainforest in southern El Petén have extensive ranges in the Atlantic lowlands of southern México and Central America; many extend into South America. Sixty-two (80%) of the species belong to this group having extensive ranges in Middle America. Three species (_Syrrhophus leprus_, _Leptodeira frenata_, and _Kinosternon acutum_) are at the southern limits of their distributions in southern El Petén and northern Alta Verapaz, whereas _Eleutherodactylus rostralis_ and _Thecadactylus rapicaudus_ are at the northern and western limits of their distributions in El Petén. Nine (11%) species have the center of their distributions in El Petén and the Yucatán Peninsula; representatives of this group include _Claudius angustatus_, _Dermatemys mawi_, _Laemanctus deborrei_, and _Eumeces schwartzei_. In determining a measure of faunal resemblance, I have departed from the formulae discussed by Simpson (1960) and have analyzed the degree of resemblance by the following formula used to calculate an index of faunal relationships: C (2) / (N_{1} + N_{2}) = R, where C = species common to both faunas. N_{1} = number of species in the first fauna. N_{2} = number of species in the second fauna. R = degree of relationships (when R = 1.00, the faunas are identical; when R = 0, the faunas are completely different). The herpetofauna of southern El Petén has been compared with that in the Tikal-Uaxactún area (Stuart, 1958), that in the humid lowlands of Alta Verapaz (Stuart, 1950, plus additional data), and that in the Mexican state of Yucatán (Smith and Taylor, 1945, 1948, and 1950). The herpetofaunas of lowland Alta Verapaz and Yucatán are the largest, having respectively 94 and 91 species, where as there are 78 species known from southern El Petén and 64 from the Tikal-Uaxactún area. An analysis of faunal relationships (Table 2) shows that the faunas of the rainforests of southern El Petén and lowland Alta Verapaz are closely related. The relationships between these two areas and the Tikal-Uaxactún area in northern El Petén is notably less. Apparently the biggest faunal changes take place between southern El Petén and the Tikal-Uaxactún area, and between the latter and Yucatán. As stated by Stuart (1958:7) the Tikal-Uaxactún is transitional between the humid rainforests to the south and the dry outer end of the Yucatán Peninsula. The transitional nature of the environment is exemplified by a rather depauperate herpetofauna consisting of some species of both dry and humid environments and lacking a large fauna typical of either. Contrariwise, the continuity of the environment from southern El Petén to the lowlands of Alta Verapaz is reflected in degree of resemblance of the herpetofaunas. TABLE 2.--INDEX OF FAUNAL RELATIONSHIPS BETWEEN SOUTHERN EL PETÉN AND OTHER REGIONS. ======================+==========+==========+==========+========== | Lowland | Southern | Tikal- | | Alta | El | Uaxactún | Yucatán | Verapaz | Petén | Area | ----------------------+----------+----------+----------+---------- Lowland Alta Verapaz | | .85 | .61 | .43 ----------------------+----------+----------+----------+---------- Southern El Petén | .85 | | .64 | .41 ----------------------+----------+----------+----------+---------- Tikal-Uaxactún Area | .61 | .64 | | .63 ----------------------+----------+----------+----------+---------- Yucatán | .43 | .41 | .63 | ----------------------+----------+----------+----------+---------- Most of the species of amphibians and reptiles found in southern El Petén are found in humid tropical forests from the Isthmus of Tehuantepec southeastward on the Atlantic lowlands well into Central America. ACCOUNTS OF SPECIES In the following pages various aspects of the occurrence, life histories, ecology, and variation of the species of amphibians and reptiles known from southern El Petén are discussed. Only _Cochranella fleischmanni_ reported by Stuart (1937) from Río Subín at Santa Teresa was not collected by us and is excluded. Because more worthwhile information was gathered for some species than others, the length and completeness of the accounts vary. All specimens listed are in the Museum of Natural History at the University of Kansas, to which institution all catalog numbers refer. Preceding the discussion of each species is an alphabetical list of localities from which specimens were obtained; numbers after a locality indicate the number of specimens obtained at each locality. =Bolitoglossa dofleini= (Werner) Chinajá, 1. An adult female having minute ovarian eggs has a snout-vent length of 81 mm., a tail length of 59 mm., 13 costal grooves, two intercostal spaces between adpressed toes, 38-35 vomerine teeth in irregular rows forming a broad arch from a point posterolaterad to the internal nares to a point near the anterior edge of the parasphenoid teeth, and 43-44 maxilliary-premaxillary teeth. In life the dorsum was rusty brown with irregular black and orange spots and streaks. The flanks were bluish gray with black in the costal grooves and creamy tan flecks along the ventral edge of the flank. The belly and underside of the tail were yellowish tan with dark brown spots laterally. The limbs were orange proximally and black distally; the pads of the feet were bluish black. The dorsal and lateral surfaces of the tail were yellowish orange with black spots. The iris was grayish yellow. Stuart (1943:17) reported this species from Finca Volcán, Alta Verapaz. He diagnosed his specimens as having 13 costal grooves and two or three intercostal spaces between adpressed toes. He stated that the vomerine teeth were about 12 in number and that in life the dorsum was mottled gray and black, the sides gray and brown, and the undersurfaces uniformly dark gray. These specimens differ noticeably from the individual from Chinajá in the number of vomerine teeth and in coloration. In August, 1961, I obtained a specimen of _Bolitoglossa dofleini_ at Finca Los Alpes, Alta Verapaz, approximately 13 kilometers airline south-southwest of Finca Volcán and at approximately the same elevation. Although the salamander was dead when found, it obviously was more heavily pigmented than the individual from Chinajá. The belly was bluish gray with black spots laterally; the dorsum was dull brownish gray with some brownish red streaks. The specimen is a female having small ovarian eggs, a snout-vent length of 90 mm., 13 costal grooves, and two intercostal spaces between adpressed limbs. There are 28-29 vomerine teeth, more than twice as many as in specimens from Finca Volcán (Stuart, 1943:17), but noticeably fewer than in the specimen from Chinajá. The presence of this species at Chinajá lends support to the idea that the specimen from the Río de la Pasión listed by Brocchi (1882:116) also is _Bolitoglossa dofleini_. Furthermore, the confirmed presence of this species in the lowlands of El Petén suggests that there may be genetic connection between _B. dofleini_ in the Alta Verapaz and _B. yucatana_ in the Yucatán Peninsula. _Bolitoglossa yucatana_ differs from _B. dofleini_ in having five intercostal spaces between adpressed toes and in having a different color pattern. Both are robust species having no close relationships to other species of _Bolitoglossa_ in northern Central America. The specimen from Chinajá was found in water in the axil of a large elephant-ear plant (_Xanthosoma_) by day in March. Its stomach contained fragments of beetles and a large roach. The natives did not know salamanders and had no name for them. =Bolitoglossa moreleti mulleri= (Brocchi) Chinajá, 2; Río San Román, 1. One specimen is a female having a snout-vent length of 80 mm., a tail length of 82 mm., and a total length of 162 mm. It contains 63 large eggs, the largest of which has a diameter of about three millimeters. This specimen has 13 costal grooves, four intercostal spaces between adpressed toes, and 12-13 vomerine teeth. A juvenile having a snout-vent length of 39 mm. and a tail length of 33 mm. has 12 costal grooves, three intercostal spaces between adpressed toes, and 8-8 vomerine teeth. In life these salamanders were uniformly dull brownish black above with a dull creamy yellow irregular dorsal stripe beginning on the occiput and continuing onto the tail. There are no yellow or orange streaks or flecks on the head or limbs. The specimen from the Río San Román was taken from the stomach of a _Pliocercus euryzonus aequalis_ and has not been studied in detail, because of its poor condition. The present specimens show no tendency for the development of a broad irregular dorsal band that encloses black spots or forms irregular dorsolateral stripes, as is characteristic of _B. moreleti mexicanus_, a subspecies that has been reported from La Libertad (Stuart, 1935:35) and Piedras Negras (Taylor and Smith, 1945:545) in El Petén, and from Xunantunich, British Honduras (Neill and Allen, 1959:20). Schmidt (1936:151) and Stuart (1943:13) found _B. moreleti mulleri_ in bromeliads at Finca Samac, Alta Verapaz. Taylor and Smith's (1945:545) and Neill and Allen's (1959:20) specimens of _B. moreleti mexicanus_ were obtained from bromeliads, but Neill and Allen (_loc. cit._) stated that the natives in British Honduras said that they had found salamanders beneath rubbish on the forest floor. My specimens were obtained from beneath logs on the forest floor in the rainy season. Possibly in drier environments the species characteristically inhabits bromeliads, at least in the dry season. =Bufo marinus= (Linnaeus) Chinajá, 3; 10 km. NNW of Chinajá, 1; 11 km. NNW of Chinajá, 1. During both visits to Chinajá this large toad was breeding in a small permanent pond in the camp. During the day the toads took refuge in crevices beneath the buildings or beneath large boulders by the pond. At dusk from four to ten males congregated at the pond and called. Tadpoles of this species were in the pond in March and in July. One juvenile was found beneath a rock in the forest, and another was on the forest floor by day. The natives' name for this species and the following one is _sapo_. =Bufo valliceps valliceps= Wiegmann Chinajá, 52; Río San Román, 8; Sayaxché, 2; Toocog, 1. This is one of the most abundant, or at least conspicuous, amphibians inhabiting the forest. Breeding congregations were found on February 24, March 2, March 11, and June 27. At these times the toads were congregated at temporary ponds in the forest or along small sluggish streams. Throughout the duration of both visits to Chinajá individual males called almost nightly at the permanent pond at the camp. The variation in snout-vent length of 20 males selected at random is 56.7 to 72.5 mm. (average, 64.8 mm.). Two adult females have snout-vent lengths of 80.4 and 87.6 mm. In all specimens the parotid glands are somewhat elongated and not rounded as in _Bufo valliceps wilsoni_ (see Baylor and Stuart, 1961:199). My observations on the condition of the cranial crests of the toads in El Petén agree with the findings of Baylor and Stuart (_op. cit._:198) in that hypertrophied crests are usual in large females. In the shape of the parotids and nature of the cranial crests the specimens from El Petén are like those from the Isthmus of Tehuantepec in México. As I pointed out (1960:53), the validity of the subspecies _Bufo valliceps macrocristatus_, described from northern Chiapas by Firschein and Smith (1957:219) and supposedly characterized by hypertrophied cranial crests, is highly doubtful. In the toads from El Petén the greatest variation is in coloration. The dorsal ground-color varies from orange and rusty tan to brown, yellowish tan, and pale gray. In some individuals the flanks and dorsum are one continuous color, whereas in others a distinct dorsolateral pale colored band separates the dorsal color from dark brown flanks. In some individuals the venter is uniform cream color, in others it bears a few scattered black spots, and in still others there are many spots, some of which are fused to form a black blotch on the chest. In breeding males the vocal sac is orange tan. All specimens have a coppery red iris. Aside from the breeding congregations, active toads were found on the forest floor at night; a few were there by day. Some individuals were beneath logs during the day. =Eleutherodactylus rostralis= (Werner) Chinajá, 10. Because of the multiplicity of names and the variation in coloration, the small terrestrial _Eleutherodactylus_ in southern México and northern Central America are in a state of taxonomic confusion. Stuart (1934:7, 1935:37, and 1958:17) referred specimens from El Petén to _Eleutherodactylus rhodopis_ (Cope). Stuart (1941b:197) described _Eleutherodactylus anzuetoi_ from Alta Verapaz and El Quiché, Guatemala, suggested that the new species was an upland relative of _Eleutherodactylus rostralis_ (Werner), and used that name for the frogs that he earlier had referred to _Eleutherodactylus rhodopis_. Dunn and Emlen (1932:24) placed _E. rostralis_ in the synonymy of _E. gollmeri_ (Peters). Examination of series of these frogs from southern México, Guatemala, and Costa Rica causes me to think that there are four species; these can be distinguished as follows: _E. rhodopis._--No web between toes; one tarsal tubercle; tibiotarsal articulation reaches to nostril; iris bronze in life. _E. anzuetoi._--No web between toes; a row of tarsal tubercles; tibiotarsal articulation reaches to tip of snout; color of iris unknown. _E. rostralis._--A vestige of web between toes; no tarsal tubercles; tibiotarsal articulation reaches snout or slightly beyond; iris coppery red in life. _E. gollmeri._--A vestige of web between toes; no tarsal tubercles; tibiotarsal articulation reaches well beyond snout; iris coppery red in life. The presence of webbing between the toes, the absence of tarsal tubercles, and the coppery red iris distinguish _E. rostralis_ and _E. gollmeri_ from the other species. Probably _E. rostralis_ and _E. gollmeri_ are conspecific, but additional specimens are needed from Nicaragua and Honduras to prove conspecificity. On the other hand, the characters of the frogs from Chinajá clearly show that they are related to _E. gollmeri_ to the south and not to _E. rhodopis_ to the north in México. At Chinajá, _Eleutherodactylus rostralis_ was more abundant than the few specimens indicate, for upon being approached the frogs moved quickly and erratically, soon disappearing in the leaf litter on the forest floor. Most of the specimens were seen actively moving on the forest floor in the daytime; one was found beneath a rock, and one was on the forest floor at night. =Eleutherodactylus rugulosus rugulosus= (Cope) Chinajá, 2; 15 km. NW of Chinajá, 4. These frogs were found on the forest floor by day. With the exception of one female having a snout-vent length of 69.5 mm., all are juveniles. The apparent rarity of this species at Chinajá may be due to the absence of rocky streams, a favorite habitat of this frog. The local name for this frog is _sapito_, meaning little toad. =Leptodactylus labialis= (Cope) Toocog, 1. One juvenile having a snout-vent length of 16.4 mm. was found at night beside a pond in the forest. The scarcity of the species of _Leptodactylus_ in the southern part of El Petén probably is due to the lack of permanent marshy ponds. =Leptodactylus melanonotus= (Hallowell) Sayaxché, 1. One individual was found beneath a rock beside a stream in the forest. The local name is _ranita_, meaning little frog. =Syrrhophus leprus= Cope Chinajá, 2; 15 km NW of Chinajá, 1. An adult female having a snout-vent length of 27.5 mm. was found on the forest floor by day. Two juveniles having snout-vent lengths of 15.5 and 19.0 mm. were beneath rocks on the forest floor. The specimens are typical of the species as defined by Duellman (1958:8). =Hyla ebraccata= Cope Toocog, 66. This small tree frog congregated in large numbers at a forest pond at Toocog. Between June 30 and July 2 we collected specimens and observed the breeding habits of this and other species at the pond. Calling males were distributed around the pond, where they called from low herbaceous vegetation at the edge of the pond or from plants rising above the water. Calling commenced at dusk and continued at least into the early hours of the morning. On one occasion a female was observed at a distance of about 50 centimeters away from a calling male sitting on a blade of grass. The female climbed another blade of grass until she was about eight centimeters away from the male, at which time he saw her, stopped calling, jumped to the blade of grass on which she was sitting and clasped her. Clasping pairs were observed on blades of grass and leaves of plants above the water; most pairs were less than 50 centimeters above the surface of the pond. The eggs are deposited on the dorsal surfaces of leaves above the water. All eggs are in one plane (a single layer) on the leaf. External membranes are barely visible, as the eggs consist of a single coherent mass. Eggs in the yolk plug stage have diameters of 1.2 to 1.4 mm. Seventeen eggs masses were found; these contained from 24 to 76 (average 44) eggs. The jelly is extremely viscous and tacky to the touch. At time of hatching the jelly becomes less viscous; the tadpoles wriggle until they reach the edge of the leaf and drop into the water. Eleven tadpoles were preserved as they hatched; these have total lengths of 4.5 to 5.0 (average 4.77) mm. Hatchling tadpoles are active swimmers and have only a small amount of yolk. The largest tadpoles preserved have total lengths of 13.0 and 13.5 mm. At this size distinctive sword-tail and bright coloration have developed. [Illustration: FIG. 2. Tadpole of _Hyla ebraccata_ (KU 59986) from Toocog, El Petén, Guatemala. × 6.] Description of fully developed tadpole (KU 59986): Total length, 13.5 mm.; tail-length, 8.4 mm., 62 per cent of total length. Snout, in dorsal view, bluntly rounded; in lateral view less bluntly rounded; body depressed; head flattened; mouth terminal; eye large, its diameter 25 per cent of length of body; nostrils near tip of snout and directed anteriorly; spiracle sinistral and situated postero-ventrad to eye; cloaca median. Tail-fin thrice depth of tail-musculature, which extends beyond posterior end of tail-fin giving sword-tail appearance (Fig. 2). In life, black stripe on each side of body and on top of head; black band on anterior part of tail and another on the posterior part; body and anterior part of tail creamy yellow; dark red band between black bands on tail. Mouth terminal, small, its width about one-fifth width of body; fleshy ridge dorsally and ventrally; row of small papillae on ventral lip; no lateral indentations of lips; upper beak massive, convex, and finely serrate; lower beak small and mostly concealed behind upper; no teeth (Fig. 3). [Illustration: FIG. 3. Mouthparts of larval _Hyla ebraccata_ (KU 59986) from Toocog, El Petén, Guatemala. × 100.] =Hyla loquax= Gaige and Stuart Toocog, 14. These specimens were found at night when they were calling from low vegetation in a forest pond. Most of the frogs were several meters away from the edge of the pond. Although two clasping pairs were found, we obtained no eggs or tadpoles referable to this species. =Hyla microcephala martini= Smith Chinajá, 1; Toocog, 21. The specimen from Chinajá was calling from a small bush at the edge of a temporary grassy pond in a clearing in the forest. At Toocog this species was closely associated with _Hyla ebraccata_; males were calling from herbaceous vegetation in and around the forest pond. These frogs were not so abundant in the forest at Toocog as they were around ponds on the savanna at La Libertad. =Hyla picta= (Günther) Toocog, 8. This small tree frog was calling from herbs in a pond in the forest on June 30 and July 2. The voice is weak; probably greater numbers of males were present than are indicated by the few specimens collected, for the din from the more vociferous species made it impossible to hear _Hyla picta_ unless one was calling close by. =Hyla staufferi= Cope Chinajá, 1. This individual was calling from a low bush in the clearing at Chinajá. None was found in the pond in the forest at Toocog. Stuart (1935:38) and Duellman (1960:63) noted that _Hyla staufferi_ breeds early in the rainy season. Nevertheless, I think early breeding habits do not account for the near absence of this species in our collections from southern El Petén. In early July, 1960, a few individuals were heard at a pond on the savanna at La Libertad. In mid-July of the same year they were calling sporadically from temporary ponds in the lower Motagua Valley. Possibly the individual collected at Chinajá was accidentally transported there in cargo from Toocog, from which camp at the edge of the savanna planes fly to Chinajá weekly. My observations on this species throughout its range in México and Central America indicate that it inhabits savannas and semi-arid forests and usually is absent from heavy rainforest. Stuart (1948:34) obtained this species at Cubilquitz in the lowlands of Alta Verapaz. =Phyllomedusa callidryas taylori= Funkhouser Toocog, 25. Between June 30 and July 2 this species was abundant at a pond in the forest at Toocog. Calling males were as high as five meters in bushes and trees around the pond. At dusk males were observed descending a vine-covered tree at the edge of the pond; this strongly suggests that the frogs retreat to this tree and others like it for diurnal seclusion. Clasping pairs were found on branches and leaves above the water. The eggs are deposited in clumps usually on vertical leaves, but sometimes on horizontal leaves or on branches, vines, and aerial roots above the water. Twenty-six clutches of eggs contained from 14 to 44 (average 29) eggs. In a clutch in which the eggs are in yolk plug stage the average diameter of the embryos is 2.3 mm. and that of the vitelline membranes, 3.4 mm. Most of the eggs are in the external part of the gelatinous mass; the jelly is clear. The yolk is pale green, and the animal pole is brown. As development ensues, the yolk becomes yellow and the embryo first dark brown and then pale grayish tan. Upon hatching the tadpoles wriggle free of the jelly and drop into the water. One clutch of 19 eggs was observed to hatch in three minutes. Apparently, on dropping into the water the hatchling tadpoles go to the bottom of the pond, for one or two minutes pass from the time they enter the water until they reappear near the surface. The average total length of seven hatchling tadpoles is 7.4 mm. There is a moderate amount of yolk, but this does not form a large ventral bulge. Large tadpoles congregate in the sunny parts of the pond, where they were observed just beneath the surface. Many had their mouths at the surface. Except for constant fluttering of the tip of the tail, they lie quietly with the axis of the body at an angle of about 45 degrees with the surface of the water. Description of tadpole (KU 60006): total length, 24.5 mm.; tail-length, 15.4 mm.; body broader than deep; head moderately flattened; snout viewed from above blunt; nostrils close to snout and directed dorsally; eyes of moderate size and directed laterally; mouth directed anteroventrally; anus median; spiracle ventral, its opening just to left of midline slightly more than one-half distance from tip of snout to vent. Tail-fin slightly more than twice as deep as tail musculature, which curves upward posteriorly; tail-fin narrowly extending to tip of tail (Fig. 4). Color in life pale gray; in preservative white with scattered melanophores; tail-fin transparent. [Illustration: FIG. 4. Tadpole of _Phyllomedusa callidryas taylori_ (KU 60006) from Toocog, El Petén, Guatemala. × 4.] Upper lip having single row of papillae laterally, but none medially; lower lip having single row of papillae; no lateral indentation of lips; two or more rows of papillae at lateral corners of lips; tooth-rows 2/3; second upper tooth row as long as first, interrupted medially; inner lower tooth-row as long as upper rows, interrupted medially; second and third lower rows decreasingly shorter; upper beak moderate in size and having long lateral projections; lower beak moderate in size; both beaks finely serrate (Fig. 5). [Illustration: FIG. 5. Mouthparts of larval _Phyllomedusa callidryas taylori_ (KU 60006) from Toocog, El Petén, Guatemala. × 30.] =Smilisca baudini= (Duméril and Bibron) Chinajá, 9; 20 km. NNW of Chinajá, 42; Río de la Pasión, 1; Río San Román, 5; Sayaxché; Toocog, 2. Individuals of this species were found at night sitting on bushes and small trees in the forest in February and March and again in June and July. One was in the axil of a leaf of a _Xanthosoma_. In June and July males were heard nearly every night. The series of specimens from 20 kilometers north-northwest of Chinajá was taken from a breeding congregation in a shallow muddy pool in the forest. Tadpoles of this species were in small, often muddy pools in the forest. To my knowledge _Smilisca baudini_ is the only hylid to breed in these pools at Chinajá, although perhaps _Smilisca phaeota_ also utilizes them. The only other amphibian at Chinajá known to breed in the pools is _Bufo valliceps valliceps_. Although two specimens were on bushes at night at Toocog, _Smilisca baudini_ was not present at the pond where five other species of hylids were breeding. Nevertheless, _Smilisca baudini_ was calling from two ponds on the savannas near La Libertad. All of the specimens from southern El Petén have yellow or yellowish white flanks and ventrolateral surfaces. =Smilisca phaeota cyanosticta= (Smith) Chinajá, 4; 10 km. NNW of Chinajá, 1. All specimens were found in February and March. Those from Chinajá were obtained from _Xanthosoma_ and bromeliads; the individual from 10 kilometers north-northwest of Chinajá is an adult male that was calling from a puddle in a fallen tree on March 13. A juvenile having a snout-vent length of 34.7 mm. lacks the pale blue spots on the thighs; instead, the anterior and posterior surfaces of the thighs are bright red. =Hypopachus cuneus nigroreticulatus= Taylor Toocog, 1. An adult male having a snout-vent length of 41.7 mm. was found at night on the forest floor at the edge of a temporary pond. In life the dorsum was dark brown with chocolate brown markings; the stripe on the side of the head was white; the middorsal stripe was pale orange; the belly was black and white, and the iris was a bronze color. Characteristically this species inhabits savannas and open forest; thus, its occurrence in the rainforest at Toocog is surprising. This is the southernmost record for the species in El Petén; to the south in the highlands it is replaced by the smaller _Hypopachus inguinalis_, having rounded, instead of compressed, metatarsal tubercles. =Rana palmipes= Spix Chinajá, 11; 15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 1. With the exception of one recently metamorphosed juvenile having a snout-vent length of 30.7 mm. that was found on the forest floor by day on June 24, and one that was found beside a pool in a cave, all individuals were found at temporary woodland pools or along sluggish streams at night. The largest specimen is a female having a snout-vent length of 107 mm. =Rana pipiens= Schreber Chinajá, 1; 20 km. NNW of Chinajá, 1; Río San Román, 1; Toocog, 1. All specimens were found near water at night. The largest individual is a female having a snout-vent length of 112.5 mm. =Crocodylus moreleti= Duméril and Duméril Chinajá, 1; Río San Román, 1. One specimen was obtained from a quiet pool in the Río San Román at night; another was found in a small sluggish stream at Chinajá. Two large individuals were seen in tributaries to the Río San Román. On the savannas at Toocog two small individuals were obtained in the dry season, at which time the crocodiles apparently were migrating to water. The local name for this species is _lagarto_. =Chelydra rossignoni= (Bocourt) Chinajá, 1; 20 km. NNW of Chinajá, 1. The paucity of specimens of _Chelydra_ from Central America has resulted in rather inadequate diagnoses of various populations. The present specimens have carapace lengths of 250 and 238 mm. and plastral lengths of 185 and 176 mm. The length of carapace/bridge ratio is 6.0 and 6.1 per cent. Each individual has four barbels, the median pair of which are extremely long. In KU 55977 the lateral pair of barbels is forked at the base. The relative length of the plastral bridge in these specimens compares favorable with the ratio (.06-.08) given by Schmidt (1946:4) for five specimens from Honduras. _Chelydra serpentina_, which may occur sympatrically with _C. rossignoni_ in some parts of Central America, has a narrower plastral bridge and only two barbels beneath the chin. Furthermore, _C. rossignoni_ and _C. osceola_ in Florida have long, flat tubercles on the dorsal and lateral surfaces of the neck, whereas _C. serpentina_ has short, round tubercles. The specimen from Chinajá was found in a small sluggish stream; the other individual was in a muddy pool in the forest. The local name is _sambodanga_. =Claudius angustatus= Cope 20 km. NNW of Chinajá, 1. One specimen was unearthed from the bank of a small muddy stream by a bulldozer. This individual represents the second record for the species in Guatemala; the first was provided by specimens, likewise found in muddy waters, at Tikal (Stuart, 1958:19). The local name is _caiman_. =Kinosternon acutum= Gray 20 km. NNW of Chinajá, 4; 30 km. NNW of Chinajá, 2. These turtles were found on the forest floor, in small sluggish streams, and in pools in the forest. One adult male had, in life, the top of the head yellow with black spots; the stripes on the head and neck were red. Specimens were obtained both in the dry and rainy seasons. The local name for both species of _Kinosternon_ is _pochitoque_. =Kinosternon leucostomum= Duméril and Bibron Chinajá, 3; 15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 2. Individuals of this turtle were found on the forest floor and in small sluggish streams. In life most specimens had a tan or pale brown head with pinkish tan stripes on the head and neck. All individuals were obtained in February and March. No ecological differences between this species and _K. acutum_ were evident. =Staurotypus triporcatus= (Wiegmann) Paso Subín, 1. This species is represented in the collection by one complete shell found on the bank of the Río Subín. The carapace has a length of 292 mm. The local name is _Guao_. Natives stated that this turtle was not uncommon in clear rivers and lakes, a habitat suggested for the species by Stuart (1958:19). =Dermatemys mawi= Gray Chinajá, 1; Río San Román, 4. The record from Chinajá is based on a carapace found in a chiclero camp, where the turtle evidently had been brought for food. The four specimens from the Río San Román were obtained from edges of deep pools in clear water. In adult males the top of the head was reddish orange in life. One of the specimens from the Río San Román currently is living in the Philadelphia Zoological Gardens. The local name for this turtle is _tortuga blanca_; it is sought for its meat. =Geoemyda areolata= (Duméril and Bibron) Chinajá, 2. Two specimens were obtained from dense forest at Chinajá. The local name is _mojina_. =Pseudemys scripta ornata= (Gray) Paso Subín, 1. One subadult was obtained from clear water in the Río Subín. The stripes on the head and neck were yellow; there was no red "ear" on the side of the head. The stripes on the forelimbs were orange, and the ocelli on the carapace were red. The local name is _jicotea_. =Coleonyx elegans elegans= Gray Toocog, 1. One adult male having a snout-vent length of 89 mm. was found beneath a log in the forest. Locally this gecko is known as _escorpión_; the natives believe it to be deadly poisonous. The use of the name _escorpión_ seems to be restricted to lizards thought to be venomous. Nearly everywhere in México and Central America some species of lizard carries this appellation. In El Petén I heard the name used only for _Coleonyx elegans_ and _Thecadactylus rapicaudus_; in the lowlands of Guerrero, México, the name is applied to geckos of the genus _Phyllodactylus_. The venomous lizards of the genus _Heloderma_ in the lowlands of western México are called _escorpiónes_. In the mountains of southern México various skinks of the genus _Eumeces_, as well as lizards of the genus _Xenosaurus_, carry the same appellation. _Abronia_ in the mountains of México and _Gerrhonontus_ throughout México and Central America likewise are called _escorpiónes_. Although many people in various parts of Middle America consider most lizards poisonous, there is a unanimity of opinion concerning the venomous qualities of the various kinds of _escorpiónes_. I know of only two other lizards in Middle America that are so uniformly regarded in native beliefs; these are _Enyaliosaurus clarki_ in the Tepalcatepec Valley in Michoacán, called _nopiche_, and _Phrynosoma asio_ in western México, called _cameleón_. =Sphaerodactylus lineolatus= Lichtenstein 15 km. NW of Chinajá, 1; Toocog, 1. These small geckos were much more abundant than the few specimens indicate. They frequently were seen on the trunks of corozo palms, where they quickly took refuge in crevices at the bases of the fronds. The specimen obtained at Toocog was under the bark of a standing dead tree. In life the ventral surface of the tail was orange. The individual from Chinajá was in the leaf litter on the ground at the base of a dead tree. =Thecadactylus rapicaudus= (Houttuyn) 15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 2. Two specimens were found beneath the bark of standing dead trees; another was found in the crack in the trunk of a mahogany tree about 13 meters above the ground. In life the dorsum was yellowish tan with dark brown markings; the venter was yellowish tan with brown flecks, and the iris was olive-tan. The largest specimen is a male having a snout-vent length of 95 mm.; all specimens have regenerated tails. Individuals when caught twisted their bodies and attempted to bite; upon grabbing a finger they held on with great tenacity. =Anolis biporcatus= (Wiegmann) 14 km. NNW of Chinajá, 1; 17 km. NNW of Chinajá, 1; 20 km. NNW of Chinajá, 3; 30 km. NNW of Chinajá, 1; Sayaxché, 1. All specimens of this large anole were obtained from trees. Some individuals were found in the tops of trees immediately after they were felled. My limited observations on this anole suggest that it is an inhabitant of the upper levels of the forest. In life an adult male from 20 kilometers north-northwest of Chinajá was brilliant green above; the eyelids were bright yellow; the belly was white. The outer part of the dewlap was pale orange, and the median part was pinkish blue. A juvenile having a snout-vent length of 47 mm. and a tail length of 86 mm. was pale grayish green with pale gray flecks on the dorsum. The largest male has a snout-vent length of 98 mm. and a tail length of 217 mm.; the same measurements of the largest female are 89 and 213 mm. This species, together with all other anoles, is known locally as _toloque_. =Anolis capito= Peters Chinajá, 2; 14 km. NNW of Chinajá, 1; Río de la Pasión, 1. All individuals were observed on trunks of trees between heights of three and ten meters above the ground. The largest male has a snout-vent length of 81 mm. and a tail length of 155 mm.; the same measurements of the largest female are 87 and 150 mm. The streaked brown dorsum, combined with the lizards' habit of pressing the body against the trunks of trees, make this anole especially difficult to see. =Anolis humilis uniformis= Cope Chinajá, 24; 15 km. NW of Chinajá, 22; 20 km. NNW of Chinajá, 6; Sayaxché, 1. This small dull brown anole is a characteristic inhabitant of the forest floor, where the lizards move about in a series of quick, short hops and thus easily evade capture. Three individuals were found on small bushes, and four were on the bases of trees; otherwise, all were observed on the ground. Observations indicate that this species is active throughout the day, except during and immediately after heavy rains. The males have a deep red dewlap with a dark blue median spot. =Anolis lemurinus bourgeaei= Bocourt Chinajá, 11; 20 km. NNW of Chinajá, 4; 30 km. NNW of Chinajá, 2; Río de la Pasión, 1; Río San Román, 1; Sayaxché, 8; Toocog, 6. This moderate-sized anole characteristically inhabits the low bushes and bases of trees in the forest. Individuals were most readily observed on the buttresses of some of the gigantic mahogany and ceiba trees. When approached the lizards usually ran around the tree or ducked to the other side of the buttress; if the observer moved closer, they jumped to the ground and ran off. None was observed to ascend large trees. Some individuals were observed foraging on the forest floor; these took shelter on the bases of trees. One individual was sleeping on a palm frond at night. The adult males have a uniformly orange-red dewlap. =Anolis limifrons rodriguezi= Bocourt 15 km. NW of Chinajá, 2; 20 km. NNW of Chinajá, 1. In dry forests and more open situations than occur at Chinajá this little anole is abundant, but in the wet forests of southern El Petén, only three specimens were found. Two were on palm fronds about two meters above the ground; the other was on a low bush. I suspect that ecologically this species overlaps _A. humilis uniformis_ and _A. lemurinus bourgeaei_, but too few observations are recorded to justify a definite statement at this time. =Anolis sericeus sericeus= Hallowell Chinajá, 2; Sayaxché, 1; Toocog, 1. This small anole is common and widespread in the Atlantic lowlands of southern México and northern Central America; usually it inhabits sub-humid regions. Consequently, its presence in the wet forests of southern El Petén was unexpected. The specimens from Chinajá were sleeping on low bushes at night, whereas the others were found on bushes by day. =Basiliscus vittatus= Wiegmann Chinajá, 6; Río de la Pasión, 1; Río San Román, 1; Sayaxché, 3; Toocog, 1. Individuals of this abundant species were most frequently seen in dense bushes along the margins of rivers or small streams. None was observed far from water. These lizards, like the anoles, are known locally as _toloque_. =Corythophanes cristatus= (Merrem) Chinajá, 3; 20 km. NNW of Chinajá, 1. Three individuals were found on tree trunks; the fourth was on a thick vine about one meter above the ground. The two largest males have snout-vent lengths of 121 and 115 mm. and tail lengths of 265 and 243 mm. The largest female (KU 59603), obtained on June 28, has a snout-vent length of 125 mm. and a tail length of 247 mm. This individual contained eight ova varying in greatest diameter from 10.6 to 12.2 (average 11.1) mm. Also present are numerous ovarian eggs having diameters up to about 3.5 mm. One of the large males displayed a defensive behavior prior to capture. When first observed the lizard was clinging to a tree trunk about one and one-half meters above the ground. When I approached, the lizard turned its flanks towards me; then it flattened the body laterally, extended the dewlap, opened its mouth, and made short rushing motions. When touched it bit viciously. On the ground these lizards have a rather awkward bipedal gait that is much slower than in _Basiliscus vittatus_. In life an adult male (KU 55804) was reddish brown dorsally with dark chocolate brown markings; the venter was creamy white, and the iris was dark red. The natives call this lizard _piende jente_. =Iguana iguana rhinolopha= Wiegmann Río San Román, 2. The _iguana_, as this lizard is called locally, seems to be uncommon in the forested areas of southern El Petén. Possibly this is due to the fact that the flesh of this lizard is relished as food by the natives. My two specimens were in large trees at the edge of the river. =Laemanctus deborrei= Boulenger Chinajá, 1; Toocog, 5. On June 26 a female having a snout-vent length of 129 mm. and a tail length of 502 mm. was found on a bush in the forest. The lizard, when approached, faced the collector and opened its mouth. In life the dorsum was bright green; the lateral stripe was white, and the iris was yellowish brown. This specimen contained four ova having lengths of 13.4 to 14.2 (average 13.9) mm. On June 30 at Toocog five white-shelled eggs were found in a rotting log. Measurements of the eggs are--length, 23.5 to 25.0 (average 24.2) mm.; width, 15.0 to 15.5 (average 15.4) mm. These eggs hatched on August 30. The five young had snout-vent lengths of 43 to 45 (average 44) mm., and tail lengths of 137 to 140 (average 138) mm. In life the hatchlings had a dull dark green dorsum, pale bright green venter and stripes on head, and reddish brown iris. In preservative the hatchlings are creamy tan above with five or six square dark brown blotches middorsally. The natives consider this lizard to be one of the anoles; consequently, it is known as _toloque_. =Lepidophyma flavimaculatum flavimaculatum= Duméril Chinajá, 8; 15 km. NW of Chinajá, 2. Individuals were found beneath logs on the forest floor or moving about in the litter on the forest floor. One was observed crawling across a trail during a heavy rain. In some adults the tan dorsal spots are large and distinct; in others the spots are small and indistinct. Two juveniles, apparently recent hatchlings, were found on June 28 and July 5. These specimens have snout-vent lengths of 29 mm. and tail lengths of 38 and 41 mm. =Eumeces schwartzei= Fischer Chinajá, 1. One specimen (KU 59551) was found on the forest floor at midday; it is an adult female having a snout-vent length of 125 mm. and a tail length of 210 mm. This specimen is larger than those recorded by Taylor (1936:99) and extends the known range of the species south of Ramate, approximately 125 kilometers south-south-westward to Chinajá. =Eumeces sumichrasti= (Cope) 20 km. NNW of Chinajá, 1. One adult male having a snout-vent length of 82 mm. was found beneath a palm frond on the forest floor. In life the dorsum was dull brown; the chin was cream; the belly was yellow, and the underside of the tail was orange. A juvenile having a black body, yellow dorsal stripes, and a bright blue tail was observed on the forest floor. =Scincella cherriei cherriei= (Cope) Chinajá, 2; 30 km. NNW of Chinajá, 1; Toocog, 1. All individuals of this lizard were found in the leaf litter on the forest floor; many escaped capture. In life the tail is dull bluish gray. The number of dorsal scales varies from 59 to 61 (average 60); thus, these specimens fall within the range of variation of _S. cherriei cherriei_, and thereby differ from _S. cherriei stuarti_ to the west and _S. cherriei ixbaac_ to the north. =Ameiva festiva edwardsi= Bocourt Chinajá, 16; 15 km. NW of Chinajá, 10; Sayaché, 4; Toocog, 1. This abundant terrestrial lizard, locally called _lagartijo_, is found throughout the forest. A juvenile obtained on March 14 at Sayaxché has a snout-vent length of 42 mm. and a prominent umbilical scar. Other juveniles were observed at Chinajá in February and March, thereby indicating that the young probably hatch in the early part of the year. Juveniles have bright blue tails. =Celestus rozellae= Smith 20 km. NNW of Chinajá, 2. Two specimens were obtained from trees by workmen in February. These lizards have snout-vent lengths of 70 and 83 mm. and tail lengths of 133 and 135 mm. There are 21 and 23 lamellae beneath the fourth toe; each has 31 longitudinal rows of scales around the body. =Boa constrictor imperator= Daudin 15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 2; Toocog, 1. All specimens were found on the forest floor. One individual was found in combat with a large _Drymarchon corais melanurus_. Apparently, the _Drymarchon_ was attempting to devour the _Boa_, which had a total length of 1683 mm. Locally this snake is called _masacuata_; it is one of the few snakes believed by the local inhabitants to be non-poisonous. =Clelia clelia clelia= Daudin 15 km. NW of Chinajá, 1; 20 km. NNW of Chinajá, 1. One specimen is represented only by the head; the snake was killed on the forest floor by workmen. Another individual was found in a pool of water at the base of a limestone outcropping in the forest; this specimen (KU 58167) is a female having a body length of 2220 mm. and a total length of 2634 mm. This snake contained 22 ova averaging 56 × 23 mm. Both specimens were uniform shiny black above and cream-color below. The local name is _sumbadora_. =Coniophanes bipunctatus bipunctatus= (Günther) Chinajá, 1. This snake was found on the forest floor by day; it is a male having 130 ventrals, an incomplete tail; cream-colored belly, and a pair of large brown spots on each ventral scute. =Coniophanes fissidens fissidens= (Günther) Toocog, 1. This male specimen was found beneath a rock in a sink hole. It has 122 ventrals and 77 caudals. A narrow temporal stripe extends along the upper edge of the anterior temporal and the lower edge of the upper secondary temporal. The belly is ashy white with a pair of small black spots on each ventral. =Coniophanes imperialis clavatus= (Peters) Chinajá, 3. All specimens were found on the forest floor by day. These small snakes are capable of rapid movement and quickly disappear in the litter on the ground. Two individuals evaded capture. The belly is creamy white anteriorly and vermillion red posteriorly. =Dryadophis melanolomus laevis= (Fischer) Chinajá, 3. These snakes, locally known as _sumbadora_, were found on the forest floor; two others were seen, but escaped. The variation in coloration has been a source of confusion in this species in northern Central America (see Stuart, 1941:86). All of the present specimens are males: KU 55709 has 178 ventrals, 121 caudals, and a total length of 914 mm.; the dorsum is olive-tan with six darker cross-bars on the neck; the belly is creamy white. KU 58160 has 188 ventrals, 123 caudals, and a total length of 1365 mm.; the dorsum is uniform olive-brown, except that some dorsal scales at midbody have black anterior borders like _D. melanolomus melanolomus_ has in the Yucatán Peninsula; the venter is pale yellow. KU 58158 has 179 ventrals, 122 caudals, and a total length of 723 mm.; the dorsum is rich chocolate brown with eight dark cross-bars on the neck; the belly is bright orange. Stuart (1941a:87) stated that in life two distinct color phases were observed in specimens collected by him in Alta Verapaz, Guatemala. One had an olive-brown dorsum and the other, a reddish orange dorsum. Stuart made no mention of variation in the color of the venter. Similar variation is known in _D. melanolomus alternatus_ in Costa Rica, where some individuals have orange-red venters. This color phase has been recognized as a distinct species, _Dryadophis sanguiventris_, by Taylor (1954:722). Examination of 18 specimens from Costa Rica shows no differences in scutellation, nor geographic segregation of two populations. I am convinced that the red-bellied _Dryadophis_ in Costa Rica, like those in Guatemala, represent a color phase of the subspecies inhabiting those areas and that _Dryadophis sanguiventris_ Taylor is a synonym of _Dryadophis melanolomus alternatus_ (Bocourt). =Drymarchon corais melanurus= (Duméril, Bibron and Duméril) 15 km. NW of Chinajá, 1; Sayaxché, 1. The specimen from Sayaxché was found at the edge of a clearing in the forest; that from 15 kilometers northwest of Chinajá was found on the forest floor coiled with a _Boa constrictor imperator_, which the _Drymarchon_ apparently was trying to eat. The _Drymarchon_ is a giant specimen having a total length of 2950 mm. (see Duellman, 1961:368). The _Boa_ with which it was coiled has a total length of 1683 mm. I was attracted to the snakes by a loud thrashing noise. When I approached the writhing mass, the snakes separated, but I was able to see that the _Drymarchon_ had its teeth firmly imbedded in the posterior part of the head of the _Boa_. From the _Drymarchon_ I forced the regurgitation of a recently ingested _Bothrops nummifer nummifer_ having a total length of 953 mm. These observations show that the snake-eating capabilities of _Drymarchon_ can hardly be over-estimated. In both _Drymarchon_ the anterior one-half of the body is olive-tan, which changes to bluish black posteriorly. The local name is _sumbadora_. =Drymobius margaritiferus margaritiferus= (Schlegel) Chinajá, 3; Sayaxché, 1. All individuals were obtained in clearings in the forest by day in the rainy season. Two individuals each contained a _Similisca baudini_ and another contained a _Bufo valliceps valliceps_. Locally this snake is known by the appropriate name of _ranera_. =Imantodes cenchoa leucomelas= Cope Chinajá, 4. With the exception of one that was found dead in camp, all individuals were taken from low vegetation by day. The dorsum is creamy tan with 28 to 35 (average 32) chocolate brown blotches, and the venter is ashy white with small brown flecks. Three males have 238 to 248 (average 244) ventrals and 148 to 154 (average 151) caudals; one female has 239 ventrals and 142 caudals. The largest specimen, a male, has a body length of 660 mm. and a total length of 943 mm. =Lampropeltis doliata polyzona= Cope Chinajá, 1. One female (KU 57156) having 230 ventrals and 54 caudals was found on the forest floor by day. This individual has a black snout with a white bar across the nasals and prefrontals, a white spot in the middle of the frontal, and a white band across the temporals and parietals that is bordered posteriorly by a black band. There are 28 white and 28 red rings on the body. The tips of the red scales are darkened. The black rings between the white and red rings are not so expanded as to interrupt the white rings dorsally as in _L. doliata abnorma_ as identified by Stuart (1948:70). Locally this snake, like all red, black, and white or yellow banded snakes, is called _coral_ or _coralillo_. =Leptodeira frenata malleisi= Dunn and Stuart Toocog, 1. This specimen, a male having 173 ventrals and 69 caudals, was found beneath the bark on a log in the forest. In life the dorsum was pinkish tan with 36 chocolate brown blotches on the body; the venter was rosy pink. =Leptodeira septentrionalis polysticta= Günther Chinajá, 3; Toocog, 11. If numbers of specimens are indicative of abundance, this is the most common snake in southern El Petén. All were found at night in the rainy season. At a pond in the forest at Toocog these snakes were observed on low vegetation, on the ground, and in the water. Evidently they congregate at breeding choruses of frogs. One _Leptodeira_ contained a _Smilisca baudini_ and another contained eggs of _Phyllomedusa callidryas taylori_. The natives call this snake _nahuyaca_. =Leptophis ahaetulla praestans= (Cope) 13 km. NNW of Chinajá, 1; 20 km. NNW of Chinajá, 1. Both specimens were obtained from trees when they were felled. One individual (KU 55716) has a body length of 1345 mm. and a total length of 2035 mm. In life the entire snake was uniform bright green; the eye was yellow. In preservative the dorsum is dark blue, and the venter is green. =Leptophis mexicanus mexicanus= Duméril, Bibron and Duméril Chinajá, 1; 15 km. NW of Chinajá, 1; Sayaxché, 4. All specimens came from low trees in the forest. The largest specimen is a male having a body length of 724 mm. and a total length of 1236 mm. In life the middorsum was a golden tan; the top of the head was a vivid green. One individual had ingested a _Smilisca baudini_. The local name is _bejuquillo_. =Ninia sebae sebae= (Duméril, Bibron and Duméril) Toocog, 1. This specimen, a male having 144 ventrals and 55 caudals, was found beneath bark on a log in the forest. There is a black band five scales in length on the nape followed posteriorly by a red band six scales in length and then by a complete black band one and one-half scales in length. The rest of the body is dull red with 16 incomplete black bands one to one and one-half scales in length on the anterior two-thirds of the body. =Oxybelis aeneus aeneus= (Wagler) Chinajá, 1; 20 km. NNW of Chinajá, 1. One individual was found in a low tree; the other was in a bush. Both specimens are males; the largest has a body length of 754 mm. and a total length of 1286 mm. Bogert and Oliver (1945:388) distinguished _O. aeneus aeneus_ in Central and South America from _O. aeneus auratus_ in México in that the diameter of the eye is more than the length of the internasal, whereas in _O. aeneus auratus_ the diameter of the eye is less than the length of the internasal. Stuart (1958:27) stated that on the basis of this character three specimens from Tikal in northeastern El Petén definitely were _O. aeneus aeneus_. Of the present specimens from southern El Petén, one has an internasal:eye ratio of 1.08; the other has a ratio of 0.87. A careful review of these snakes is needed to verify the validity of the characters used to separate the subspecies and to determine areas of intergradation. The local name for the vine-snake is _bejuquillo_. =Pliocercus euryzonus aequalis= Salvin Chinajá, 1; Río San Román, 1. These specimens are tentatively referred to _P. euryzonus_. KU 57160 is a female having 130 ventrals, 87 caudals, and 23 black rings on the body; KU 58150 is a juvenile having 128 ventrals, 79 caudals, and 27 black rings on the body. In both specimens the tip of the snout is yellow; a broad yellow band on the parietals and temporals is bordered posteriorly by a black band on the nape. The black rings on the body are not bordered by yellow, but black rings on the tail have yellow borders ventrally. In the red interspaces between the black rings, black flecks and spots, especially posteriorly, tend to form secondary black rings (Fig. 6a). According to Stuart (1948:71), _P. euryzonus aequalis_ has 25 to 27 black rings on the body, whereas _P. elapoides salvini_, which also occurs in El Petén, has 15 to 23 black rings. [Illustration: FIG. 6. Dorsal color patterns of _Pliocercus euryzonus aequalis_ (A) and _Micrurus affinis apiatus_ (B).] The specimen from the Río San Román contained a partly digested _Bolitoglossa moreleti mulleri_. Locally _Piocercus_ is called _coral_ or _coralillo_. =Pseustes poecilonotus poecilonotus= (Günther) Chinajá, 3; 20 km. NNW of Chinajá, 1. Two juveniles were on the forest floor; one juvenile and an adult were on low bushes. The juveniles have a tan dorsum with reddish brown blotches; the belly is gray, and the iris is cream-color above and brown below. The one adult is olive-brown above and creamy white below on the anterior three-fourths of the body; posteriorly it is black above and below. There are no paravertebral dark stripes nor pale spots on the dorsal scales. Two specimens (one juvenile and the adult) when encountered compressed the anterior part of the body laterally and struck repeatedly. Locally the adults are called _sumbadora_. =Sibon dimidiata dimidiata= (Günther) 20 km. NNW of Chinajá, 2. Both snakes were obtained from trees when they were felled. In life the dorsum was pinkish orange with dark chocolate brown blotches narrowly edged with black. =Sibon nebulata nebulata= (Linnaeus) 20 km. NW of Chinajá, 1. This specimen, a male having a body length of 544 mm. and a tail length of 198 mm., was found in a felled tree. In life the belly was pink and black; the dorsal black blotches were narrowly outlined with pink. =Spilotes pullatus mexicanus= (Laurenti) Chinajá, 3; 20 km. NNW of Chinajá, 1; Sayaxché, 1. This large snake, locally called _mica_, seems to be equally at home on the ground and in low trees and bushes. It is fast moving for a large snake; two individuals escaped capture. The natives said that this snake eats other snakes, but examination of stomachs revealed no supporting evidence. =Stenorrhina degenhardti= (Berthold) Chinajá, 1. This specimen, a female having 158 ventrals, 37 caudals, and a total length of 489 mm., was found on the forest floor. On the olive-brown dorsum are 27 irregular, narrow, dark brown, transverse bands. The head is uniform olive-brown; the chin and labials are cream-color. The venter is cream-color with a row of brown spots forming a midventral stripe. A large spider was found in the stomach. I have refrained from assigning a subspecific name to this snake. Cursory examination of specimens from throughout México and Central America reveals a bewildering array of variation in coloration that suggests that the subspecies _mexicanus_ is not recognizable, or that two species occur sympatrically in parts of southern México and northern Central America. =Tretanorhinus nigroluteus lateralis= Bocourt Chinajá, 1. A single male having 136 ventrals, 75 caudals, and a total length of 407 mm. was found by a stream in camp. The dorsum is pale grayish tan with 34 pairs of small chocolate brown spots, some of the anterior ones of which are connected across the back. A cream-colored lateral stripe is on the third and fourth dorsal scale-rows anteriorly and the second and third rows posteriorly. The lower dorsal scale rows are black. The venter is dark grayish brown with cream-colored flecks anteriorly and creamy gray posteriorly where the dark color is restricted to the midventral region and the lateral edges of ventrals and first dorsal scale-row. =Xenodon rabdocephalus mexicanus= Smith Chinajá, 1; 20 km. NNW of Chinajá, 1. Both individuals were found on the forest floor. An adult male having a total length of 420 mm. has a cream-colored venter with brown flecks. A juvenile having a total length of 172 mm. has a creamy white belly with black crossbands. At the suggestion of L. C. Stuart, I am following Schmidt (1941:501) in placing _X. mexicanus_ as a subspecies of _X. rabdocephalus_. =Micrurus affinis apiatus= (Jan) 20 km. NNW of Chinajá, 2; Sayaxché, 1. All specimens were found beneath litter on the forest floor. All are males having 202 to 211 (average 205) ventrals, 53 to 56 (54.6) caudals, and 34 to 48 (41) primary black rings on the body. There are no yellow rings, and black spots in the red interspaces tend to form secondary black rings (Fig. 6b), the same as in _Pliocercus euryzonus aequalis_. The local name is _coral_ or _coralillo_. =Bothrops atrox asper= (Garman) 15 km. NW of Chinajá, 1; Sayaxché, 1. Although we found only two specimens, natives and workmen at the camp at Chinajá stated that the _barba amarilla_, as this snake is known locally, had been abundant when the camp had been established less than two years before our visit. =Bothrops nasutus= Bocourt 12 km. NW of Chinajá, 1. This specimen, a male having a total length of 415 mm., was found on the forest floor. The dorsum is brown with dark brown blotches separated middorsally by a narrow orange-tan stripe extending from the nape to the base of the tail. The belly is grayish tan with white flecks on the lateral edges of the ventrals. The local name is _nahuyaca_. =Bothrops nummifer nummifer= (Rüppell) 15 km. NW of Chinajá, 2; Sayaxché, 1. Two individuals were found on the forest floor, and one adult, having a total length of 953 mm., was removed from the stomach of a large _Drymarchon corais melanurus_. There is considerable variation in color and pattern. A juvenile (KU 58104), having a total length of 332 mm., has a tan dorsum with 19 interconnected dark brown, diamond-shaped, middorsal blotches, the lateral extensions of which are black; the belly is a cream-color with brown squares. An adult female (KU 55706), having a total length of 779 mm., has a dorsal coloration like the preceding specimen, except that the lateral extensions of the dorsal blotches are brown; the belly is a uniform cream-color. A second adult female (KU 55707), having a total length of 953 mm., has a brown dorsum with 21 interconnected black, diamond-shaped, middorsal blotches, the lateral extensions of which are black; the belly is a cream-color with black squares. The local name for this species is _braza de piedra_. =Bothrops schlegeli schlegeli= (Berthold) Paso Subín, 1. This specimen was taken from the thatched roof of a house at the edge of the forest and contained the remains of a small mammal. The local name is _nahuyaca_. HYPOTHETICAL LIST OF SPECIES Listed below are thirteen species that have not been found in southern El Petén but that probably occur there. =_Dermophis mexicanus mexicanus_= (Duméril and Bibron).--Natives at Chinajá know caecilians, which they call _dos cabezas_. This species has been taken in Tabasco and northern Chiapas. Its occurrence in southern El Petén is expected. Less likely, the caecilian known to the natives at Chinajá is _Gymnopis oligozona_, which is known from Finca Volcán on the southern slopes of the valley of the Río Cahabón in Alta Verapaz. =_Gastrophryne elegans_= (Boulenger).--This small fossorial frog is known from Piedras Negras (Taylor and Smith, 1945:604), 12 miles east of Yaxha (Stuart, 1934:7), and Tikal (Stuart, 1958:18), all in northern and central El Petén. Two specimens in the collection of the University of Kansas are from 28 kilometers northeast of Campur, Alta Verapaz. Probably the species ranges throughout the forested lowlands of northern Alta Verapaz and El Petén. =_Mabuya brachypoda_= Taylor.--The absence of this widespread lizard in our collections cannot be explained. Probably it occurs in southern El Petén, for it is known in northern and central El Petén and in Alta Verapaz. =_Dendrophidion vinitor_= Smith.--This snake is known from Piedras Negras, El Petén and from various localities in Alta Verapaz; it is an inhabitant of humid forest and should occur in southern El Petén. =_Elaphe triaspis mutabilis_= (Cope).--The subspecies _E. triaspis mutabilis_ is known from Alta Verapaz and _E. triaspis triaspis_ from the Yucatán Peninsula, British Honduras, and Uaxactún in northern El Petén. Because of the much higher degree of resemblance between the faunas of southern El Petén and Alta Verapaz as compared with southern El Petén and Yucatán, _E. triaspis mutabilis_ would be expected to occur in southern El Petén. =_Ninia diademata nietoi_= Burger and Werler.--This snake is known from Tikal and from Alta Verapaz; it is a small cryptophile that probably occurs in southern El Petén. =_Oxyrhophus petola aequifasciatus_= Werner.--This snake, which probably is conspecific with _Oxyrhophus baileyi_ in southern Veracruz, México, is known from Tikal, British Honduras, and Alta Verapaz; it is expected in southern El Petén. =_Pliocercus elapoides salvini_= Müller.--This species is widespread in the Atlantic lowlands of southern México and northern Central America; the subspecies _P. elapoides salvini_ occurs in Alta Verapaz and probably in southern El Petén. =_Rhadinaea decorata decorata_= (Günther).--This is another small cryptophile that is widespread on the Atlantic lowlands from México to Panamá; it definitely is expected at places like Chinajá in southern El Petén. =_Scaphiodontophis annulatus_= (Duméril and Bibron).--Three subspecies of _Scaphiodontophis annulatus_ are recognized in northern Central America: _S. annulatus annulatus_ from Alta Verapaz, _S. annulatus hondurensis_ from northern Honduras, and _S. annulatus carpicinctus_ from Piedras Negras and Tikal in El Petén and from British Honduras. This rare and highly variable species probably occurs in southern El Petén. =_Tantilla schistosa schistosa_= (Bocourt).--This widespread species in Central America is known from several localities in Alta Verapaz and almost certainly occurs in southern El Petén. =_Tropidodipsas sartori sartori_= Cope.--This fossorial species has been collected in northern El Petén and in Alta Verapaz. The natives at Chinajá described to me a _coral_ having orange rings on a black body that likely was this species. =_Micrurus elegans veraepacis_= Schmidt.--This species has been collected at various localities in Alta Verapaz and in Chiapas, inhabits areas like those in southern El Petén, and probably occurs there. SUMMARY A study of the amphibians and reptiles in the rainforests of southern El Petén, Guatemala, reveals the presence of 78 species; an additional 13 species probably occur there. In this tropical area having a high amount of rainfall most of the species of amphibians and reptiles have extensive ranges in the wet forests on the Atlantic lowlands of southern México and northern Central America; some species that more frequently are found in sub-humid forests also occur. Ecologically the fauna is divided into five major habitats--aquatic, aquatic margin, fossorial, terrestrial, and arboreal. Forty-two per cent of the 78 species are wholly or partly arboreal. The fauna is most closely related to that in Alta Verapaz, Guatemala, but includes many species that occur in the Tikal-Uaxactún area in northeastern Guatemala. _Eleutherodactylus rostralis_ (Werner) and _E. rhodopis_ (Cope) are redefined and their relationships are suggested. The color phases of _Dryadophis melanolomus laevis_ and _D. m. alternatus_ are discussed; _Dryadophis sanguiventris_ Taylor is synonymized with _Dryadophis melanolomus alternatus_ (Bocourt). The breeding habits, eggs, and tadpoles of the hylid frogs _Hyla ebraccata_ and _Phyllomedusa callidryas taylori_ are described, as are the eggs and juveniles of _Laemanctus deborrei_. LITERATURE CITED BAYLOR, E. R. AND STUART, L. C. 1961. A new race of _Bufo valliceps_ from Guatemala. Proc. Biol. Soc. Washington, 74:195-202, August 11. BOGERT, C. M. AND OLIVER, J. A. 1945. A preliminary analysis of the herpetofauna of Sonora. Bull. Amer. Mus. Nat. Hist., 83:297-426, March 30. BROCCHI, P. 1881-1883 Étude des batraciens de l'Amerique Centrale. Mission scientifique au Mexique. Paris, Imprimerie Nationale, 3 (2):1-122, pls. 1-21. DUELLMAN, W. E. 1958. A review of the frogs of the genus _Syrrhophus_ in western Mexico. Occas. Papers Mus. Zool. Univ. Michigan, 594:1-15, pls. 1-3, June 6. 1960. A distributional study of the amphibians of the Isthmus of Tehuantepec, México. Univ. Kansas Publ. Mus. Nat. Hist., 13:21-72, August 16. 1961. A record size for _Drymarchon corais melanurus_. Copeia, 1960 (4):367-368, January. DUNN, E. R. AND EMLEN, J. T. 1932. Reptiles and amphibians from Honduras. Proc. Acad. Nat. Sci. Philadelphia, 84:21-32, March 22. FIRSCHEIN, I. L. AND SMITH, H. M. 1957. A high-crested race of toad (_Bufo valliceps_) and other noteworthy reptiles and amphibians from southern Mexico. Herpetologica, 13:219-222, October 31. LUNDELL, C. L. 1937. The vegetation of Petén. Carnegie Institute Washington Publ. 178:1-244, pls. 1-39. June 16. NEILL, W. T. AND ALLEN, R. 1959. Studies on the amphibians and reptiles of British Honduras. Publ. Ross Allen's Reptile Inst., 2:1-76, November 10. SAPPER, K. 1932. Klimakunde von Mittelamerika. _In_ Handbuch Klimakunde, 2:1-74, Taf. 1-13. SCHMIDT, K. P. 1936. Guatemalan salamanders of the genus _Oedipus_. Zool. Ser. Field Mus. Nat. Hist., 20:135-166, October 31. 1941. The amphibians and reptiles of British Honduras. Zool. Ser. Field Mus. Nat. Hist, 22:475-510, December 30. 1946. Turtles collected by the Smithsonian Biological Survey of the Panamá Canal Zone. Smithsonian Misc. Coll., 106 (8):1-9, pl. 1, August 1. SIMPSON, G. G. 1960. Notes on the measurement of faunal resemblance. Amer. Jour. Sci., 258-A:300-311. SMITH, H. M. AND TAYLOR, E. H. 1945. An annotated checklist and key to the snakes of Mexico. Bull. U. S. Natl. Mus., 187: iv + 239 pp., October 5. 1948. An annotated checklist and key to the amphibia of Mexico. Bull. U. S. Natl. Mus., 194: iv + 118 pp., June 17. 1950. An annotated checklist and key to the reptiles of Mexico exclusive of the snakes. Bull. U. S. Natl. Mus., 199: v + 253 pp., October 26. STUART, L. C. 1934. A contribution to a knowledge of the herpetological fauna of El Peten, Guatemala. Occas. Papers Mus. Zool. Univ. Michigan, 292:1-18, June 29. 1935. A contribution to a knowledge of the herpetology of a portion of the savanna region of central Petén, Guatemala. Misc. Publ. Mus. Zool. Univ. Michigan, 29:1-56, pls. 1-4, October 1. 1937. Some further notes on the amphibians and reptiles of the Peten forest of northern Guatemala. Copeia, 1937 (1):67-70, April 10. 1941a. Studies of Neotropical Colubrinae VIII. A revision of the genus _Dryadophis_ Stuart, 1939. Misc. Publ. Mus. Zool. Univ. Michigan, 49:1-105, pls. 1-4, March 19. 1941b. Two new species of _Eleutherodactylus_ from Guatemala. Proc. Biol. Soc. Washington, 54:197-200, December 8. 1943. Taxonomic and geographic comments on Guatemalan salamanders of the genus _Oedipus_. Misc. Publ. Mus. Zool. Univ. Michigan, 56:1-33, pls. 1-2, January 30. 1948. The amphibians and reptiles of Alta Verapaz, Guatemala. Misc. Publ. Mus. Zool. Univ. Michigan, 69:1-109, June 12. 1950. A geographic study of the herpetofauna of Alta Verapaz, Guatemala. Contr. Lab. Vert. Biol. Univ. Michigan, 45:1-77, pls. 1-9, May. 1958. A study of the herpetofauna of the Uaxactun-Tikal area of northern El Peten, Guatemala. Contr. Lab. Vert. Biol. Univ. Michigan, 75:1-30, June. TAYLOR, E. H. 1936. A taxonomic study of the cosmopolitan scincoid lizards of the genus _Eumeces_. Univ. Kansas Sci. Bull., 23:1-643, August 15. 1954. Further studies on the serpents of Costa Rica. Univ. Kansas Sci. Bull., 36:673-801, July 15. TAYLOR, E. H. AND SMITH, H. M. 1945. Summary of collections of amphibians made in Mexico under the Walter Rathbone Bacon Traveling Scholarship. Proc. U. S. Natl. Mus., 95:521-613, June 30. _Transmitted November 29, 1962._ 29-5935 UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Institutional libraries interested in publications exchange may obtain this series by addressing the Exchange Librarian, University of Kansas Library, Lawrence, Kansas. Copies for individuals, persons working in a particular field of study, may be obtained by addressing instead the Museum of Natural History, University of Kansas, Lawrence, Kansas. There is no provision for sale of this series by the University Library, which meets institutional requests, or by the Museum of Natural History, which meets the requests of individuals. However, when individuals request copies from the Museum, 25 cents should be included, for each separate number that is 100 pages or more in length, for the purpose of defraying the costs of wrapping and mailing. * An asterisk designates those numbers of which the Museum's supply (not the Library's supply) is exhausted. Numbers published to date, in this series, are as follows: Vol. 1. Nos. 1-26 and index. Pp. 1-638, 1946-1950. *Vol. 2. (Complete) Mammals of Washington. By Walter W. Dalquest. Pp. 1-444, 140 figures in text. April 9, 1948. Vol. 3. *1. The avifauna of Micronesia, its origin, evolution, and distribution. By Rollin H. Baker. Pp. 1-359, 16 figures in text. June 19, 1951. *2. A quantitative study of the nocturnal migration Of birds. By George H. Lowery, Jr. Pp. 361-472, 47 figures in text. June 29, 1951. 3. Phylogeny of the waxwings and allied birds. By M. Dale Arvey. Pp. 473-530, 49 figures in text, 13 tables. October 10, 1951. *4. Birds from the state of Veracruz, Mexico. By George H. Lowery, Jr., and Walter W. Dalquest. Pp. 531-649, 7 figures in text, 2 tables. October 10, 1951. Index. Pp. 651-681. *Vol. 4. (Complete) American weasels. By E. Raymond Hall. Pp. 1-466, 41 plates, 31 figures in text. December 27, 1951. Vol. 5. Nos. 1-37 and index. Pp. 1-676, 1951-1953. *Vol. 6. (Complete) Mammals of Utah, _taxonomy and distribution_. By Stephen D. Durrant. Pp. 1-549, 91 figures in text, 30 tables. August 10, 1952. Vol. 7. Nos. 1-15 and index. Pp. 1-651, 1952-1955. Vol. 8. Nos. 1-10 and index. Pp. 1-675. 1954-1956. Vol. 9. *1. Speciation of the wandering shrew. By James S. Findley. Pp. 1-68, 18 figures in text. December 10, 1955. 2. Additional records and extension of ranges of mammals from Utah. By Stephen D. Durrant, M. Raymond Lee, and Richard M. Hansen. Pp. 69-80. December 10, 1955. 3. A new long-eared myotis (Myotis evotis) from northeastern Mexico. By Rollin H. Baker and Howard J. Stains. Pp. 81-84. December 10, 1955. 4. Subspeciation in the meadow mouse, Microtus pennsylvanicus, in Wyoming. By Sydney Anderson. Pp. 85-104, 2 figures in text. May 10, 1956. 5. The condylarth genus Ellipsodon. By Robert W. Wilson. Pp. 105-116, 6 figures in text. May 19, 1956. 6. Additional remains of the multituberculate genus Eucosmodon. By Robert W. Wilson. Pp. 117-123, 10 figures in text. May 19, 1956. 7. Mammals of Coahuila, Mexico. By Rollin H. Baker. Pp. 125-335, 75 figures in text. June 15, 1956. 8. Comments on the taxonomic status of Apodemus peninsulae, with description of a new subspecies from North China. By J. Knox Jones, Jr. Pp. 337-346, 1 figure in text, 1 table. August 15, 1956. 9. Extensions of known ranges of Mexican bats. By Sydney Anderson. Pp. 347-351. August 15, 1956. 10. A new bat (Genus Leptonycteris) from Coahuila. By Howard J. Stains. Pp. 353-356. January 21, 1957. 11. A new species of pocket gopher (Genus Pappogeomys) from Jalisco, Mexico. By Robert J. Russell. Pp. 357-361. January 21, 1957. 12. Geographic variation in the pocket gopher, Thomomys bottae, in Colorado. By Phillip M. Youngman. Pp. 363-387, 7 figures in text. February 21, 1958. 13. New bog lemming (genus Synaptomys) from Nebraska. By J. Knox Jones, Jr. Pp. 385-388. May 12, 1958. 14. Pleistocene bats from San Josecito Cave, Nuevo León, México. By J. Knox Jones, Jr. Pp. 389-396. December 19, 1958. 15. New subspecies of the rodent Baiomys from Central America. By Robert L. Packard. Pp. 397-404. December 19, 1958. 16. Mammals of the Grand Mesa, Colorado. By Sydney Anderson. Pp. 405-414, 1 figure in text. May 20, 1959. 17. Distribution, variation, and relationships of the montane vole, Microtus montanus. By Sydney Anderson. Pp. 415-511, 12 figures in text, 2 tables. August 1, 1959. 18. Conspecificity of two pocket mice, Perognathus goldmani and P. artus. By E. Raymond Hall and Marilyn Bailey Ogilvie. Pp. 513-518, 1 map. January 14, 1960. 19. Records of harvest mice, Reithrodontomys, from Central America, with description of a new subspecies from Nicaragua. By Sydney Anderson and J. Knox Jones, Jr. Pp. 519-529. January 14, 1960. 20. Small carnivores from San Josecito Cave (Pleistocene), Nuevo León, México. By E. Raymond Hall. Pp. 531-538, 1 figure in text. January 14, 1960. 21. Pleistocene pocket gophers from San Josecito Cave, Nuevo León, México. By Robert J. Russell. Pp. 539-548, 1 figure in text. January 14, 1960. 22. Review of the insectivores of Korea. By J. Knox Jones, Jr., and David H. Johnson. Pp. 549-578. February 23, 1960. 23. Speciation and evolution of the pygmy mice, genus Baiomys. By Robert L. Packard. Pp. 579-670, 4 plates, 12 figures in text. June 16, 1960. Index. Pp. 671-690 Vol. 10. 1. Studies of birds killed in nocturnal migration. By Harrison B. Tordoff and Robert M. Mengel. Pp. 1-44, 6 figures in text, 2 tables. September 12, 1956. 2. Comparative breeding behavior of Ammospiza caudacuta and A. maritima. By Glen E. Woolfenden. Pp. 45-75, 6 plates, 1 figure. December 20, 1956. 3. The forest habitat of the University of Kansas Natural History Reservation. By Henry S. Fitch and Ronald R. McGregor. Pp. 77-127, 2 plates, 7 figures in text, 4 tables. December 31, 1956. 4. Aspects of reproduction and development in the prairie vole (Microtus ochrogaster). By Henry S. Fitch. Pp. 129-161, 8 figures in text, 4 tables. December 19, 1957. 5. Birds found on the Arctic slope of northern Alaska. By James W. Bee. Pp. 163-211, plates 9-10, 1 figure in text. March 12, 1958. *6. The wood rats of Colorado: distribution and ecology. By Robert B. Finley, Jr. Pp. 213-552, 34 plates, 8 figures in text, 35 tables. November 7, 1958. 7. Home ranges and movements of the eastern cottontail in Kansas. By Donald W. Janes. Pp. 553-572, 4 plates, 3 figures in text. May 4, 1959. 8. Natural history of the salamander, Aneides hardyi. By Richard F. Johnston and Gerhard A. Schad. Pp. 573-585. October 8, 1959. 9. A new subspecies of lizard, Cnemidophorus sacki, from Michoacán, México. By William E. Duellman. Pp. 587-598, 2 figures in text. May 2, 1960. 10. A taxonomic study of the middle-American snake, Pituophis deppei. By William E. Duellman. Pp. 599-610, 1 plate, 1 figure in text. May 2, 1960. Index. Pp. 611-626. Vol. 11. Nos. 1-10 and index. Pp. 1-703, 1958-1960. Vol. 12. 1. Functional morphology of three bats: Sumops, Myotis, Macrotus. By Terry A. Vaughan. Pp. 1-153, 4 plates, 24 figures in text. July 8, 1959. *2. The ancestry of modern Amphibia: a review of the evidence. By Theodore H. Eaton, Jr. Pp. 155-180, 10 figures in text. July 10, 1959. 3. The baculum in microtine rodents. By Sydney Anderson. Pp. 181-216, 49 figures in text. February 19, 1960. *4. A new order of fishlike Amphibia from the Pennsylvanian of Kansas. By Theodore H. Eaton, Jr., and Peggy Lou Stewart. Pp. 217-240, 12 figures in text. May 2, 1960. 5. Natural history of the bell vireo. By Jon C. Barlow. Pp. 241-296, 6 figures in text. March 7, 1962. 6. Two new pelycosaurs from the lower Permian of Oklahoma. By Richard C. Fox. Pp. 297-307, 6 figures in text. May 21, 1962. 7. Vertebrates from the barrier island of Tamaulipas, México. By Robert K. Selander, Richard F. Johnston, B. J. Wilks, and Gerald G. Raun. Pp. 309-345, pls. 5-8. June 18, 1962. 8. Teeth of Edestid sharks. By Theodore H. Eaton, Jr. Pp. 347-362, 10 figures in text. October 1, 1962. More numbers will appear in volume 12. Vol. 13. 1. Five natural hybrid combinations in minnows (Cyprinidae). By Frank B. Cross and W. L. Minckley. Pp. 1-18. June 1, 1960. 2. A distributional study of the amphibians of the Isthmus of Tehuantepec, México. By William E. Duellman. Pp. 19-72, pls. 1-8, 3 figures in text. August 16, 1960. 3. A new subspecies of the slider turtle (Pseudemys scripta) from Coahuila, México. By John M. Legler. Pp. 73-84, pls. 9-12, 3 figures in text. August 16, 1960. 4. Autecology of the copperhead. By Henry S. Fitch. Pp. 85-288, pls. 13-20, 26 figures in text. November 30, 1960. 5. Occurrence of the garter snake, Thamnophis sirtalis, in the Great Plains and Rocky Mountains. By Henry S. Fitch and T. Paul Maslin. Pp. 289-308, 4 figures in text. February 10, 1961. 6. Fishes of the Wakarusa river in Kansas. By James E. Deacon and Artie L. Metcalf. Pp. 309-322, 1 figure in text. February 10, 1961. 7. Geographic variation in the North American cyprinid fish, Hybopsis gracilis. By Leonard J. Olund and Frank B. Cross. Pp. 323-348, pls. 21-24, 2 figures in text. February 10, 1961. 8. Descriptions of two species of frogs, genus Ptychohyla; studies of American hylid frogs, V. By William E. Duellman. Pp. 349-357, pl. 25, 2 figures in text. April 27, 1961. 9. Fish populations, following a drought, in the Neosho and Marais des Cygnes rivers of Kansas. By James Everett Deacon. Pp. 359-427, pls. 26-30, 3 figs. August 11, 1961. 10. Recent soft-shelled turtles of North America (family Trionychidae). By Robert G. Webb. Pp. 429-611, pls. 31-54, 24 figures in text. February 16, 1962. Index. Pp. 613-624. Vol. 14. 1. Neotropical bats from western México. By Sydney Anderson. Pp. 1-8. October 24, 1960. 2. Geographic variation in the harvest mouse. Reithrodontomys megalotis, on the central Great Plains and in adjacent regions. By J. Knox Jones, Jr., and B. Mursaloglu. Pp. 9-27, 1 figure in text. July 24, 1961. 3. Mammals of Mesa Verde National Park, Colorado. By Sydney Anderson. Pp. 29-67, pls. 1 and 2, 3 figures in text. July 24, 1961. 4. A new subspecies of the black myotis (bat) from eastern Mexico. By E. Raymond Hall and Ticul Alvarez. Pp. 69-72, 1 figure in text. December 29, 1961. 5. North American yellow bats, "Dasypterus," and a list of the named kinds of the genus Lasiurus Gray. By E. Raymond Hall and J. Knox Jones, Jr. Pp. 73-98, 4 figures in text. December 29, 1961. 6. Natural history of the brush mouse (Peromyscus boylii) in Kansas with description of a new subspecies. By Charles A. Long. Pp. 99-111, 1 figure in text. December 29, 1961. 7. Taxonomic status of some mice of the Peromyscus boylii group in eastern Mexico, with description of a new subspecies. By Ticul Alvarez. Pp. 113-120, 1 figure in text. December 29, 1961. 8. A new subspecies of ground squirrel (Spermophilus spilosoma) from Tamaulipas, Mexico. By Ticul Alvarez. Pp. 121-124. March 7, 1962. 9. Taxonomic status of the free-tailed bat, Tadarida yucatanica Miller. By J. Knox Jones, Jr., and Ticul Alvarez. Pp. 125-133, 1 figure in text. March 7, 1962. 10. A new doglike carnivore, genus Cynaretus, from the Clarendonian Pliocene, of Texas. By E. Raymond Hall and Walter W. Dalquest. Pp. 135-138, 2 figures in text. April 30, 1962. 11. A new subspecies of wood rat (Neotoma) from northeastern Mexico. By Ticul Alvarez. Pp. 139-143. April 30, 1962. 12. Noteworthy mammals from Sinaloa, Mexico. By J. Knox Jones, Jr., Ticul Alvarez, and M. Raymond Lee. Pp. 145-159, 1 figure in text. May 18, 1962. 13. A new bat (Myotis) from Mexico. By E. Raymond Hall. Pp. 161-164, 1 figure in text. May 21, 1962. 14. The mammals of Veracruz. By E. Raymond Hall and Walter W. Dalquest. Pp. 165-362, 2 figures. May 20, 1963. 15. The recent mammals of Tamaulipas, México. By Ticul Alvarez. Pp. 363-473, 5 figures in text. May 20, 1963. More numbers will appear in volume 14. Vol. 15. 1. The amphibians and reptiles of Michoacán, México. By William E. Duellman. Pp. 1-148, pls. 1-6, 11 figures in text. December 20, 1961. 2. Some reptiles and amphibians from Korea. By Robert G. Webb, J. Knox Jones, Jr., and George W. Byers. Pp. 149-173. January 31, 1962. 3. A new species of frog (Genus Tomodactylus) from western México. By Robert G. Webb, Pp. 175-181, 1 figure in text. March 7, 1962. 4. Type specimens of amphibians and reptiles in the Museum of Natural History, the University of Kansas. By William E. Duellman and Barbara Berg. Pp. 183-204. October 26, 1962. 5. Amphibians and Reptiles of the Rainforests of Southern El Petén, Guatemala. By William E. Duellman. Pp. 205-249, pls. 7-10, 6 figures in text. October 4, 1963. More numbers will appear in volume 15. 
38440	----	UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 13, No. 2, pp. 19-72, pls. 1-8, 3 figs. August 16, 1960 A Distributional Study of the Amphibians of the Isthmus of Tehuantepec, México BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1960 UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 13, No. 2, pp. 19-72, pls. 1-8, 3 figs. August 16, 1960 A Distributional Study of the Amphibians of the Isthmus of Tehuantepec, México BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1960 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Robert W. Wilson Volume 13, No. 2, pp. 19-72, pls. 1-8, 3 figs. Published August 16, 1960 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED IN THE STATE PRINTING PLANT TOPEKA, KANSAS 1960 28-3859 A Distributional Study of the Amphibians of the Isthmus of Tehuantepec, México BY WILLIAM E. DUELLMAN CONTENTS PAGE INTRODUCTION 21 Acknowledgments 23 Field Studies in the Isthmus of Tehuantepec 23 Sources of Material 24 DESCRIPTION OF THE ISTHMUS OF TEHUANTEPEC 25 Physiography 25 Climate 28 Vegetation 29 The Sierra de los Tuxtlas 32 GAZETTEER 33 THE AMPHIBIAN FAUNA OF THE LOWLANDS 37 Composition of the Fauna 37 Ecology of the Fauna 38 Distribution of the Fauna 42 THE AMPHIBIAN FAUNA OF THE FOOTHILLS AND ADJACENT HIGHLANDS 44 ESTABLISHMENT OF PRESENT PATTERNS OF DISTRIBUTION 45 ACCOUNTS OF SPECIES 49 SUMMARY 68 LITERATURE CITED 69 INTRODUCTION Few regions in Middle America are so important zoogeographically as is the Isthmus of Tehuantepec, that neck of land connecting North America with Central America, separating the Pacific Ocean from the Gulf of Mexico by a distance of only about 220 kilometers (airline), and forming a low break between the highlands of México and those of Central America. Before World War II the isthmus could be reached readily only by railroad or by ocean vessel to Salina Cruz or Coatzacoalcos. With the advent of roads, principally the Trans-isthmian Highway, vast areas of the interior of the isthmus became accessible to biologists. Nevertheless, long before roads were built in the isthmian region collectors and biologists visited it, especially the town of Tehuantepec, from which collections date back to the 1870's. Therefore, it is rather surprising that no attempt has been made to present a faunal list of the amphibians or reptiles of the isthmus. Ruthven (1912) summarized his collections from the vicinity of Cuatotolapam, Veracruz, and Hartweg and Oliver (1940) presented an annotated list of the species collected by them in the vicinity of Tehuantepec. In recent years there have been only a few papers reporting species from the isthmus (Fugler and Webb, 1957; Langebartel and Smith, 1959). The zoogeographic significance of the Isthmus of Tehuantepec is exemplified by the works of Burt (1931), Duellman (1958), Gloyd (1940), Oliver (1948), and Stuart (1941), who in their discussions of evolution and dispersal of various genera of reptiles, pointed out that the Isthmus of Tehuantepec was a region of zoogeographic importance. Originally I intended to study the entire herpetofauna of the isthmus. But I have not had opportunity to study all of the reptiles, and I have not had the inclination to solve certain taxonomic problems concerning them. The amphibians that I collected, together with all other known specimens in museums, have been studied. Therefore, the present report is concerned only with the amphibians. Only the amphibians of the lowlands of the isthmus have been sampled adequately. Although I have commented on the highland species in the discussion of distribution, they are not included in the systematic section, which deals solely with the 36 species definitely known to occur in the lowlands of the isthmus. Among the species of amphibians that I would expect to occur in the isthmus, the only one not yet found there is _Hyla phaeota_. Sufficient specimens of most of the species are available to show their variation in the isthmus. Consequently, the systematics of these amphibians is on a fairly substantial basis. Probably certain species in the isthmian region will be found to be conspecific with others to the south, for example _Hyla ebraccata_ with _Hyla leucophyllata_ and _Hyla robertmertensi_ with _Hyla underwoodi_. Nevertheless, such taxonomic changes will not affect the distributional picture presented here. Our greatest lack of knowledge concerning the amphibians is about their life histories, as may be illustrated by the following questions, all of which now are without definite answers. Where do many of the small frogs conceal themselves during the dry season? What amount of, if any, interspecific competition exists among several species of tree frogs, all of which breed in the same ponds? What factors in the environment permit certain amphibians, but not others, to live in the humid rainforests, as well as in the arid tropical scrub forest? The answers to these questions and many others must await additional field studies. The purpose of this paper is to make known the species of amphibians living in the Isthmus of Tehuantepec, to describe the environments in which they live, and to discuss their distribution in the isthmus. With respect to the distribution of animals in the Isthmus of Tehuantepec I will attempt to explain the present patterns of distribution with special reference to climatic fluctuation in the Pleistocene. _Acknowledgments_ My extensive field work in the Isthmus of Tehuantepec was made possible by grants from the Penrose Fund of the American Philosophical Society (1956) and the Bache Fund of the National Academy of Sciences (1958). Furthermore, my field work received the hearty support of the Museum of Zoology at the University of Michigan; for their cooperation I am indebted to Norman Hartweg, T. H. Hubbell, and Henry van der Schalie. In the course of my studies I received helpful suggestions from Norman Hartweg, L. C. Stuart, and Charles F. Walker, to whom I am grateful. For permission to examine specimens in their care I thank Doris M. Cochran, Hobart M. Smith, and Richard G. Zweifel. I am deeply indebted to Thomas MacDougall for many suggestions and for aid in preparing the gazetteer. I am most grateful for the efforts of my field companions, Richard E. Etheridge, Jerome B. Tulecke, John Wellman, and especially my wife, Ann S. Duellman, who spent many long days and nights gathering much of the data on which this report is based. Our work in the isthmus was furthered by the generous help and hospitality of many residents, especially the late Wilbur Barker of Tehuantepec, Fortunado Delgado of Rancho Las Hojitas near Acayucan, César Fárjas of Donají, and Juan Mayol of San Andrés Tuxtla. Profesor Jordi Juliá Z. of the Laboratorio de Entomología, Comisión del Papaloapan, Ciudad Alemán, Veracruz, helped make possible my field work in 1959; for this he has my sincere thanks. In conclusion I express my gratitude to Ing. Juan Lozano Franco, Secretaria de Agricultura y Ganadería, for providing me with the necessary permits. _Field Studies in the Isthmus of Tehuantepec_ I first visited the Isthmus of Tehuantepec and collected on the Pacific lowlands of the isthmus in July, 1955. At that time heavy rains and impassable roads restricted travelling. In February and March of 1956 my wife and I concentrated our efforts in the central region between the Río Jaltepec and Matías Romero, but also made several trips across the isthmus to gather ecological data in the dry season. In July of the same year, accompanied by Richard E. Etheridge, we again crossed the isthmus several times in order to gather ecological data in the wet season, and studied especially hylid frogs, most of which had not been seen in the dry season. Accompanied by Jerome B. Tulecke and John Wellman, I collected again in the isthmus in July, 1958, between Salina Cruz and Tehuantepec, and between Coatzacoalcos and Cosoleacaque. In March and April, 1959, I collected at Ciudad Alemán. Nearly 1200 specimens of 30 species of amphibians were thus collected in the Isthmus of Tehuantepec; all specimens are now in the Museum of Zoology at the University of Michigan. Of other species known from the isthmus, I have had field experience with all but one (_Bolitoglossa veracrucis_) in other parts of México. _Sources of Material_ There are in museum collections nearly 3000 specimens of amphibians with reliable data from the Isthmus of Tehuantepec. Among the first herpetological specimens collected in the isthmian region are those assembled by Francis Sumichrast in the 1870's from the vicinity of Santa Efigenia and Tapanatepec, Oaxaca. These specimens were sent to the United States National Museum and the Museum National d'Histoire Naturelle in Paris; many served as the types of new species: _Bufo canaliferus_ Cope, _Eleutherodactylus rugulosus_ Cope, _Syrrhophus leprus_ Cope, and _Hylella sumichrasti_ Brocchi. In 1911 Alexander G. Ruthven collected in the savanna country near Cuatotolapam, Veracruz; the report on his collections (1912) is the first dealing with the herpetofauna of a part of the isthmus. His specimens are in the collection of the University of Michigan Museum of Zoology. Norman Hartweg and James A. Oliver collected for the University of Michigan Museum of Zoology in the vicinity of Tehuantepec, Oaxaca, during the summer of 1936. The results of their work were published as an annotated list of species occurring on the Pacific slopes of the isthmus (1940). Hobart M. Smith collected in the vicinity of Tehuantepec in January, 1940; his specimens are in the United States National Museum. Specimens collected by Smith served as the types of _Eleutherodactylus avocalis_ Taylor and Smith and _Diaglena reticulata_ Taylor. Walter W. Dalquest collected vertebrates for the University of Kansas in southern Veracruz in the winters of 1947 and 1948; he spent about six months on the Gulf lowlands of the isthmus, principally in the vicinity of Jesús Carranza. For the past two decades Thomas MacDougall, a resident of New York City, has spent his winters collecting biological specimens in southern México. He makes his headquarters at Tehuantepec, but his compulsion to see the "back country" has taken him to many remote parts of southern Oaxaca. His earlier collections are in the American Museum of Natural History; the later ones are in the University of Illinois Museum of Natural History. Minor collections include those made by Matthew W. Stirling at San Lorenzo, Veracruz, February-April, 1946 (United States National Museum), by Fred G. Thompson on a trip across the isthmus in December, 1955 (University of Michigan Museum of Zoology), by the University of Kansas Museum of Natural History field party under the direction of Rollin H. Baker at Tolosita, Oaxaca, and by David A. Langebartel and associates from southern Oaxaca in June, 1958 (University of Illinois Museum of Natural History). In the collections of the United States National Museum are several species of amphibians sent to the museum from Tehuantepec by Francis Sumichrast. These include _Bolitoglossa platydactyla_ (USNM 30305, 30344-6, 30528), _Bolitoglossa rufescens_ (10042), _Chiropterotriton chiropterus_ (30347), _Lineatriton lineola_ (30353), _Parvimolge townsendi_ (30352), _Pseudoeurycea cephalica_ (30350), _Thorius pennatulus_ (30348-9), _Hyla miotympanum_ (30302-3), and _Hyla picta_ (30304). Because of the poor condition of the specimens, determinations of those listed as _Bolitoglossa rufescens_ and _Pseudoeurycea cephalica_ are uncertain. With the exception of the _Bolitoglossa rufescens_, which is stated to have come from Santa Efigenia, all of these specimens are catalogued as having come from Tehuantepec. None of these species has since been recorded from the Pacific slopes of the isthmus; however, they all occur in the vicinity of Orizaba, Veracruz. Probably Sumichrast carried the specimens with him from Orizaba, his home before moving to Santa Efigenia, and shipped them from Tehuantepec to the United States National Museum. These species definitely should not be considered as inhabitants of the Pacific slopes of the Isthmus of Tehuantepec. DESCRIPTION OF THE ISTHMUS OF TEHUANTEPEC The Isthmus of Tehuantepec is a strip of land forming a low pass, which separates the mountain masses of México proper from those of Central America, and at the same time provides a continuum of lowlands from the Gulf of Mexico to the Pacific Ocean. This topography combines with the climatic conditions to create extremely diverse environments, the distribution of which can be adequately understood only after an acquaintance with the topography and climate of the region. _Physiography_ In east-central Oaxaca the mountain masses comprising the Sierra Madre Oriental and the Sierra del Sur terminate in a series of ranges--Sierra de Juárez, Sierra de los Míjes, and Sierra de Choapam. From lofty peaks, such as Cerro de Zempoaltepetl (3400 meters), the highlands diminish eastward to succeedingly lower ridges, until in the middle of the Isthmus of Tehuantepec the continental divide is about 250 meters above sea level. Eastward from this low divide the land rises to form the Sierra Madre de Chiapas, which is continuous with the highland masses of Guatemala. For the purposes of this description, the lowlands of the isthmus may be divided into three parts--the Gulf Coastal Plain, the central ridges, and the Pacific Coastal Plain, which in the isthmus is called the Plains of Tehuantepec (Figs. 1 and 2). The Gulf Coastal Plain is broad and fairly level near the coast, but rolling in the interior. The plain, throughout most of its length in the isthmus, is at least 75 kilometers wide. The majority of the region in the isthmus is drained by the Río Coatzacoalcos, which flows in a northerly course to the Gulf of Mexico. The western part is drained by the Río San Juan, the principal tributary of the Río Papaloapan. Behind the coastal dunes are frequent, and sometimes large, lagoons. Immediately inland from Coatzacoalcos and along the lower stretches of the Río Papaloapan are extensive marshes. Essentially the entire coastal plain, with the exception of the coastal dunes, consists of rich alluvial deposits. [Illustration: FIG. 1. Map of the Isthmus of Tehuantepec based on the American Geographical Society's "Map of Hispanic America on the Scale of 1:1,000,000." The localities shown are numbered in the gazetteer; the numerical sequence of localities is an arrangement whereby north takes precedence over south and west over east. 1. Alvarado. 2. Lerdo de Tejada. 3. Tlacotalpan. 4. Tula. 5. Tecolapan. 6. Amatitlán. 7. Cosamaloapan. 8. Chacaltianguis. 9. Novillero. 10. Ciudad Alemán. 11. Papaloapan. 12. Tuxtepec. 13. Cuatotolapam. 14. Hueyapan. 15. Berta. 16. Coatzacoalcos. 17. Ayentes. 18. Río de las Playas. 19. Cosoleacaque. 20. Minatitlán. 21. Acayucan. 22. Aquilera. 23. San Lorenzo. 24. Naranja. 25. Suchil. 26. Jesús Carranza. 27. La Oaxaqueña. 28. Ubero. 29. Donají. 30. Tolosita. 31. El Modelo. 32. Sarabia, 33. Guichicovi. 34. La Princesa. 35. Santa María Chimalapa. 36. Matías Romero. 37. Santo Domingo Petapa. 38. El Barrio. 39. Palmar. 40. Chivela. 41. Santiago Chivela. 42. Nizanda. 43. Agua Caliente. 44. Portillo Los Nanches. 45. Ixtepec. 46. La Ventosa. 47. Zanatepec. 48. Unión Hidalgo. 49. Tres Cruces. 50. Juchitán. 51. Escurano. 52. Salazar. 53. Santa Efigenia. 54. Tequisistlán. 55. Cerro de Quiengola. 56. San Pablo. 57. Mixtequilla. 58. Tapanatepec. 59. Zarzamora. 60. Limón. 61. Tehuantepec. 62. Bisilana. 63. Santa Lucía. 64. Cerro de Arenal. 65. Cerro de San Pedro. 66. La Concepción. 67. Tenango. 68. San Antonio. 69. Huilotepec. 70. Salina Cruz.] [Illustration: FIG. 2. Topographic profile of the Isthmus of Tehuantepec showing major localities along the Trans-isthmian Highway and major types of vegetation. Vertical exaggeration approximately 165 times.] The central ridges extend from the Río Jaltepec southward to within 40 kilometers of the Pacific coast. It is in this area that the continuity of the high ridges and volcanic peaks, which extend nearly the entire length of the Americas, is interrupted at a point almost directly in line with the shortest distance between the two oceans. The northern part of this central region consists of hills dissected by tributaries of the Río Coatzacoalcos; the principal ones from north to south are--Río Jaltepec, Río Tortuguero, Río Sarabia, and Río Malatengo. The plains of Chivela are south of these rivers and lie at an elevation of about 200 meters; at the southern edge of these plains a range of hills rises to 250 to 400 meters above sea level. These hills drop abruptly to the Plains of Tehuantepec. In the northern and central parts of this central region the rocks are granitic; the hills to the south of the Plains of Chivela are limestone. The Pacific Coastal Plain or Plains of Tehuantepec have a maximum width of about 30 kilometers. From the base of the hills at an elevation of about 75 meters the plains slope gradually to the sea. To the west of the Río Tehuantepec and to the east of the Plains of Tehuantepec at the base of the Sierra Madre de Chiapas, the coastal plain becomes much narrower; in these places the continuity of the plain is frequently interrupted by low north-south ridges extending outward from the mountains or by isolated hills. The soil is poor, varying from volcanic rock to gravel and sand. _Climate_ The prevailing winds are from the north across the Gulf of Mexico. These moisture-laden winds precipitate most of their moisture north of the central ridges. This results in high rainfall on the northern slopes and Gulf Coastal Plain and relatively little rainfall on the southern slopes and the Pacific Coastal Plain. Precipitation is cyclic; there is a marked wet and a dry season throughout the region, but this is most noticeable on the Pacific lowlands (Fig. 3). At Salina Cruz on the Pacific Ocean the average annual rainfall is 1040 mm. (Contreras, 1942); of this amount, only 15 mm. falls from November through April. On the Gulf Coastal Plain (Minatitlán station) the average annual rainfall is 3085 mm. In this region the driest months are February through May, during which time 236 mm. of rain falls. At Salina Cruz the wettest month is June; at Minatitlán it is September. There is little variation in temperature throughout the isthmus; the average annual temperature at Salina Cruz is 26.6° C.; that at Minatitlán is 26.2° C. During the winter when masses of air from the arctic move southward into the Great Plains of the United States, cool winds blow across the isthmus. These are usually accompanied by overcast sky and sometimes a slight amount of precipitation. These "nortes" may cause a drop in temperature of about six to eight degrees in a few hours. [Illustration: FIG. 3. Climatographs for Minatitlán, Veracruz, and Salina Cruz, Oaxaca, based on data given by Contreras (1942). Plotted points are for mean monthly temperatures and rainfall; months are indicated by numbers.] _Vegetation_ The topography and climate combine to produce drastically different types of climax vegetation on the northern and southern lowlands of the isthmus. The picture is somewhat complicated by the savannas on the Gulf Coastal Plain, which, as will be shown later, are dependent upon edaphic features more than climatic conditions. The following brief account of the vegetation in the Isthmus of Tehuantepec is based on data provided by Williams (1939) and Goldman (1951), supplemented by personal observations. The purpose of this description is not to analyze the flora of the isthmus, but to give the reader a picture of this aspect of the biota of the major environments with which I shall be concerned in the ensuing discourse on the amphibians of the region. The three divisions of the isthmus recognized in the account of the physiography serve equally well in describing the vegetation. Those divisions are as follows: Gulf Lowlands On the lowlands north of the continental divide and extending to the Gulf of Mexico are three major types of vegetation--tropical rainforest, arid tropical scrub forest, and savanna. Aside from these, there are marshes and lagoons near the coast. On the coastal dunes there are thickets of sea grape, patches of _Cenchrus_, and clumps or scattered _Opuntia_. The lagoons are bordered by mangrove thickets made up primarily of _Lonchocarpus hondurensis_. In the marshes along the lower Río Coatzacoalcos and Río Papaloapan the tall tough grass, _Gynerium sagittatum_, is common. According to Beard (1953: 291) the development of savanna vegetation is dependent upon soil, topography, and drainage. Level regions having permeable soil horizons lying on top of an impermeable horizon provide poor drainage. In most savanna regions in the Americas the grasslands become waterlogged or even partly flooded during the rainy season and desiccated in the dry season. Many ecologists and phytogeographers have postulated that savannas are either man made or are examples of a fire climax. Beard (_op. cit._: 203) provided multitudinous evidence that the association of savanna vegetation and certain types of edaphic and topographic conditions was so strongly marked that grassland is the natural vegetation in these areas. Savannas are scattered through southern Veracruz eastward to British Honduras. These usually are grasslands having scattered trees or clumps of trees around depressions, which may contain water throughout the year (Pl. 1, fig. 1). According to Williams (_op. cit._), the most common trees in the savannas in southern Veracruz are _Ceiba pentandra_, _Chlorophora tinctoria_, and _Byrsonima crassifolia_. Lying in a rain shadow cast by the Tuxtlas and on sandy and well-drained soils is a dense xerophytic forest. The crown of this deciduous forest usually is little more than ten to twelve meters above the ground (Pl. 1, fig. 2). Conspicuous trees in this scrub forest are _Acacia cornigera_, _Bauhinia latifolia_, _Calliandra bijuga_, _Cassia laevigata_, _Guazuma ulmifolia_, and various species of _Bursera_. The most extensive type of vegetation on the Gulf Coastal Plain is a tall evergreen forest resembling tropical rainforest. Although this forest is made up of many species of trees that are characteristic of true rainforest, the forest on the Gulf Coastal Plain cannot be classified as true rainforest, neither by the climatic conditions, nor the structure of the forest. The seasonal variation in rainfall probably is the chief factor in hindering the development of a rainforest climax vegetation. Usually a minimum of 65 mm. of rainfall each month is considered essential for the development of true rainforest. At Minatitlán the average rainfall for March (39 mm.) and April (36 mm.) is far below this minimum. Structurally, this forest has a crown about 30-35 meters above the ground but individual trees rising five meters or more above the crown (Pl. 2, figs. 1-2). There is no clear stratification within the forest; in many parts of it there are dense growths of bushes, small trees, and palms. The forest on the Gulf Coastal Plain, therefore, most properly might be referred to as a quasi-rainforest, a term that has been applied to other such forests in tropical America. Among the abundant and dominant trees in this forest are _Swietenia macrophylla_, _Calophyllum brasiliense_, _Achras zapota_, _Ceiba pentandra_, _Castilla elastica_, _Cedrela mexicana_, _Tabebuia Donnell-Smithi_, _Calocarpum mammosum_, _Bombax ellipticum_, and a variety of _Ficus_. Epiphytes and Ilianas are abundant. Central Ridges The vegetation of the central ridges of the isthmus is, for the most part, transitional between the tall rainforest of the Gulf Coastal Plain and the low xerophytic scrub forest of the semi-arid Pacific Coastal Plain. On the northern slopes of the ridges the rainforest is more poorly developed than on the plains to the north. Many of the same species of trees are present, including _Ceiba pentandra_, _Cedrela mexicana_, _Swietenia macrophylla_, and _Ficus_ sp.; nevertheless, these seldom are as large as members of the same species in the forest on the plains. Other species present on the forested slopes include _Tabebuia Donnell-Smithi_, _Zanthoxylum melanostictum_, _Pithecolobium arboreum_, and a species of _Pterocarpus_. The structure of this forest differs from that on the Gulf Coastal Plain in that there is no continuous upper canopy and there is a dense undergrowth (Pl. 3, fig. 1). This type of forest extends from Mogoñe southward to about Matías Romero. In the vicinity of Matías Romero open pine-oak forest (_Pinus caribaea_ and _Quercus_ sp.) is found on some ridges as low as 250 meters above sea level. On the Plains of Chivela in the southern part of the central region the vegetation takes on a semi-arid appearance, especially in a savanna on the plains. Clumps of small trees and bushes, consisting of _Croton nivea_, _Cordia cana_, _Jacquinia aurantiaca_, _Calycophyllum candidissimum_, and _Cassia emarginata_, are scattered on a grassy plain, from which rise widely-spaced palms of an unknown species (Pl. 3, fig. 2). Pacific Coastal Plain The vegetation of the Pacific lowlands definitely is semi-arid in character. Most of the trees are deciduous, thorny, and short. During the dry season the landscape presents a barren appearance, but shortly after the first summer rains dense green foliage appears (Pl. 4, figs. 1 and 2). Between Juchitán and La Ventosa few trees are more than two meters high (Pl. 5, fig. 1). In many areas the trees and bushes form an almost impenetrable tangle, whereas on especially rocky soils or on slopes those plants are more widely spaced. Abundant and widespread species of trees on the Plains of Tehuantepec include _Acacia cymbispina_, _Prosopis chilensis_, _Caesalpinia coriaria_, _Caesalpinia eriostachys_, _Celtis iguanaea_, _Cordia brevispicata_, _Jatropha aconitifolia_, and _Crescentia alata_. Montane Vegetation In order to illustrate the interruption of subtropical and temperate types of vegetation by the lowlands of the Isthmus of Tehuantepec, it is necessary to digress for a moment from the isthmus and consider the types of vegetation present on the adjacent highlands. On the higher peaks, such as Cerro de Zempoaltepetl, above about 2500 meters is fir forest (_Abies religiosa_); lower on the slopes are extensive pine forests, which on some slopes are mixed with oak or replaced entirely by oaks. Subtropical cloud forest, characterized by relatively cool temperatures and high humidity, is found at elevations usually between 1000 and 1800 meters on the windward slopes of the Sierra Madre Oriental in Veracruz and northern Oaxaca and on the northern and southern slopes of the Chiapan-Guatemalan Highlands. None of these forest types is continuous across the Isthmus of Tehuantepec. _The Sierra de los Tuxtlas_ Although actually located in the region of the Isthmus of Tehuantepec, the Sierra de los Tuxtlas, because of its isolated position, need not be considered in great detail in analyzing the distribution of animals inhabiting the lowlands of the isthmus. Nevertheless because some species living in the highlands adjacent to the isthmus also live in the Tuxtlas, this range is briefly described here. The Sierra de los Tuxtlas is a range of volcanos lying near the Gulf Coast in southern Veracruz between the mouths of the Río Papaloapan and the Río Coatzacoalcos. Volcán San Martín, the highest peak, rises above 1800 meters. This range of volcanos is surrounded by lowlands, which immediately to the south and west are covered with savanna and in places by scrub forest. The luxuriant nature of the vegetation on these volcanos indicates that this range receives much more rainfall than the surrounding lowlands. Especially on the northern slopes, tropical rainforest is well developed; this is replaced at about 1200 meters by cloud forest. The southern and western slopes are drier, for the lower slopes are covered with a scrubby, but evergreen, forest. Detailed comments on the herpetofauna of the Tuxtlas have been omitted purposefully, for the reptiles and amphibians of the region currently are being studied by Douglas Robinson. GAZETTEER The following localities are those referred to in the text. The name of the locality (listed alphabetically by states) is followed by latitude, longitude, elevation, general description (town, ranch, etc.), and general type of habitat. Unless otherwise noted, distances are straight-line (airline) distances in kilometers. The localities have been plotted from the American Geographical Society's "Map of Hispanic America on the Scale of 1:1,000,000" (Millionth Map). Numbers in brackets identify the position of a locality on the accompanying map (Fig. 1). _Oaxaca_ Agua Caliente.--Lat. 16° 38'; long. 94° 48'; elev. 140 m. A hot spring, 6.9 km. north of La Ventosa on the Trans-isthmian Highway; arid scrub forest [43]. Arenal, Cerro de.--Lat. 16° 18'; long. 95° 32'; elev. 925 m. (crest). A ridge northeast of Tenango; scrub forest on slopes and pine-oak forest on top [64]. Barrio, El.--Lat. 16° 38'; long. 95° 07'; elev. 314 m. A village about 10 kilometers southwest of Matías Romero; transition between scrub forest and broadleaf hardwood forest [38]. Bisilana.--Lat. 16° 20'; long. 95° 13'; elev. 35 m. A place name for a former ranch at the edge of Tehuantepec; open arid scrub forest [62]. Chivela.--Lat. 16° 20'; long. 95° 01'; elev. 195 m. A village on the Trans-isthmian Railroad, 26 kilometers by rail south of Matías Romero and on the western edge of the semi-arid Plains of Chivela [40]. Concepción.--Lat. 16° 17'; long. 95° 29'; elev. 1200 m. A ranch on the slopes of Cerro Arenal, east-northeast of Tenango; dry pine-oak forest [66]. Coyol.--Exact position unknown; according to Smith and Taylor (1950: 10), Coyol is "between San Antonio and Las Cruces." Donají.--Lat. 17° 13'; long. 95° 02'; elev. 90 m. A village at Km. 155 on the Trans-isthmian Highway; rainforest [29]. Escurano.--Lat. 16° 25'; long. 95° 27'; elev. 500 m. A ranch about 25 kilometers west-northwest of Tehuantepec; arid scrub forest [51]. Guichicovi, San Juan.--Lat. 16° 58'; long. 95° 06'; elev. 250 m. A village on the north slopes of the isthmus, 12 kilometers north-northwest of Matías Romero; cleared hardwood forest and coffee plantations [33]. Huilotepec.--Lat. 16° 14'; long. 95° 09'; elev. 30 m. A small village on the Río Tehuantepec, 13 kilometers south-southeast of Tehuantepec; open arid scrub forest [69]. Ixtepec.--Lat. 16° 34'; long. 95° 06'; elev. 60 m. A town and railroad junction on the northwestern edge of the Plains of Tehuantepec; arid scrub forest [45]. Juchitán.--Lat. 16° 26'; long. 95° 02'; elev. 15 m. A town on the Plains of Tehuantepec, 22 kilometers by road east-northeast of Tehuantepec; arid scrub forest [50]. Limón.--Lat. 16° 20'; long. 95° 29'; elev. 600 m. A former agrarian colony and now a small ranch about 27 kilometers west of Tehuantepec; arid scrub forest [60]. Matías Romero.--Lat. 16° 53'; long. 95° 02'; elev. 200 m. A town on the Trans-isthmian Highway and railroad in the hills near the crest of the isthmus; broadleaf hardwood forest and open pine-oak forest [36]. Mixtequilla.--Lat. 16° 24'; long. 95° 18'; elev. 40 m. A village on the Río Tehuantepec, northwest of Tehuantepec; dense scrub forest [57]. Modelo, El.--Lat. 17° 07'; long. 94° 43'; elev. 200 m. An old rubber plantation on the Río Chalchijapa, a tributary to the Río Coatzacoalcos; rainforest [31]. Nanches, Portillo Los.--Lat. 16° 35'; long. 95° 37'; elev. 500 m. A place name, about 4 kilometers southeast of Totolapilla; scrub forest [44]. Nizanda.--Lat. 16° 42'; long. 95° 02'; elev. 150 m. A village on the Trans-isthmian Railroad between Chivela and Ixtepec; dense scrub forest [42]. Nueva Raza.--Exact location unknown; according to Thomas MacDougall, this locality is in the lowlands of northern Oaxaca; rainforest. Palmar.--Lat. 16° 43'; long. 94° 40'; elev. 300 m. A small ranch on the west base of Cerro Atravesado; scrub forest [39]. Papaloapan.--Lat. 18° 11'; long. 96° 06'; elev. 25 m. A small village on the Río Papaloapan in northern Oaxaca; low evergreen forest and savanna [11]. Princesa, La.--Lat. 16° 56'; long. 95° 02'; elev. 150 m. A ranch on the northern slopes of the isthmus, 6 kilometers by road north of Matías Romero; poorly developed rainforest [34]. Quiengola, Cerro de.--Lat. 16° 24'; long. 95° 22'; elev. 900 m. (crest). A hill 15 kilometers west-northwest of Tehuantepec; dense scrub forest on slopes and scattered pines on top [55]. Salazar.--Lat. 16° 25'; long. 95° 20'; elev. 45 m. A ranch on the Río Tehuantepec, northwest of Tehuantepec; dense scrub forest [52]. Salina Cruz.--Lat. 16° 10'; long. 95° 12'; sea level. A port on the Golfo de Tehuantepec; open arid scrub forest [70]. Collections were made in the vicinity of the town and in the open scrub forest 2.4 kilometers north at an elevation of 20 meters. San Antonio.--Lat. 16° 15'; long. 95° 22'; elev. 40 m. A ranch about 25 kilometers west-southwest of Tehuantepec; arid scrub forest [68]. San Pablo.--Lat. 16° 24'; long. 95° 18'; elev. 40 m. A ranch on the Río Tehuantepec, northwest of Tehuantepec; dense scrub forest [56]. Cerro San Pablo probably is the hill north of this ranch; this is shown on some maps as Cerro de los Amates. San Pedro, Cerro de.--Lat. 16° 18'; long. 95° 28'; elev. about 1100 m. (crest). A ridge about 24 kilometers west of Tehuantepec and east of Cerro Arenal; scrub forest on slopes and pine-oak forest on top [65]. Santa Efigenia.--Lat. 16° 25'; long. 94° 13'; elev. 500 m. A ranch on the southern slopes of the Sierra Madre de Chiapas, 8 kilometers north-northwest of Tapanatepec; scrub forest. Former home of Francis Sumichrast [53]. Santa Lucía.--Lat. 16° 18'; long. 95° 28'; elev. 800 m. A place name for a former ranch on the east slopes of Cerro Arenal; scrub forest [63]. Santa María Chimalapa.--Lat. 16° 55'; long. 94° 42'; elev. 296 m. A village on the Río de los Milagros, a tributary to the Río Coatzacoalcos; rainforest [35]. Santiago Chivela.--Lat. 16° 42'; long. 94° 53'; elev. 200 m. A village on the Trans-isthmian Highway, 13.4 kilometers by road south of Matías Romero; dry, grassy plains and scattered clumps of scrubby trees and palms [41]. Collections were made in the vicinity of the village and at a rocky stream, 11 kilometers south on the Trans-isthmian Highway at an elevation of 230 m. Santo Domingo (Petapa).--Lat. 16° 50'; long. 95° 08'; elev. 225 m. A village about 13 kilometers west-southwest of Matías Romero; semi-arid scrub forest [37]. Sarabia.--Lat. 17° 04'; long. 95° 02'; elev. 100 m. A village 25 kilometers north of Matías Romero on the Trans-isthmian Highway; rainforest [32]. Collections were made in the vicinity of the village and in the rainforest along the Río Sarabia, 5 kilometers north of the village at an elevation of 80 meters. Tapanatepec.--Lat. 16° 32'; long. 94° 12'; elev. 90 m. A town on the Pan-American Highway on the lower slopes of the Sierra Madre de Chiapas; dense scrub forest [58]. Tehuantepec.--Lat. 16° 20'; long. 95° 14'; elev. 35 m. A large town on the Plains of Tehuantepec; scrub forest [61]. Collections were made in the vicinity of the town and in the dense scrub forest 8.6 kilometers west at an elevation of 85 meters and 14 kilometers west at an elevation of 120 meters. Tenango.--Lat. 16° 16'; long. 95° 30'; elev. 1100 m. A town in the mountains about 40 kilometers west-southwest of Tehuantepec; scrub forest [67]. Tequisistlán.--Lat. 16° 24'; long. 95° 37'; elev. 190 m. A village in the valley of the Río Tequisistlán, a tributary to the Río Tehuantepec; dense scrub forest [54]. Most collections were made about one kilometer north of the village where the Pan-American Highway crosses the Río Tequisistlán. Tolosita.--Lat. 17° 12'; long. 95° 03'; elev. 80 m. A village on the Río Tortuguero near the Trans-isthmian Highway; rainforest [30]. Tres Cruces.--Lat. 16° 26'; long. 95° 51'; elev. 750 m. A ranch near the Pan-American Highway, 70 kilometers by road west-northwest of Tehuantepec; dense scrub forest [49]. Tuxtepec--Lat. 18° 06'; long. 96° 05'; elev. 80 m. A town on the Río Papaloapan in northern Oaxaca; low evergreen forest [12]. Ubero.--Lat. 17° 18'; long. 95° 00'; elev. 80 m. A lumber camp and railroad station, 8.5 kilometers south of the Río Jaltepec on the Trans-isthmian Highway; rainforest [28]. Unión Hidalgo.--Lat. 16° 27'; long. 94° 48'; elev. 7 m. A village on the railroad, 20 kilometers east-northeast of Juchitán; open scrub forest [48]. Ventosa, La.--Lat. 16° 30'; long. 94° 51'; elev. 25 m. A village at the junction of the Pan-American and Trans-isthmian highways; open scrub forest [46]. Zanatepec.--Lat. 16° 28'; long. 94° 22'; elev. 80 m. A village on the Pan-American Highway at the eastern edge of the Plains of Tehuantepec; dense scrub forest [47]. Most collections were made in the scrub forest 5 to 8 kilometers west-northwest of the village. Zarzamora.--Lat. 16° 21'; long. 95° 48'; elev. 800 m. A ranch between La Reforma (16 kilometers west of Tequisistlán) and Santa María Ecatepec; scrub forest with oaks on higher ridges [59]. _Veracruz_ Acayucan.--Lat. 17° 57'; long. 94° 55'; elev. 160 m. A large town on the Trans-isthmian Highway; rainforest [21]. Collections were made in the vicinity of the town, but principally at Rancho Las Hojitas, 7 kilometers northwest of town at an elevation of 150 meters. Alvarado.--Lat. 18° 47'; long. 95° 47'; sea level. A fishing village at the mouth of the Río Papaloapan; coastal dunes and marshes [1]. Most collections were made 1-3 kilometers southeast of the village in marshes on the leeward side of the coastal dunes. Amatitlán.--Lat. 18° 26'; long. 95° 45'; elev. 4 m. A village on the bank of the Río Papaloapan; savanna and sugar plantations [6]. Aquilera.--Lat. 17° 48'; long. 95° 01'; elev. 150 m. A village 21 kilometers southwest of Acayucan on the Trans-isthmian Highway; rainforest [22]. Ayentes.--Lat. 18° 10'; long. 94° 26'; elev. 2 m. A railroad station on the east bank of the Río Coatzacoalcos, across the river from the city of Coatzacoalcos; scrub forest and marshes [17]. Berta.--Lat. 18° 07'; long. 94° 27'; elev. 5 m. A ranch just south of Coatzacoalcos; scrub and low evergreen forest [15]. Chacaltianguis.--Lat. 18° 18'; long. 95° 52'; elev. 5 m. A village on the Río Papaloapan; savanna [8]. Ciudad Alemán.--Lat. 18° 13'; long. 96° 07'; elev. 30 m. A new government town, headquarters of the Comisión del Papaloapan; scrub and low evergreen forest [10]. Coatzacoalcos (formerly Puerto México).--Lat. 18° 10'; long. 94° 27'; elev. 2 m. A seaport at the mouth of the Río Coatzacoalcos; scrub on coastal dunes; marshes and low evergreen forest inland [16]. Most collections are from the forest-savanna ecotone, 8 kilometers southwest of town. Cosamaloapan.--Lat. 18° 22'; long. 95° 50'; elev. 4 m. An agricultural town on the Río Papaloapan; savanna and sugar plantations [7]. Cosoleacaque.--Lat. 17° 59'; long. 94° 38'; elev. 55 m. A village 8 kilometers by road west of Minatitlán; savanna [19]. Cuatotolapam.--Lat. 18° 08'; long. 95° 16'; elev. 13 m. A village on the Trans-isthmian Railroad; savanna and low evergreen forest along streams [13]. Hueyapan.--Lat. 18° 08'; long. 19° 09'; elev. 85 m. A town 32 kilometers by road northwest of Acayucan; savanna and low evergreen forest [14]. Collections were made in the vicinity of the town and from forest 10 kilometers southeast of town at an elevation of 135 meters. Jesús Carranza (formerly Santa Lucrecia).--Lat. 17° 27'; long. 95° 02'; elev. 80 m. A town and railroad junction in the middle of the isthmus; rainforest [26]. Most of Dalquest's specimens came from varying distances from Jesús Carranza along the Río Coatzacoalcos and its tributaries. Minatitlán.--Lat. 17° 58'; long. 94° 32'; elev. 15 m. An oil refinery center on the Río Coatzacoalcos; savanna [20]. Naranjo.--Lat. 17° 35'; long. 95° 07'; elev. 100 m. A village on the Trans-isthmian Highway, 45 kilometers south of Acayucan; rainforest and palm forest [24]. Novillero.--Lat. 18° 16'; long. 95° 59'; elev. 10 m. A village on the Río Papaloapan; scrub forest and grassland [9]. Oaxaqueña, La.--Lat. 17° 26'; long. 94° 53'; elev. 80 m. A hacienda on the Río Coatzacoalcos about 12 kilometers east of Jesús Carranza; rainforest [27]. Playas, Río de las.--Lat. 18° 08'; long. 94° 07'; elev. 3 m. The river (sometimes known as the Río Tonolá) forming the boundary between the states of Veracruz and Tabasco; rainforest [18]. San Lorenzo.--Lat. 17° 44'; long. 94° 42'; elev. 25 m. A village on the Río Chiquito, about 30 kilometers southeast of Acayucan; rainforest [23]. Suchil.--Lat. 17° 31'; long. 95° 03'; elev. 40 m. A village on the Trans-isthmian Railroad, about 10 kilometers north of Jesús Carranza; rainforest [25]. Tecolapan.--Lat. 18° 24'; long. 95° 18'; elev. 275 m. A village on a small river of the same name in the western foothills of Los Tuxtlas; rainforest [5]. Tejada, Lerdo de.--Lat. 18° 37'; long. 95° 31'; elev. 60 m. An agricultural village, 35 kilometers by road east-southeast of Alvarado; scrub forest, marshes, and sugar plantations [2]. Collections were made in a marsh, 5 kilometers west-northwest of the village. Tlacotalpan.--Lat. 18° 37'; long. 95° 42'; elev. 3 m. A town at the confluence of the Río San Juan and Río Papaloapan; marshes and sugar plantations [3]. Tula.--Lat. 18° 36'; long. 95° 22'; elev. 150 m. A village near the western base of Los Tuxtlas; low evergreen forest and marshes [4]. Collections were made in a marsh 3 kilometers northwest of the village. THE AMPHIBIAN FAUNA OF THE LOWLANDS In presenting an account of the amphibian fauna of the lowlands of the Isthmus of Tehuantepec three items must be considered: 1. The composition of the fauna. 2. The ecology of the fauna. 3. The distribution of the fauna. These items, together with similar data concerning the amphibians of the adjacent highlands, will form the basis for the subsequent discussion of the establishment of present patterns of distribution in the isthmian region. _Composition of the Fauna_ The amphibian fauna of the lowlands of the Isthmus of Tehuantepec consists of 36 species definitely recorded from the area. These include one genus and species of caecilian, one genus, including three species of salamanders, and 14 genera and 32 species of anurans. In comparison with the known amphibian fauna of the forested and savanna portions of El Petén, Guatemala (Stuart, 1935 and 1958), we find that there are more species recorded from the isthmus than from El Petén. Stuart found only 20 species of amphibians in both forest and savanna habitats in El Petén. Of the 36 species of amphibians known from the isthmus, 28 occur on the Gulf lowlands and live in forest or savanna habitats. The geographic position of the isthmus with regard to major faunal areas in Middle America, and the diversity of the environment are important factors in understanding the presence of a large number of species of amphibians in the isthmus. The large number of species probably is a reflection of the diversity of the environment; this diversity is the result of fluctuation of climate, and thus environments, in the not too distant past. In no individual habitat, such as rainforest, savanna, or scrub forest, does the number of species approach the total for the region. _Ecology of the Fauna_ In the preceding section on the description of the Isthmus of Tehuantepec I have outlined the major environments in the region. With respect to the distribution of amphibians we may recognize three major environments in the isthmus--rainforest, semi-arid scrub forest, and savanna. Each of these has varying combinations of physical and biotic factors that are important in the ecology of amphibians. Because of the importance of moisture, not only for the maintenance of life in these animals, but in most species their dependence on water for breeding purposes, this environmental factor is considered the most significant in the ecological distribution of amphibians. A second factor is the availability of necessary shelter, especially aestivation sites. These factors will be compared in the three major environments in the region. Moisture is present in the environment in the form of free water or atmospheric moisture. With respect to the latter, it is well known that dense shaded forests have a considerably higher relative humidity than do open plains or areas with only scattered trees. Thus, the rainforests of the isthmus are characterized by a much higher relative humidity than are the savannas or semi-arid scrub forests. Although with regard to rainfall there is a pronounced dry season in the regions supporting rainforest, there still remains considerable atmospheric moisture in this environment throughout the year. The dense foliage provides shade and protection from desiccating effects of wind and sunlight; furthermore the foliage contributes moisture by transpiration. The deep alluvial soils mixed with large quantities of organic matter (decaying leaves and rotting logs) maintain considerable quantities of moisture. Conversely, the savannas and scrub forests have little atmospheric moisture during the dry season. In the former habitat there are few trees to provide shade or moisture through transpiration; in the latter most of the trees lose their leaves during the dry season. Thus, these environments are desiccated by the dry winds and direct sunlight. Furthermore, the soils in these environments become dry and caked. There is little or no terrestrial matter to hold moisture. Free water in these environments is present in a variety of forms at different times of the year. During the dry season the more extensive marshes in the savannas persist; many ponds and most of the streams in the rainforest are permanent throughout the year. In the scrub forest all except the largest streams become dry during the dry season, and no ponds exist through the dry season. With the advent of the first heavy summer rains the stream beds fill with water, marshes expand, and many depressions become ponds (Pl. 5, fig. 2). At this time the amount of free water in the scrub forests and savannas greatly increases, much more so than that in the rainforests. Environments are vertically stratified in the rainforests. There is the deep alluvial soil, the ground litter of leaves and decaying logs, the low bushes and small trees, and finally the tall trees of the forest. Each of these provides certain types of shelter for amphibians. The moist soil and litter on the forest floor is an important microhabitat for fossorial and strictly terrestrial species. The dense foliage of the trees, tree holes, and bromeliads growing on the trees provide shelter for arboreal species. Arboreal and terrestrial bromeliads and the terrestrial elephant-ear plants (_Xanthosoma_) contain water in the axils of their leaves throughout the year and thus provide an important habitat for amphibians. The low, spiny, deciduous trees of the scrub forest and the grasses and scattered trees in the savannas provide little shelter. In the savannas there are depressions, some of which contain water throughout the year; these are often surrounded by trees providing refugia for amphibians during the dry season. In the scrub forest many species congregate along streams and in moist stream beds during the dry season. Now that the important ecological factors of the major environments have been outlined, we may examine the local distribution of amphibians in each of these. Beginning with the rainforest, we find only one fossorial species, _Gymnopis mexicanus_. A large number of species are found on the forest floor; characteristic inhabitants of the leaf litter are: _Bufo valliceps_, _Eleutherodactylus rhodopis_, _Microbatrachylus pygmaeus_, and _Syrrhophus leprus_. Other terrestrial amphibians usually are not scattered throughout the rainforest, as are those named immediately above, but instead inhabit areas of forest adjacent to ponds or streams; these species include: _Bufo marinus_, _Eleutherodactylus natator_, _Eleutherodactylus rugulosus_, _Leptodactylus labialis_, _Leptodactylus melanonotus_, _Rana palmipes_ and _Rana pipiens_. The most striking ecological assemblage of amphibians in the rainforest is the arboreal group of species, including: _Bolitoglossa occidentalis_ _Bolitoglossa platydactyla_ _Eleutherodactylus alfredi_ _Hyla baudini_ _Hyla ebraccata_ _Hyla loquax_ _Hyla microcephala martini_ _Hyla picta_ _Phrynohyas modesta_ _Phrynohyas spilomma_ _Phyllomedusa callidryas taylori_ In the savannas _Rhinophrynus dorsalis_, _Engystomops pustulosus_, and _Gastrophryne usta_ are fossorial species. _Bufo marinus_, _Leptodactylus melanonotus_, _Leptodactylus labialis_, _Rana palmipes_, and _Rana pipiens_ are found in the vicinity of permanent water in the savannas. Although the savanna habitat does not provide the ecological conditions for the existence of an arboreal fauna, many arboreal species from the surrounding rainforest utilize the extensive marshes and ponds in the savannas for breeding purposes. Thus, _Hyla baudini_, _Hyla microcephala martini_, _Hyla picta_, and _Phrynohyas spilomma_ have been found breeding in savannas. In parts of savannas where clumps of trees surround depressions containing water throughout the year, individuals of the species named above, together with _Hyla loquax_ and _Phyllomedusa callidryas taylori_, may not only breed, but remain throughout the year. In the semi-arid scrub forest the same fossorial species as exist in the savannas are found. Likewise, _Bufo marinus_, _Leptodactylus labialis_, _Leptodactylus melanonotus_, and _Rana pipiens_ are found near permanent water. Terrestrial species in this semi-arid environment include _Bufo canaliferus_, _Bufo coccifer_, _Bufo marmoreus_, _Syrrhophus pipilans_, and _Diaglena reticulata_. Of these, _Syrrhophus pipilans_ sometimes inhabits low trees and bushes; the others may be fossorial. The arboreal species in the scrub forest include _Hyla baudini_, _Hyla robertmertensi_, _Hyla staufferi_, and _Phyllomedusa dacnicolor_. _Eleutherodactylus rugulosus_ and _Hylella sumichrasti_ live along streams in the scrub forest. _Hylella sumichrasti_ lays its eggs in these streams. In comparing the ecological differences in the amphibian assemblages in the three major habitats, the most obvious difference is the great percentage of arboreal species in the rainforest as compared with savanna and scrub forest. Only four arboreal species are found in the scrub forest, none in the savannas, but eleven in the rainforest. Likewise, there is an absence of ground-dwelling forms in the arid habitats; in the latter the only terrestrial species are those that are found near water. A possible exception is _Syrrhophus pipilans_. From the above analysis of ecological distribution we may see that the rainforest provides a variety of habitats for amphibians and that these habitats are suitable for amphibian life throughout the year. On the other hand, the savannas and scrub forests are characterized by extreme conditions of desiccation, a factor of considerable importance in limiting the ecological distribution of amphibians. However, there still is a diversity of amphibians in these semi-arid environments. Obviously, these species are adapted in various ways for survival during the dry season, at which time environmental conditions are such that the animals cannot carry on their normal activities. Although there is not an abundance of data concerning the seasonal activity of the fauna, what is available shows some interesting correlations with the environments. During the dry season in the scrub forest there is essentially no amphibian activity; an occasional _Rana pipiens_ may be seen along a river, or a _Bufo marinus_ may be seen at night. In the rainforest the terrestrial-breeding amphibians are active during the dry season. _Eleutherodactylus rugulosus_ is found at night or by day along streams. _Eleutherodactylus rhodopis_, _Microbatrachylus pygmaeus_, and _Bufo valliceps_ are active during the day; these plus _Bolitoglossa occidentalis_, _Bolitoglossa platydactyla_, _Eleutherodactylus alfredi_, _Eleutherodactylus natator_, and an occasional _Hyla_ are active at night. With the onset of the heavy summer rains and the subsequent formation of breeding ponds, amphibian activity reaches a peak. This is especially noticeable in the semi-arid environments, where during the dry season there is little activity. Among the anurans in the isthmus the four species of _Eleutherodactylus_, the two species of _Syrrhophus_, and the one species of _Microbatrachylus_ are either known, or presumed, to lay eggs on the ground; these develop directly into small frogs. All of the other anurans deposit their eggs in water or attach them to objects over water (_Phyllomedusa_); these hatch into tadpoles, which later metamorphose into frogs. _Hylella sumichrasti_ is known to breed only in streams. All of the other species breed in ponds, but at times some species deposit their eggs in streams; in this last group are _Bufo valliceps_, _Bufo marmoreus_, _Phyllomedusa callidryas taylori_, and _Rana pipiens_. Although the ecological data are incomplete, they do show that ecological conditions differ greatly in the three major environments, different species of amphibians inhabit these environments, and that the fauna is ecologically diversified in each environment. _Distribution of the Fauna_ Plotting the distributions of species of amphibians known to live in the lowlands of the Isthmus of Tehuantepec results in an array of geographic patterns. These may be analyzed with respect to those species that are restricted either to the Gulf lowlands or the Pacific lowlands, or those that occur on both the Gulf and Pacific lowlands. Furthermore, the distributions may be analyzed with respect to those species whose ranges extend from México across the Isthmus of Tehuantepec into Central America, those that reach the isthmus from Central America but do not extend into México proper, and those that reach the isthmus from México but do not extend into Central America. It should be kept in mind that the following analysis is of the lowland inhabitants only. Species inhabiting the foothills and mountains will be discussed later. 1. SPECIES RESTRICTED TO THE GULF LOWLANDS. Of the 36 species of amphibians recorded from the Isthmus of Tehuantepec, nine (25 per cent) are in this group. Four of these (_Eleutherodactylus alfredi_, _Syrrhophus leprus_, _Hyla loquax_, and _Hyla picta_) live in the Gulf lowlands to the east and to the west of the isthmus. Three others (_Hyla ebraccata_, _Hyla microcephala martini_ and _Phyllomedusa callidryas taylori_) are primarily Central American in their distribution and reach the northwestern limits of their ranges in the Gulf lowlands of the isthmus, whereas _Bolitoglossa platydactyla_ and _Eleutherodactylus natator_ reach the southern limits of their distributions in the isthmus. 2. SPECIES RESTRICTED TO THE PACIFIC LOWLANDS. This group includes six species, or 17 per cent of the amphibian fauna of the isthmus. Two of these (_Bufo coccifer_ and _Syrrhophus pipilans_) range to the east and to the west of the isthmus on the Pacific lowlands. Two others (_Bufo canaliferus_ and _Hyla robertmertensi_) range from the isthmus into Central America, and _Diaglena reticulata_ and _Phyllomedusa dacnicolor_ range on the Pacific lowlands of México southeastward to the isthmus. 3. SPECIES THAT OCCUR ON THE PACIFIC AND GULF LOWLANDS. This group includes 19 species, or 53 per cent of the total amphibian fauna. Of these, nine species (25 per cent of the entire amphibian fauna) are widespread throughout the lowlands of México and Central America; these are: _Gymnopis mexicanus_ _Rhinophrynus dorsalis_ _Bufo marinus_ _Engystomops pustulosus_ _Leptodactylus labialis_ _Leptodactylus melanonotus_ _Hyla baudini_ _Hyla staufferi_ _Rana pipiens_ Four species occur on the Gulf lowlands to the east and to the west of the isthmus, but on the Pacific lowlands they occur only to the east; this group includes _Bufo valliceps_, _Eleutherodactylus rhodopis_, _Phrynohyas modesta_, and _Phrynohyas spilomma_. Three species live to the east and to the west of the isthmus on the Pacific lowlands, but only to the west on the Gulf lowlands; these include _Eleutherodactylus rugulosus_, _Microbatrachylus pygmaeus_, and _Gastrophryne usta_. Six species that cross the isthmus live on the humid Gulf lowlands and on the humid lowlands of Chiapas and Guatemala, but not on the semi-arid Plains of Tehuantepec; these include _Bolitoglossa occidentalis_, _Eleutherodactylus rhodopis_, _Microbatrachylus pygmaeus_, _Phrynohyas modesta_, _Phrynohyas spilomma_, and _Rana palmipes_. Of these, _Microbatrachylus pygmaeus_ also occurs in scattered humid environments to the west of the isthmus on the Pacific lowlands. Two species are endemic to the isthmian region. _Bolitoglossa veracrucis_ is known only from the humid northern slopes of the isthmus. _Hylella sumichrasti_ occurs on the Pacific slopes of the isthmus and extends to the east into western Chiapas. In analyzing the distribution of the amphibians with respect to those that are restricted to either the Pacific or Gulf lowlands or those that cross the continental divide in the isthmus, we find that 25 per cent of the species are restricted to the Gulf lowlands, 17 per cent are restricted to the Pacific lowlands, and 53 per cent cross the isthmus. In analyzing the distribution patterns with respect to those that extend across the isthmus of Tehuantepec from east to west, we find that 14 per cent of the species do not extend east of the isthmus into Central America and that 19 per cent do not range west of the isthmus into México proper; 61 per cent of the species range to the east and to the west of the isthmus. Of the 36 species of amphibians inhabiting the isthmus only nine species (25 per cent) range across the isthmus, that is, occur on the Gulf and Pacific lowlands, and also range to the east and to the west of the isthmus. To these wide-ranging species the diversified environments of the isthmus do not present a barrier to distribution. The other 27 species (75 per cent) either do not cross the isthmus from east to west or from north to south; thus, probably in one way or another the isthmus presents a barrier to their distribution. THE AMPHIBIAN FAUNA OF THE FOOTHILLS AND ADJACENT HIGHLANDS To amphibians inhabiting the foothills and mountains of southern México and northern Central America, the isthmus presents a great barrier to dispersal. For example, salamanders of the genus _Thorius_, the _mexicanus_ and _augusti_ groups of the genus _Eleutherodactylus_, the _bistincta_ group of the genus _Hyla_, and the genus _Tomodactylus_ occur on the Mexican Plateau and southward into the mountains of Oaxaca. Nevertheless, no members of these groups are present in the Guatemalan-Chiapan Highlands. The genera _Chiropterotriton_, _Magnadigita_, _Pseudoeurycea_, and _Ptychohyla_, as well as the _eximia_ group of _Hyla_ are represented by different species in the Guatemalan-Chiapan Highlands than in the mountains of México on the other side of the isthmus. Several species of _Plectrohyla_ occur in the Guatemalan-Chiapan Highlands, but none is known from the Mexican Highlands, although one species occurs in the Tuxtlas. Living in the humid forests of the foothills are salamanders of the genus _Lineatriton_, frogs of the _spatulatus_ group of _Eleutherodactylus_, _Anotheca coronata_, _Hyla miotympanum_, and _Phyllomedusa moreleti_. All of these occur in the foothills of the Sierra Madre Oriental in eastern México and in Los Tuxtlas. _Lineatriton_, _Hyla miotympanum_, and the _spatulatus_ group of _Eleutherodactylus_ do not occur in the foothills of the Guatemalan-Chiapan Highlands; those amphibians reach the end of their ranges at the isthmus. _Phyllomedusa moreleti_ and _Anotheca coronata_ are found in the northern foothills of the Guatemalan-Chiapan Highlands, and _Phyllomedusa moreleti_ is found in the foothills on the Pacific slopes of the Chiapan Highlands. Although the above analysis is not so detailed as that of the lowland inhabitants, it does show that all of the genera and species of amphibians known to inhabit the foothills and highlands adjacent to the isthmus, only two species of amphibians cross the isthmus from one highland mass to the other. Thus, it is evident that the Isthmus of Tehuantepec presents a great barrier to dispersal of these groups of amphibians. ESTABLISHMENT OF PRESENT PATTERNS OF DISTRIBUTION From the foregoing analysis of geographical and ecological distribution in the Isthmus of Tehuantepec we may strive for an interpretation of the events that led to the establishment of patterns of distribution displayed not only by the amphibians, but other terrestrial vertebrates as well. The thesis that I am proposing below is based on the premise that in southern México and northern Central America climatic fluctuation during the Pleistocene was of sufficient magnitude to cause vegetational shifts, both vertically and latitudinally, resulting in the establishment of alternating continuous and discontinuous lowland and highland environments, although this climatic fluctuation was not so great as to eliminate tropical lowland environments from the region. I feel that the present patterns of distribution of the amphibians in the Isthmus of Tehuantepec may be explained on this premise. Many authors dealing with the herpetofauna of Middle America have followed Schuchert's (1935) suggestion of a seaway in the isthmus during the Cenozoic. Thus, Burt (1931), Duellman (1956, 1958a), Gloyd (1940), Oliver (1948), Smith and Laufe (1946), and Stuart (1941) employed the presence of a seaway to explain distribution and speciation in various genera. Durham, Arellano, and Peck (1952), Olson and McGrew (1941), and Stirton (1954) have provided geological evidence that there probably was no Cenozoic seaway in the Isthmus of Tehuantepec. Even if there were a seaway in the Pliocene or Miocene (the dating of this possible seaway is open to question), its presence is not necessary to explain the present patterns of distribution in the isthmus. In recent years the study of natural biotic environments, palynology, and Pleistocene chronology in Middle America has produced a wealth of data, which although still fragmentary begins to form a picture of past climatic events in that part of the world. Sedimentary studies by Hutchinson, Patrick, and Deevey (1956) and Sears, Foreman, and Clisby (1955) have provided evidence of drastic climatic shifts in México during the Pleistocene. Further evidence of bioclimatic fluctuation is provided by Martin and Harrell (1957) and Martin (1958); the latter has suggested that there was a displacement of the tropical zones in southern México and northern Central America by as much as 3000 feet during the glacial maximum. Much of the evidence of such drastic vertical shifts in environments is based on the presence of Pleistocene montane glaciers on Mexican volcanoes (White, 1956) and Chirripo in Costa Rica (Weyl, 1955). Dorf (1959) supports this idea of drastic climatic change. In his studies of the avifauna of México and Guatemala Griscom (1932 and 1950) made an important issue of the continuity of the bird fauna in what he called the Subtropical Life-zone, which essentially consists of cloud forest, a widespread, but discontinuous, habitat on the Gulf (windward) slopes of the Mexican and Central American highlands at elevations between 1000 and 2000 meters. To account for this apparent uniformity in the avifauna Griscom hypothesized a continuity of cloud forest environment in the Pleistocene; this would result in the depression of cloud forests to the coastal lowlands and the displacement of tropical lowland environments far to the south in Central America. Stuart (1951) objected to this displacement of lowland tropical rainforest; he stated that a descent to sea level of a subtropical zone would have brought about either widespread extermination of the tropical fauna or acclimatization of that fauna to subtropical conditions. Although palynological studies and some faunal studies of subtropical and temperate animals suggest a drastic climatic fluctuation that might have eliminated tropical environments in southern México and northern Central America, there is much biological evidence indicating the existence of tropical environments in this region even during the glacial maximum. Especially significant is the diversity of species inhabiting the present tropical environments; many of these have differentiated from related taxa to the south. In the Pleistocene, climate fluctuated and vegetation shifted correspondingly in southern México and northern Central America. Most of the palynological studies and many studies of Pleistocene chronology deal with montane regions, either the Mexican Plateau or the mountains rising from the plateau. No such studies have been made in lowland tropical environments. During glacial advances the tropical lowland environments in México probably were not eliminated, for the great diversity of animals in these environments supports the hypothesis that they have been in existence for some time, although periodically they may have been discontinuous. In order to understand the nature of bioclimatological events in the Pleistocene in lowland tropical environments of southern México, certain factors that are of little importance in the interpretation of Pleistocene chronology in the highlands must be considered. These factors are: 1) climatic moderation by oceans, 2) fluctuation in sea level, and 3) fluctuation in level of the water table as affected by sea level. It is well-known that large bodies of water moderate the temperature on adjacent land. Furthermore, it is known that faunas of marine invertebrates shifted latitudinally in the Pleistocene; Trask, Phleger, and Stetson (1947) recorded cold-water Foraminifera then as far south as the Sigsbee Deep in the middle of the Gulf of Mexico. Large bodies of warm water, such as the Gulf of Mexico, Caribbean Sea, and Pacific Ocean of today, probably were not sufficiently cooled at the time of glacial advance to affect greatly the temperature of the winds blowing across them. Even if these bodies of water were somewhat cooler than now, the prevailing winds blowing from them onto the lowlands of México and northern Central America would have aided in maintaining relatively high temperatures there. These warm winds probably counteracted the cooling effect of glaciation in the lowlands and thereby maintained tropical conditions near the seas. Although no adequate studies of Pleistocene beach lines have been made in southern México, such information is available for peninsular Florida on the other side of the Gulf of Mexico (Cooke, 1945). Fluctuation in sea level in the Pleistocene has been used by Hubbell (1954), Goin (1958), and Duellman and Schwartz (1958) to explain present patterns of distribution of animals in Florida. If Cooke's interpretations can be applied to the western side of the Gulf of Mexico, even generally, it would be supposed that sea level varied from about 300 feet lower than at present during the Illinoian Glacial Period to about 275 feet higher than at present during the Aftonian Interglacial Period. Lowering of sea level would expand the lowlands in the isthmus; rising sea level would restrict them, leaving only the central ridges and many islands in the isthmus, but never forming a seaway between the Gulf of Mexico and the Pacific Ocean. Probably the level of the water table in the coastal lowlands and the gradients of the streams in the lowlands and foothills was closely correlated with fluctuation in sea level. If sea level fluctuated as much as 575 feet in the Pleistocene, changes in the level of the water table must have been of considerable magnitude. During times of glacial advances the lowlands of the isthmus probably were more extensive and had more semi-arid tropical environments than at present, with patches of rainforest existing in sheltered valleys along the major streams. In the course of bio-climatic fluctuation the semi-arid environments (scrub forest and/or savanna) were continuous at times from the Pacific lowlands across the isthmus to the Gulf lowlands. At those times such typical inhabitants of the semi-arid environments as _Rhinophrynus dorsalis_, _Engystomops pustulosus_, and _Hyla staufferi_ could have made their way across the isthmus. At times of most extensive glaciation, such as the Illinoian, temperatures in the isthmus probably were low enough to permit the growth of pine-oak forest and cloud forest continuously across the central ridges from the Mexican to the Chiapan-Guatemalan highlands. At those times such highland members of the fauna as _Chiropterotriton_, _Pseudoeurycea_, _Magnadigita_, and the _eximia_ group of _Hyla_ could have crossed the isthmus. During Wisconsin time, climate probably fluctuated less than during previous glaciations; probably no montane environments, except cloud forest, were represented in the isthmus during the Wisconsin. Even at this relatively late date such animals as _Lineatriton lineola_, _Anotheca coronata_, and _Phyllomedusa moreleti_ could have crossed the isthmus. During the interglacial periods, which in the isthmian region were characterized by warmer temperatures, higher sea level and consequently more restricted areas of lowlands, and possibly more rainfall than in the glacial periods, the continuity of pine-oak forest and cloud forest from east to west across the isthmus was interrupted. Probably, too, the semi-arid environments were restricted, and the rainforests were more widespread. At those times animals now inhabiting the rainforests of the Gulf lowlands and those inhabiting the Pacific lowlands of Chiapas and Guatemala could have crossed the isthmus. In this group are species such as _Bolitoglossa occidentalis_, _Eleutherodactylus rhodopis_, _Microbatrachylus pygmaeus_, and _Rana palmipes_. The amount of differentiation in isolated populations of amphibians in southern México and northern Central America gives some idea of relative lengths of time of isolation from related populations. Those populations inhabiting high mountain environments on either side of the isthmus are specifically distinct. Some populations inhabiting cloud forests lower on the mountains are specifically distinct from related populations on the other side of the isthmus; between others there is no recognizable differentiation. Even though many populations are isolated from other populations of the same species in the lowlands of the isthmus, there is no apparent speciation. This indicates that the lowland environments and their inhabitants have been isolated from one another for a shorter time than have the highland environments and their inhabitants. ACCOUNTS OF SPECIES For each species of amphibian known to occur in the lowlands of the Isthmus of Tehuantepec, localities where one or more specimens were collected are listed, and variation, ecology, and life histories are discussed. A total of 2833 specimens has been examined for the purposes of this study. Individual specimens cited in the text are listed with catalogue numbers and abbreviations of the name of the museum, as follows: AMNH American Museum of Natural History KU University of Kansas Museum of Natural History MCZ Museum of Comparative Zoology, Harvard College UIMNH University of Illinois Museum of Natural History UMMZ University of Michigan Museum of Zoology USNM United States National Museum =Gymnopis mexicanus mexicanus= Duméril and Bibron _Oaxaca_: El Barrio (3); Matías Romero; Tehuantepec (2). _Veracruz_: Cosamaloapan; Cuatotolapam (2). The two specimens from Cuatotolapam were collected by Ruthven in an area of mixed savanna and forest. The three specimens (USNM 30535-7) listed above from El Barrio were collected by Sumichrast; possibly they came from another locality. The city of Tehuantepec is divided into seven districts called "barrios." The two specimens listed from Tehuantepec (MCZ 1604) merely bear the data "Tehuantepec, Mexico." They may have come from the town, the district, or from anywhere in the isthmus. The specimen from Matías Romero has 109 primary and 67 secondary annuli, a length of 400 mm., and a diameter of 19 mm.; the one from Cosamaloapan has 106 primary and 58 secondary annuli, a length of 397 mm., and a diameter of 19 mm. Data on the other specimens were recorded by Dunn (1942:475). =Bolitoglossa occidentalis= Taylor _Oaxaca_: Río Sarabia (2); Ubero. _Veracruz_: La Oaxaqueña; 14 km. E of Suchil. The specimens from Oaxaca are only tentatively assigned to _occidentalis_. All are immature and lack maxillary teeth. Taylor (1941:147) stated that the maxillary teeth are absent in young _occidentalis_. One from Río Sarabia is a male with a body-length of 29 mm. and a tail-length of 22 mm. The dorsum is reddish brown streaked with dark gray; the venter is dark gray. Two small individuals (one from Sarabia and one from Ubero) have body-lengths of 19 and 21 mm. and tail-lengths of 10.5 and 11 mm. In life they were pale yellowish tan above with a brown triangular mark on the occiput, but with no middorsal stripe. Both were found in the axils of elephant ear plants (_Xanthosoma_). This species has been noted by Goodnight and Goodnight (1956:146) on the Atlantic lowlands at Palenque, Chiapas, and by Shannon and Werler (1955:362) at several localities in Los Tuxtlas, Veracruz. I have collected it at Vista Hermosa on the eastern slopes of the Sierra Madre Oriental above Tuxtepec in northern Oaxaca. Both _B. occidentalis_ and _B. rufescens_ have been reported from Palenque, Chiapas (Taylor and Smith, 1945:547). Reëxamination of specimens from northern Chiapas and Tabasco is needed to verify the sympatric occurrence of these two similar species. =Bolitoglossa platydactyla= Tschudi _Oaxaca_: La Oaxaqueña; Tolosita (2). _Veracruz_: Acayucan; Cuatotolapam; 25 km. ESE of Jesús Carranza; 14 km. E of Suchil; 2.7 km. N of Tula. Known only from the Gulf lowlands in the isthmian region, this species has been taken in a variety of habitats within the humid forest area: under outer leaves of banana plants, under a rock along a stream, under a log in a plowed field, and on a reed in a pond at night. Three adult males have an average snout-vent length of 44 mm. and a tail-length of 41 mm. In life the color of the dorsum varied from orange-yellow to orange-tan, usually being more orange on the tail. The iris was a reddish orange. =Bolitoglossa veracrucis= Taylor _Veracruz_: 35 km. SE of Jesús Carranza (21). This species is known only from the type series collected at night on a limestone cliff by Walter W. Dalquest. If this salamander is restricted to this type of habitat, it should be found in the region of extensive limestone outcroppings in northern Chiapas and southern Tabasco. =Rhinophrynus dorsalis= Duméril and Bibron _Oaxaca_: Ixtepec; Limón; Salina Cruz (18); Tehuantepec (57); Tuxtepec (3). _Veracruz_: Amatitlán (3); Cosamaloapan (5); Novillero (2); San Lorenzo. This species inhabits the scrub forests of the Pacific coastal plain and the savannas in southern Veracruz; apparently it does not occur in rainforest. Consequently, its distribution in the isthmus is discontinuous. PLATE 1 [Illustration: FIG. 1. Savanna about 75 kilometers east of Coatzacoalcos, Veracruz. Photograph by L. C. Stuart.] [Illustration: FIG. 2. Low scrub forest near Alvarado, Veracruz. Photograph by L. C. Stuart.] PLATE 2 [Illustration: FIG. 1. Rainforest near Tolosita, Oaxaca. March, 1956.] [Illustration: FIG. 2. Rainforest along the Río Sarabia, Oaxaca. March, 1956.] PLATE 3 [Illustration: FIG. 1. Transition forest near La Princesa, Oaxaca. March, 1956.] [Illustration: FIG. 2. Palm Savanna on the Plains of Chivela, Oaxaca. March, 1956.] PLATE 4 [Illustration: FIG. 1. Scrub forest on the Plains of Tehuantepec in dry season. March, 1956.] [Illustration: FIG. 2. Scrub forest on the Plains of Tehuantepec in rainy season. View toward the north. In the distance is the Continental Divide in the hills of the Isthmus. July, 1958.] PLATE 5 [Illustration: FIG. 1. Low, dense scrub forest near La Ventosa, Oaxaca. July, 1958.] [Illustration: FIG. 2. Temporary pond in scrub forest north of Salina Cruz, Oaxaca. July 7, 1958. _Rhinophrynus dorsalis_, _Bufo marmoreus_, and _Diaglena reticulata_ were breeding here the previous night.] PLATE 6 [Illustration: FIG. 1. Calling male of _Rhinophrynus dorsalis_, photographed in a pond north of Santa Cruz, Oaxaca, on July 6, 1958. × 2/3.] [Illustration: FIG. 2. Color pattern variation in two adults of _Bufo canaliferus_ from Juchitán, Oaxaca. × 2/3.] PLATE 7 [Illustration: FIG. 1. Calling male of _Engystomops pustulosus_, photographed in a pond west of Tehuantepec, Oaxaca, on July 5, 1956. × 2.] [Illustration: FIG. 2. Foamy egg mass of _Engystomops pustulosus_ at the edge of a pond west of Tehuantepec, Oaxaca. July 5, 1956. × 3/8.] PLATE 8 [Illustration: FIG. 1. Calling male of _Diaglena reticulata_, photographed at a pond north of Salina Cruz, Oaxaca, on July 6, 1958. × 1/2.] [Illustration: FIG. 2. Clasping pair of _Diaglena reticulata_ at the edge of a pond north of Salina Cruz, Oaxaca, on July 6, 1958. × 1.] Breeding congregations were found after heavy rains at Tehuantepec on July 5, 1956, at Cosamaloapan, Novillero, and Amatitlán on July 26, 1956, and at Salina Cruz on July 6, 1958. The call is a long "worrp" made while the male is floating on the surface of the pond. The small heads, small limbs, and greatly inflated bodies cause the calling males to resemble miniature caricature balloons (Pl. 6, fig. 1). Amplexus is inguinal. These toads are notably wary, even when calling. Often the beam of a flashlight or the slightest disturbance of the water will cause the males to stop calling. The body is deflated with one last nauseous note, and the frog sinks beneath the surface of the water and swims away with short slow kicks of the hind feet. =Bufo canaliferus= Cope _Oaxaca_: Chivela; Salina Cruz; Santa Efigenia; Tapanatepec (6); Tehuantepec (10); Zanatepec (4). This small toad apparently is restricted to the Pacific lowlands from the Isthmus of Tehuantepec eastward to Guatemala. At Zanatepec on July 13, 1956, males were calling from a flooded field bordered by scrub forest. The call is a rather loud nasal racket. Living individuals vary greatly in coloration. Some have yellowish tan flanks and dorsum and an orange middorsal stripe; others have a pale red dorsum, yellow flanks, and a cream middorsal stripe (Pl. 6, fig. 2). =Bufo coccifer= Cope _Oaxaca_: Juchitán (5); Tehuantepec. It is with some degree of hesitancy that these toads are referred to the species _coccifer_. Although these and other specimens from Guerrero and Michoacán display no striking differences from specimens from Costa Rica, Nicaragua, and southeastern Guatemala, the ranges of the populations are separated by a broad hiatus in Chiapas and Guatemala. Possibly this species has utilized the sub-humid corridor through northern Central America (Stuart, 1954) and subsequently disappeared from the corridor in Guatemala and Chiapas. Specimens of a _coccifer_-like toad collected by Stuart in the vicinity of Jacaltenango, Departamento Huehuetenango, Guatemala, are much larger than either the Central American or Mexican specimens of _coccifer_. A final commitment on the systematic status must await a thorough study of this group of toads. Males of this species were calling from a grassy rain-pool in open scrub forest at the edge of Juchitán on July 6, 1956. The call is a low "whirrr." The calling males were sitting in the shallow water at the edge of pond, where they were hidden by the grass. None was observed in open water, as is characteristic of calling males of _Bufo canaliferus_ and _marmoreus_. =Bufo marinus= Linnaeus _Oaxaca_: Agua Caliente; Guichicovi (3); Mixtequilla; Tolosita (6); Tehuantepec (37); Tuxtepec; Unión Hidalgo. _Veracruz_: Ciudad Alemán (4); Cosamaloapan; Cuatotolapam (19); 20 km. SE of Jesús Carranza (4); 38 km. SE of Jesús Carranza (10); 20 km. NE of Jesús Carranza (4); Novillero. This large toad is abundant throughout the lowlands of the isthmus. The loud rattling call of males was heard on rainy nights throughout the summer. In March, 1956, several adults were found in a small cave back of a spring at Agua Caliente. =Bufo marmoreus= Wiegmann _Oaxaca_: Cerro San Pedro (2); Chivela (5); Escurano (3); Juchitán; Salina Cruz (101); Santa Lucía (2); 12 km. S of Santiago Chivela (11); Santo Domingo; Tapanatepec; Tehuantepec (100); Tequisistlán. _Veracruz_: Alvarado; Coatzacoalcos. This toad is abundant on the Pacific lowlands, where it inhabits both open and dense scrub forest. On the Gulf lowlands its distribution seems to be limited to xeric coastal habitats. Aside from the specimens from Alvarado and Coatzacoalcos, it is known in Veracruz only from Boca del Río (Langebartel and Smith, 1959:27). The similarity in size of _Bufo marmoreus_ and _valliceps_ and their almost completely allopatric ranges suggest that the two species may be in competition at any one locality. Nevertheless, both were calling from a small rocky stream south of Santiago Chivela on July 6, 1956. On the night of July 6, 1958, an estimated 400 toads of this species made up a breeding congregation near Salina Cruz. The site was a shallow muddy pond about 20 × 40 meters located in an area cleared of scrub forest; the banks of the pond were devoid of vegetation (Pl. 5, fig. 2). Breeding in the same pond were _Rhinophrynus dorsalis_ and _Diaglena reticulata_. The following morning no more than a dozen _Bufo_ were found in the pond, but several individuals were found beneath debris and in small burrows near the pond. On July 7, 1958, large numbers of tadpoles and recently metamorphosed young were in a shallow grassy pool just east of Salina Cruz. Taylor (1943b:347) referred certain specimens from Tehuantepec to _Bufo perplexus_, a species closely related to _Bufo marmoreus_. Evidence to be presented elsewhere shows that _perplexus_ does not occur in the isthmus. =Bufo valliceps valliceps= Wiegmann _Oaxaca_: Guichicovi (2); Matías Romero; 32 km. N of Matías Romero (2); Nueva Raza; Río Sarabia (3); Santa María Chimalapa (14); Santiago Chivela; 12 km. S of Santiago Chivela (5); Santo Domingo (5); Tolosita (7). _Veracruz_: Acayucan (3); Alvarado; Amatitlán; Ayentes; Cosamaloapan (3); Cosoleacaque (6); Cuatotolapam (14); Hueyapan; 20 km. ENE of Jesús Carranza (6); 20 km. S of Jesús Carranza; 25 km. SE of Jesús Carranza (23); 35 km. SE of Jesús Carranza; 60 km. SW of Jesús Carranza (5); La Oaxaqueña (4); Novillero (4); San Lorenzo (5). Individuals were found in both wet and dry seasons. In the dry season they were most frequently found in rainforest, whereas in the rainy season breeding congregations were found in savannas as well. This toad occurs throughout the Gulf lowlands and on the Pacific slopes and in the Grijalva Valley of Chiapas and Guatemala, but not on the Pacific lowlands of the isthmus. I have not been able to recognize individuals referrable to the race _macrocristatus_. Firschein and Smith (1957:219) described _macrocristatus_ from the mountains of eastern Oaxaca and referred to it specimens from the Gulf lowlands of northern Chiapas. None of the present material shows the hypertrophied cranial crests supposedly characteristic of _macroaristatus_, nor do specimens from the isthmus resemble the population in the Grijalva Valley being described by L. C. Stuart, who will discuss the variation in, and the validity of, the named populations of _valliceps_. Five specimens from San Lorenzo, Veracruz (USNM 123516-20), were identified as _Bufo cristatus_ by Smith (1947:408). Firschein (1950:83) redefined the _cristatus_ group of _Bufo_ and assigned these specimens to _valliceps_. =Eleutherodactylus alfredi= Boulenger _Oaxaca_: Tolosita (2). _Veracruz_: 35 km. SE of Jesús Carranza (6). These specimens were collected in rainforest. Shreve (1957:247) pointed out the close resemblance between _E. alfredi_ and _E. conspicuus_ from Piedras Negras, Guatemala, and treated them as subspecies. Examination of the specimens from the isthmus, together with seven from central Veracruz and one from Teapa, Tabasco, suggests an even closer relationship. _Eleutherodactylus conspicuus_ was diagnosed by Taylor and Smith (1945:567) as differing from _alfredi_ "in lacking a tarsal fold, in having shorter hind legs with the tibiotarsal articulation reaching only to the nostril instead of beyond the tip of the snout; the vomerine teeth barely reach the posterior level of the choanae." The specimen from Teapa has the vomerine teeth reaching to the posterior edge of the choanae; in the eight specimens from the isthmus the teeth reach the posterior edge of the choanae in two and to the middle of the choanae in six; in seven specimens from central Veracruz the teeth reach the posterior edge of the choanae in two and to the middle in five. The tibiotarsal articulation extends beyond the tip of the snout in the specimen from Teapa and in two from central Veracruz; in three specimens from the isthmus and in one from central Veracruz it extends only to the nostril; in the others it extends to the snout. The tarsal fold is absent in the specimen from Teapa, in three from the isthmus, and in all those from central Veracruz; it is weakly present in the others. In the light of this evidence there seems to be little justification in recognizing two species or even two subspecies in this group. Consequently, _Eleutherodactylus conspicuus_ Taylor and Smith (1945) is here placed in the synonymy of _Eleutherodactylus alfredi_ Boulenger (1898), a species with a range extending from Cuautlapan and Potrero Viejo in central Veracruz southward and eastward in forested habitats to western El Petén, Guatemala. =Eleutherodactylus natator= Taylor _Veracruz_: 35 km. SE of Jesús Carranza (3); 38 km. S of Jesús Carranza; 55 km. SE of Jesús Carranza. The snout-vent length is 42.0 mm. in a male and averages 59.5 mm. in three adult females. The tarsal fold is low and extends about half the length of the tarsus; the first and second fingers are subequal in length; the tibiotarsal articulation extends beyond the tip of the snout. The patches of vomerine teeth lie between the posterior margins of the choanae. The throat and belly are immaculate, and the soles of the feet are dark. In the isthmus this species can be distinguished from _Eleutherodactylus rugulosus_ by less rugose skin on the dorsum and absence of dark ventral mottling. The specimens reported here extend the known range of _natator_ eastward from Camotlán, Oaxaca; northward in Veracruz the species inhabits foothills as far north as Huatusco. =Eleutherodactylus rhodopis= Cope _Oaxaca_: 30 km. N of Matías Romero; Río Sarabia (5); Tapanatepec (87); Tolosita (6); between Zanatepec and Tapanatepec. _Veracruz_: 25 km. SE of Jesús Carranza; 35 km. SE of Jesús Carranza (2); 22 km. SSW of Jesús Carranza; 20 km. ENE of Jesús Carranza (7); Minatitlán; Tapalapan (5). For the purposes of the present study I am not recognizing _Eleutherodactylus beati_, _E. dorsoconcolor_, and _E. venustus_ as specifically, or even subspecifically distinct from the earlier named _E. rhodopis_. Probably these are mere color varieties of a single species. In the dry season frogs of this species were in humid forests, where they were most frequently found along small streams and in ravines. The species is widespread in the Gulf lowlands, but does not occur on the Plains of Tehuantepec. It does inhabit the Pacific slopes on the foothills of the Sierra Madre de Chiapas, the western part of which extends into eastern Oaxaca near Tapanatepec. =Eleutherodactylus rugulosus= Cope _Oaxaca_: La Princesa (30); Modelo; Santa Lucía (10); Tapanatepec (26); Tehuantepec (6); Tres Cruces (8). _Veracruz_: Tapalapan (5). In addition to the specimens from the lowlands of the isthmus, for the purposes of the following discussion, I have included data on two specimens from the southern slopes of the Sierra del Sur in Oaxaca (Mirador and Chacalapa) and on several specimens from Los Tuxtlas in Veracruz (Los Chaneques, 67; Salto de Eyipantla, 35; and San Andrés Tuxtla, 11). Frogs of the _Eleutherodactylus rugulosus_ complex occur from southern Veracruz and Sinaloa southward through Central America. Taylor (1940:401) described _E. vocalis_ from Hacienda El Sabino, Michoacán; Taylor and Smith (1945:580) described _E. avocalis_ from Tres Cruces, Oaxaca. These have been considered as species distinct from _rugulosus_, which is known to occur in Veracruz, Guerrero, and Chiapas southward into Central America. Although the large number of specimens collected in the isthmus does not aid in defining the ranges of the taxa involved, these specimens do give some idea of the variation in certain characters in a given population. In specimens from Los Tuxtlas the tarsal fold is well-developed and extends two-thirds to three-fourths the length of the tarsus; the tibiotarsal articulation reaches the nostril and sometimes slightly beyond the tip of the snout. In males the tympanum is nearly equal to the diameter of the eye; in females it is about one-half the diameter of the eye. The posterior surfaces of the thighs are dark brown or black with whitish or cream-colored spots, flecks, or irregular mottling. The tarsal fold is dark; the throat is pale in some individuals, but in most is mottled with dark brown or gray flecks. Individuals from La Princesa near the continental divide in Oaxaca show the same variation in body proportions and development of the tarsal fold. The posterior surfaces of the thighs are dark brown indistinctly mottled with lighter brown. The throat is dark brown. Specimens from the Pacific slopes of Oaxaca, including the Plains of Tehuantepec, have dark brown thighs mottled with dusty cream. The tibiotarsal articulation extends slightly beyond the tip of the snout in all specimens. In males the tympanum is equal to about two-thirds the diameter of the eye. Duellman (1958b:6) discussed the variation in these characters in populations in Colima, Jalisco, and Michoacán. Until the extent of variation of these characters is known throughout the range of _rugulosus_, the recognition of populations either as species or subspecies seems superfluous. Consequently, I have used the oldest name; this does not necessarily imply, however, that all populations of _rugulosus_ (_sensu lato_) are conspecific. Of the 200 specimens examined, 15 have a middorsal stripe that is red or yellow. The iris varies from a copper to a dark golden color and shines bright red at night. Many of the specimens are juveniles; these were collected in the dry season, at which time they were found beneath rocks along streams, in road culverts where there was some water, and in holes in banks and cliffs. =Microbatrachylus pygmaeus= Taylor _Oaxaca_: La Princesa (5); Matías Romero (9); Río Sarabia (41); Tolosita (2). _Veracruz_: Jesús Carranza; 20 km. ENE of Jesús Carranza. The specimens listed above vary widely in color patterns; some of the patterns are characteristic of certain named "species": _albolabris_, _imitator_, _lineatissimus_, and _minimus_. The large series from the Río Sarabia contains all of the color patterns; this series was obtained in one small ravine in the rainforest. At least in the isthmian region, this species does not inhabit the Pacific slopes and lowlands. =Syrrhophus leprus= Cope _Oaxaca_: 33 km. N of Matías Romero; Santa Efigenia. _Veracruz_: San Lorenzo. Although the type locality is stated to be Santa Efigenia on the Pacific slopes of the Sierra Madre de Chiapas in eastern Oaxaca, the type specimen probably came from the northern slopes of the mountains. All other known specimens are from the Gulf slopes and lowlands, and from several localities in Los Tuxtlas. Details concerning specimens from the isthmus and other parts of the range were given by Duellman (1958c:8). Smith (1947:408) reported a specimen of _Syrrhophus verruculatus_ Peters from San Lorenzo, Veracruz; he stated that this specimen (USNM 123530) could not be _S. leprus_, because it had a gray belly, nor _S. cystignathoides_, because of the dark and light dorsal coloration. Firschein (1954:57) in his review of the species of _Syrrhophus_ in eastern México referred the specimen to _S. cystignathoides_. The specimen is in poor condition. Nevertheless, specific determination is possible. Numerous specimens of _S. leprus_ from Los Tuxtlas have gray bellies; some have heavier pigmentation than the specimen from San Lorenzo. In preservative the dorsum is dark brown with lighter mottling. There is little doubt that the specimen from San Lorenzo is a _Syrrhophus leprus_, an abundant and widespread species in the humid Gulf lowlands of southern México, and not _verruculatus_, if this is a valid species (see Firschein, _op. cit._:58), and not _cystignathoides_, a species known from San Luis Potosí southward to central Veracruz. =Syrrhophus pipilans pipilans= Taylor _Oaxaca_: Cerro Arenal; Cerro San Pedro; 6 km. N of Chivela; 14 km. W of Tehuantepec (2). In the isthmian region this frog is known only from the Pacific slopes and the Plains of Tehuantepec. Males call from the ground and from trees to heights of about four meters. The call is a single, high, long "peep." =Engystomops pustulosus= Cope _Oaxaca_: Chivela; La Ventosa (3); Santo Domingo; Tapanatepec (14); Tehuantepec (61); Unión Hidalgo (62). _Veracruz_: Acayucan; Cuatotolapam (7); 10 km. SE of Hueyapan (11). Large congregations were breeding at Tehuantepec on July 5, at Tapanatepec on July 13, and at Hueyapan on July 24, 1956. The frogs were breeding in open ponds in scrub forest and savanna; none was found in the rainforest. Males call while floating on the water (Pl. 7, fig. 1); the call is a soft "do-ing, do-ing" with a rising tone on the last note. Numerous individual egg masses were along the bank of a pond near Tehuantepec; one large composite egg mass there had a surface area of about one square meter (Pl. 7, fig. 2). The large series from Unión Hidalgo was obtained by digging specimens out of a dry sandy river bank in the dry season. Some of the individuals were buried to a depth of 25 centimeters. In life individuals from the Pacific lowlands were dull brown and gray; those from Acayucan were dark chocolate brown to black with pink or red blotches, forearms, and dorsal stripe. Not all specimens from the Atlantic lowlands are so colored; individuals from Cordoba and Mirador, Veracruz, are like those from Tehuantepec. =Leptodactylus labialis= Cope _Oaxaca_: Agua Caliente; Chivela (2); Matías Romero (12); 33 km. N of Matías Romero (4); Mixtequilla; Santa Efigenia; Tapanatepec; Tehuantepec (38); Tolosita (2); 33 km. W of Zanatepec (49). _Veracruz_: Acayucan (3); Ciudad Alemán; Cuatotolapam (10); Hueyapan; La Oaxaqueña (4); 38 km. SE of Jesús Carranza; 20 km. ENE of Jesús Carranza; Novillero (3); San Lorenzo (2). Although _Leptodactylus labialis_ does not appear to be so abundant as _Leptodactylus melanonotus_, the former was found throughout the lowlands of the isthmus. In the dry season individuals were found along streams, and in the rainy season breeding congregations were found in rain pools, marshes, ponds, and even small puddles. The call is a slow "wort, wort, wort." Males call beneath the water and from beneath rocks and from holes in the ground. The average snout-vent length of eight adult males is 37.2 mm. A completely metamorphosed juvenile obtained at Hueyapan on July 24, 1956, has a snout-vent length of 11 mm. =Leptodactylus melanonotus= Hallowell _Oaxaca_: Agua Caliente (25); Cerro Arenal (2); Cerro Quiengola (3); Cerro San Pedro (3); Chivela (2); Coyol; Juchitán; Matías Romero (11); Mixtequilla (2); Papaloapan (2); Salazar (9); Salina Cruz; 11 km. S of Santiago Chivela; Tapanatepec (17); Tehuantepec (176); Tolosita; Unión Hidalgo; 27 km. W of Zanatepec (6). _Veracruz_: Acayucan; Cuatotolapam (9); Cosoleacaque; 20 km. ENE of Jesús Carranza (2); 20 km. SE of Minatitlán (2); Novillero; San Lorenzo (6). This frog is abundant throughout the lowlands of the isthmus, where in the dry season individuals were found along streams and beneath rocks at a spring seepage. In the rainy season males were calling from nearly every bit of standing water. The call is a soft clicking sound resembling that made by striking two small stones together. The average snout-vent length of ten adult males is 41.8 mm. There is considerable variation in the extent of the yellowish brown glandular areas on the belly. Some have none, whereas others have a broad area on the chest, a band along the flanks, and a thin band across the lower abdomen. Individuals collected in the dry season vary in the same fashion as do those collected in the rainy season, at which time they were breeding. The glands are equally well-developed in adults of both sexes, and were present in some juveniles with snout-vent lengths of less than 20 mm. Apparently the development of the glands is not associated with maturity, sex, or size. =Diaglena reticulata= Taylor _Oaxaca_: Cerro Arenal; Chivela; Salina Cruz (26); San Antonio (3); Tehuantepec (2); 8.6 km. W of Tehuantepec (11); Zarzamora. Breeding congregations of this rare frog were found 8.6 kilometers west of Tehuantepec on July 5, 1956, and at Salina Cruz on July 6, 1958. Both choruses took place immediately after torrential rains. In both instances the frogs were in and about open muddy pools in the scrub forest (Pl. 5, fig. 2); males called from the bank near the water, and clasping pairs were found only on land (Pl. 8, figs. 1-2). The call is a loud, nasal "braaa," two to three seconds in duration. Amplexus is axillary. The dorsal ground color is light yellowish green tending towards olive on the head and fading to yellow on the flanks. The ventral surfaces, including the vocal sac, are white; the iris is golden and flecked with black. The present series agrees well with the description of _reticulata_ (based on two specimens) given by Taylor (1942:60). A detailed analysis of variation, comparison with related species, and descriptions of tadpoles are reserved for a future report. =Hyla baudini= Duméril and Bibron _Oaxaca_: Bisilana; Cerro Quiengola (2); Cerro San Pedro; Coyol; Matías Romero (12); Mixtequilla; Río Sarabia (7); Salazar; San Antonio; 11 km. S of Santiago Chivela; Santo Domingo (3); Tapanatepec (2); Tehuantepec (23); Tolosita. _Veracruz_: Acayucan; Amatitlán; Ciudad Alemán (3); Cosamaloapan (2); Cuatotolapam (15); 10 km. SE of Hueyapan; 20 km. S of Jesús Carranza; 38 km. S of Jesús Carranza (2); 20 km. ENE of Jesús Carranza (4); La Oaxaqueña (2); Minatitlán (2); Naranja (3); Novillero (9); Río de las Playas (2); San Lorenzo (5); Tapalapan (2). Commonly found on both sides of the isthmus, this large tree frog nearly always is associated with trees; it is not found in the savannas, although it breeds in savannas adjacent to rainforest. It appears to be somewhat more abundant in scrub forest than in rainforest. In the daytime individuals were found under the outer sheaths of banana plants, in the axils of leaves of elephant ears (_Xanthosoma_), in cavities in trees, and on shaded limbs in the forest. Recently metamorphosed individuals having snout-vent lengths slightly more than 20 mm. were found in the latter part of July. =Hyla ebraccata= Cope _Oaxaca_: Donají (17); 43 km. N of Matías Romero (27); Sarabia (6); Tolosita (3); Ubero (17). _Veracruz_: Aquilera. This small species was found only in forested areas, where calling males were on bushes and trees around rain pools. The call is a harsh squawk repeated at intervals of 15 to 20 seconds, followed by a minute or more of silence, and then repeated. Clasping pairs were found on bushes and in the water. The dorsum bears a dark chocolate brown hour glass-shaped mark, which in some individuals is broken into a large mark posteriorly and a smaller triangular one on the head and nape. The dorsal ground color varies from pale cream or ivory to yellow or tan. The intensity of the dorsal pigmentation is subject to rather rapid change. The flanks, hands, and anterior part of the venter are lemon yellow; the feet, thighs, and posterior part of the venter are golden yellow. The dorsal surface of the shank is yellow to tan with chocolate brown bars or spots; the heel is pale yellow. There is a dark brown bar in the loreal region and a dark brown bar extending posteriorly from the eye to a point above the insertion of the forelimb. The iris is a copper color. The toes are completely webbed; the fingers, one-third webbed. There is a small axillary web that is evident when the forelimbs are at right angles to the body. Twenty males have an average snout-vent length of 28.1 mm.; three females, 35.3 mm. There are no nuptial tuberosities on the pollex of breeding males. This species has been collected at Coyame and Catemaco in Los Tuxtlas and at various localities in Tabasco; it apparently ranges eastward from southern Veracruz, México, in humid forests to El Petén, Guatemala. =Hyla loquax= Gaige and Stuart _Oaxaca_: Donají (7); 43 km. N of Matías Romero (21). _Veracruz_: 19 km. N of Acayucan (4); Aquilera (3); 8 km. SW of Coatzacoalcos (36); Cuototolapam (11); Naranja (13); San Lorenzo (8). In the isthmus this species is known only from the humid forests of the Gulf lowlands; it is also known from Boca del Río, Veracruz, and from Teapa and Villa Hermosa, Tabasco. Calling males were found on aquatic plants above the water in deep ponds in the forest where it was necessary for the collector to wade waist-deep in water to obtain them. The call is a loud "hah-onk." Individuals, when active at night, are yellowish tan above with light olive green spots. The flanks, belly, and vocal sac are yellow, and the anterior and posterior surfaces of the thighs and webbing of the feet are bright orange-red or tomato red. Individuals found during the day are grayish brown with olive markings or reddish brown with black markings. Sleeping individuals are ivory-gray with faint gray markings. The iris is a bright copper color. Fifteen adult males have an average snout-vent length of 41.7 mm.; they have no horny nuptial pads on the pollex. The relationships of this species are with _Hyla rickardsi_ Taylor, a species known only from the foothills of the Sierra Madre Oriental in the states of Puebla and Veracruz. The distinguishing characteristics of these species are given in Table 1. Living individuals may be distinguished immediately by the flash colors on the thighs--red in _loquax_ and yellow in _rickardsi_. The calls of the two species are distinctly different; that of _rickardsi_ is a high-pitched, loud rattle continued for several seconds, notably different from the goose-like honk of _loquax_. TABLE 1.--COMPARISON OF CERTAIN CHARACTERS IN HYLA LOQUAX AND HYLA RICKARDSI =================================+================+==================== CHARACTER | _loquax_ | _rickardsi_ ---------------------------------+----------------+-------------------- Toe webbing | Full | Three-fourths | | Finger webbing | Three-fourths | One-half | | Average snout-vent length (Male) | 41.7 mm. | 37.4 mm. | | Tympanum/eye (Male) | 63.2% | 55.8% | | Dorsal leg pattern | Barred | Unmarked | | Tarsal fold | Tubercular | Absent | | Tarsal stripe | Absent or | Broad, indistinct, | indistinct | or absent | | Dorsolateral stripe | Absent | Present | | Light line over anus | Broad | Narrow | | Flash colors | Red | Yellow | | Iris color | Copper | Bronze ---------------------------------+----------------+-------------------- The three specimens from San Lorenzo, Veracruz (USNM 123513-5), were identified as _Hyla rickardsi_ by Smith (1947:409). The flash colors have faded in preservative, and so are of no aid in identifying these specimens. Two are adult females with snout-vent lengths of 35 and 39 mm. In possessing a relatively large tympanum and barred thighs, and in lacking a dorsolateral stripe they are typical of _loquax_, but in the amount of webbing on the hands and feet, broad tarsal stripe, and narrow anal stripe they are like _rickardsi_. The third specimen, a juvenile, has a snout-vent length of 25 mm. In coloration it resembles the adults; it has more distinct bars on the limbs. On the basis of geography these specimens should be _loquax_, for the closest known record of _rickardsi_ is more than 200 kilometers to the northwest, whereas _loquax_ is known from several localities around San Lorenzo. Shannon and Werler (1955:383) described _Hyla axillamembrana_ from the lower southern slopes of Los Tuxtlas. The unique type is a small male (27 mm. snout-vent). I have examined the type and find no great differences between it and small specimens of _loquax_. It is not possible to determine the color of the thighs, nor was this information given in the description. _Hyla axillamembrana_ is here considered to be a synonym of _Hyla loquax_. =Hyla microcephala martini= Smith _Oaxaca_: Donají (15); 43 km. N of Matías Romero (19); Río Sarabia (2); Sarabia (11); Tolosita. _Veracruz_: Acayucan (17); Alvarado (41); Aquilera (21); 8 km. SW of Coatzacoalcos (10); Cosoleacaque (26); 10 km. SE of Hueyapan; Naranja (3); Novillero. This frog is abundant in the Gulf lowlands of the isthmus, where large breeding congregations were found in grassy ponds on the savannas and in openings in the forest. Most frequently males were calling from grasses and reeds in the ponds; many individuals were perched precariously on thin blades as high as one meter above the water. The call is a series of low squeaks. Individuals found at night were pale yellow above with light brown lines arranged in an irregular pattern on the back, but often forming a cross or an X-shaped mark in the scapular region. There is a brown stripe from the nostril to the eye and thence to the groin. Anteriorly this stripe is bordered above by a thin white or cream-colored line. Numerous small brown flecks are scattered on the back and dorsal surface of the shank. In most specimens there are thin transverse brown bars on the shank. The thighs and undersides of the limbs are golden yellow; the belly and vocal sac are lemon yellow. The iris is yellowish brown. During the day individuals assume a pale reddish tan ground color with darker brown markings. Twenty-five adult males from Alvarado have an average snout-vent length of 24.1 mm. =Hyla picta= Günther _Oaxaca_: Donají (8); Sarabia (11); Tolosita (15); Ubero (6). _Veracruz_: 19 km. N of Acayucan (4); Alvarado (5); Aquilera; 8 km. SW of Coatzacoalcos; 10 km. SE of Hueyapan (7); Lerdo de Tejada; Tula (3). Widespread in the forests, scrub, and savannas on the Gulf lowlands of the isthmus, these frogs were found breeding at numerous localities. Males call from grasses and bushes growing in and about ponds. The call is a high-pitched insect-like trill. At night these frogs are pale yellow above; they change to light grayish tan during the day. A dark stripe extends from the nostril to the eye and thence posteriorly to a point between the axilla and groin. Above this dark stripe is a broader white stripe. Scattered on the dorsum are brown flecks or spots; the shanks are marked with poorly-defined cross-bars. The thighs are deep yellow below and paler above with scattered dark flecks. The belly is white, and the vocal sac is yellow. The iris is golden. Twenty males have an average snout-vent length of 21.5 mm.; three females, 24.0 mm. =Hyla robertmertensi= Taylor _Oaxaca_: Tapanatepec (28); 7.5 km. NW of Tapanatepec (38); 7.2 km. WNW of Zanatepec (77). This species was found in the isthmian region only on the Pacific lowlands at the southern base of the western part of the Sierra Madre de Chiapas. On July 13, 1956, many large choruses were discovered. The calling males were on reeds and thorn scrub in and at the edge of temporary ponds; the call is a cricket-like "creak-creack," quickly followed by a series of notes "creak-eek-eek-eek-eek." At night the dorsal ground color is pale yellow; this changes to pinkish buff during the day. There is a grayish or brown dark stripe from the nostril to the eye; the stripe continues to the groin. This dark stripe is bordered above by a narrow white stripe. The belly is white, and the vocal sac is yellow. The iris is dull reddish brown. Twenty-five males have an average snout-vent length of 24.7 mm. =Hyla staufferi= Cope _Oaxaca_: Chivela; Huilotepec (5); Juchitán (4); Matías Romero (4); 25 km. N of Matías Romero; Mixtequilla (4); Río Sarabia (11); 11 km. S of Santiago Chivela; Sarabia (3); Tapanatepec (67); Tehuantepec (66); Tolosita (2); Ubero; Unión Hidalgo; Zanatepec (6). _Veracruz_: Acayucan (7); Alvarado (3); Amatitlán; Aquilera; Ciudad Alemán (3); 8 km. SW of Coatzacoalcos (9); Cosamaloapan (4); Cosoleacaque (8); 10 km. SE of Hueyapan; Lerdo de Tejada; Novillero (6); Tula (2). This is the only species of small hylid that crosses the isthmus. Calling males were found in and about ponds on the savannas in southern Veracruz, in ponds in open forest in northern Oaxaca (not in forest pools), and in temporary pools in the scrub forest on the Pacific lowlands. Individuals usually called from bushes and reeds in or at the edge of ponds. The call is a short "braaa." Dates of breeding choruses indicate that by the time the other small species of hylids in the Gulf lowlands reach the peak of their breeding season, that of _H. staufferi_ is essentially over; no large breeding congregations were found in July. On July 8, 1956, two metamorphosing young were found clinging to blades of grass in a pond; they had snout-vent lengths of 8 and 9 mm. and tail stumps less than 3 mm. in length. Others were found on July 13 and 26. The juveniles are nearly unicolor olive green above and white below. In life the adults vary greatly in color pattern. The dorsal ground color is yellowish tan to olive brown with olive brown or dark brown spots, some of which in certain individuals are connected to form longitudinal dark stripes. On the posterior surface of the thighs are small white flecks. The belly is white, and the vocal sac is a rich yellow. Twenty males have an average snout-vent length of 26.3 mm.; they have no horny nuptial pads. No noticeable differences in either color or body proportions were found between the populations on either side of the isthmus. =Hylella sumichrasti= Brocchi _Oaxaca_: Cerro Arenal (5); Cerro San Pedro (2); Escurano; La Concepción (41); Portillo Los Nanches (6); San Antonio (16); 11 km. S of Santiago Chivela (18); Santa Lucía (7); Tapanatepec (5); Tehuantepec (8); Tenango (49); Tres Cruces (19). With the exception of the series from 11 kilometers south of Santiago Chivela, most of these specimens were found in small arboreal bromeliads during the dry season. Males were found along a clear, shallow, rocky stream south of Santiago Chivela on July 6, 1956. The frogs were calling from bushes and rocks in and along the stream. When disturbed, they jumped into the water and floated downstream until they were able to hold onto a rock or other object. The call is a loud "bra-a-ah." In breeding individuals the dorsum is pale yellow; the belly is white, and the vocal sac is yellow. The iris is pale golden yellow. Eighteen males have an average snout-vent length of 25.2 mm. All have dark brown nuptial tuberosities on the pollex. Certain diagnostic characters of this species as given by Taylor (1943a:50) and Taylor and Smith (1945:598) are in need of revision. _Hylella sumichrasti_ has been characterized as having no vocal sac, rarely having vomerine teeth, and as having a relatively smooth throat. The vocal sac in breeding males is quite evident; it is single, median, and when expanded, spherical. The openings into the vocal sac are narrow slits along the inner posterior border of the jaw rami. Of 151 specimens studied, 74 have vomerine ridges between the choanae, and 36 of these have one to three teeth on each ridge. The belly and undersurfaces of the thighs are granular; the throat is only somewhat less so. The granular condition may be correlated with breeding, for specimens obtained from bromeliads in the dry season had rather smooth throats. It seems that the vocal sac atrophys in the non-breeding season. These seasonal changes may account for the diagnoses given by Taylor (_op. cit._) and Taylor and Smith (_op. cit._); likewise, since many of the specimens obtained by Smith in the dry season were juveniles and subadults, the development of the vomerine ridges could not be diagnosed properly. The range of this species encompasses the Pacific slopes of the Isthmus of Tehuantepec eastward to the upper Cintalapa Valley and vicinity of Tonalá in western Chiapas. Priscilla Starrett collected tadpoles of _H. sumichrasti_ from a stream 19 km. N of Arriaga, Chiapas. These limited observations on the ecology of this frog suggest that it breeds in the fast-moving streams of the Pacific slopes, and that it seeks shelter in arboreal bromeliads during the dry season. =Phrynohyas modesta= Taylor and Smith _Oaxaca_: Tuxtepec. _Veracruz_: 20 km. S of Jesús Carranza; 20 km. ENE of Jesús Carranza (2); Minatitlán. I have not collected this species in the isthmus. The locality records indicate that the range is discontinuous (Duellman, 1956:27). The species occurs on the humid Pacific slopes from south-central Chiapas eastward to El Salvador and on the humid Gulf lowlands from southern Veracruz eastward into Tabasco, but is unknown from the dry Pacific slopes and plains in the isthmus. The acquisition of several specimens of this species in southern Veracruz, Tabasco, and Oaxaca, together with a knowledge of the variation displayed by _Phrynohyas spilomma_, suggests that _modesta_ may be a color variety of _spilomma_. =Phrynohyas spilomma= Cope _Oaxaca_: Tapanatepec (3). _Veracruz_: Amatitlán (12); Chacaltianguis (2); Ciudad Alemán (6); Cosamaloapan; Novillero (3). Like the preceding species, this frog is unknown from the arid Pacific lowlands of the isthmus; its presence at Tapanatepec, a locality situated in more mesic conditions than prevail on the Plains of Tehuantepec, indicates that it may have a distribution on the Pacific slopes much like that of _P. modesta_. Furthermore, this frog was not detected in the rainforests of the Gulf lowlands; in that region it was found only in scrub forest and savanna. On July 26, 1956, numerous choruses of these frogs were heard between Ciudad Alemán and Tlacotalpan, Veracruz. The call is a loud, nasal "grawl" repeated continuously. The males call from the water. Several clasping pairs were found in shallow grassy ponds amidst the scrub forest. The ground color varies from reddish brown to tan with dark brown dorsal markings. The iris is golden, and the vocal sacs are dark olive brown. After a light shower during the dry season, six individuals were found on the low branches of trees at night near Ciudad Alemán. =Phyllomedusa callidryas taylori= Funkhouser _Oaxaca_: Donají (9); Sarabia (8); Tolosita (6); Ubero (27). _Veracruz_: Alvarado (7); Aquilera; Berta; Coatzacoalcos (9); 10 km. SE of Hueyapan (5); Naranja (17). In life this frog presents a striking array of colors. The dorsum varies from pale green to dark olive green; there may be scattered whitish or cream-colored spots on the back. On the flanks are bright yellow to deep cream-colored vertical bars separated by pale blue or purple interspaces. The thighs and undersurfaces of the hind limbs are golden orange; the belly is yellow, and the throat is cream-colored. The iris is crimson; the transparent part of the lower eyelid has golden reticulations. When the frog is resting, the forefeet are folded beneath the throat, and the limbs are folded tightly against the body. In this position and with the eyes closed and head flattened, this gaudy frog assumes the appearance of a small elliptical green leaf. Throughout the month of July, 1956, _Phyllomedusa_ was breeding in ponds in or adjacent to the rainforest in northern Oaxaca and in southern Veracruz. Only at Alvarado was it found breeding in a grassy pond. Males and females alike were found on bushes and trees in and around the ponds. The call is a single "wank." Amplexing males continue to call, but the call is softer and less nasal in quality. The eggs are encased in pale green gelatin and attached to leaves on branches overhanging the water. Three egg clutches contained 38, 41, and 46 eggs. =Phyllomedusa dacnicolor= Cope _Oaxaca_: Escurano; Tehuantepec. Although it is abundant on the Pacific lowlands to the northwest in Guerrero, Michoacán, and Colima, this species is known only from two specimens from Tehuantepec. There is no apparent physical barrier to their distribution in the isthmus; in the Balsas Basin the species lives in a hotter, more arid environment than that at Tehuantepec. =Gastrophryne usta= Cope _Oaxaca_: Santa Efigenia; Tehuantepec (10); 24 km. W of Tehuantepec; Tolosita (2). _Veracruz_: Ayentes (6); La Oaxaqueña; Novillero (2); San Lorenzo. Calling males were found in open scrub forest near Tehuantepec and in savannas near Novillero. The specimens from Tolosita were found under cover in a clearing in the forest (Fugler and Webb, 1957:106). Specimens from the Pacific lowlands are typical of _Gastrophryne usta gadowi_ Boulenger in possessing a thin line on the posterior surface of the thighs and a thin line from the snout to the vent. Of nine specimens from the Gulf lowlands (Ayentes, Novillero, and San Lorenzo), seven have a middorsal line; this is narrow in four and wide in three. Five have the stripes on the thighs. Two specimens from the middle of the isthmus (Tolosita) have no stripes on the thighs; one has a thin middorsal line, and the other has a broad line. The adult males have a black throat; females have a mottled one. The brown reticulations on the bellies of specimens from the Gulf lowlands is bolder than on specimens from the Pacific lowlands. The presence of certain characters supposedly diagnostic of the subspecies _gadowi_ (line on dorsum and thighs) in the population of _usta_ in southern Veracruz suggests that a redefinition of the ranges of these subspecies will be in order when sufficient material is available to delimit them accurately. For the present I prefer to consider all specimens from the isthmus solely as _Gastrophryne usta_ without referring them to subspecies. =Rana palmipes= Spix _Oaxaca_: Matías Romero (11); 11 km. S of Santiago Chivela; Santo Domingo; Sarabia. _Veracruz_: Coatzacoalcos; Cuatotolapam; 25 km. SE of Jesús Carranza (4); Tlacotalpan (2); Tula. Adults were found along streams and in marshes in savannas and rainforest. These frogs are wary and difficult to capture, even at night. _Rana palmipes_ is another species that has a discontinuous distribution in the isthmus. The species does not occur on the Pacific lowlands of the isthmus, but does occur on the more humid Pacific slopes of Chiapas and Guatemala. Tadpoles were found in a small sluggish tributary to the Río Sarabia. =Rana pipiens= Schreber _Oaxaca_: Agua Caliente; Cerro Quiengola; Escurano (14); Río Sarabia (2); Tapanatepec (5); Tehuantepec (24). _Veracruz_: Acayucan; Cuatotolapam (15); Jesús Carranza (2); 20 km. S of Jesús Carranza (11); 25 km. SE of Jesús Carranza; 20 km. ENE of Jesús Carranza (10); San Lorenzo (10). As in most other places in México and northern Central America, this species occurs wherever there is permanent water. Males were heard calling from woodland ponds and from savanna ponds. SUMMARY Investigations of the amphibians and their environments in the Isthmus of Tehuantepec have been presented with the aim of gaining an understanding of the present biological and of the historical events responsible for the present patterns of distribution of amphibians in this region. The Isthmus of Tehuantepec embraces three major environments--savanna, semi-arid scrub forest, and quasi-rainforest. The rainforest presents an environment noticeably different from the other two and has a different amphibian fauna. Analysis of present patterns of distribution shows that certain species are restricted to the rainforests on the Gulf lowlands; others live only in the semi-arid scrub forests on the Pacific lowlands. A third group of species lives on both the Gulf and Pacific lowlands; most of these species occur only in the scrub forests or savannas on the Gulf lowlands, but some also inhabit the rainforest. In one way or another the isthmus presents a barrier to the distribution of 75 per cent of the species of amphibians living in the lowlands; it is a greater barrier still to the species inhabiting the highlands on either side. Present patterns of distribution are attributed to bioclimatic fluctuation in the Pleistocene. In the course of these climatic shifts, tropical environments and their amphibian inhabitants seem to have survived in the isthmian region. The amphibian fauna of the lowlands of the Isthmus of Tehuantepec consists of 16 genera and 36 species. Systematic studies of all available specimens from the region show that _Eleutherodactylus conspicuus_ Taylor and Smith is a synonym of _Eleutherodactylus alfredi_ Boulenger and that _Hyla axillamembrana_ Shannon and Werler is a synonym of _Hyla loquax_ Gaige and Stuart. LITERATURE CITED BEARD, J. S. 1953. The savanna vegetation of northern tropical America. Ecol. Mono., vol. 23 (2):149-215. BOULENGER, G. A. 1898. Fourth report on additions to the batrachian collection in the Natural History Museum. Proc. Zool. Soc. London, 1898, pp. 473-482, pls. 38-39. BURT, C. E. 1931. A study of the teiid lizards of the genus _Cnemidophorus_ with special reference to their phylogenetic relationships. Bull. U. S. Nat. Mus., No. 154, pp. viii + 286. CONTRERAS A., A. 1942. Mapa de las provincias climatologias de la Republica Mexicana. México, D. F., Dirección de Geografía, Meterología e Hidrología, pp. i-xxviii, tables 1-54, 2 maps. COOKE, C. W. 1945. Geology of Florida. Florida Geol. Surv., Geol. Bull., No. 29:1-339. DORF, E. 1959. Climatic changes of the past and present. Contrib. Mus. Paleo. Univ. Michigan, vol. 13 (8):181-210. DUELLMAN, W. E. 1956. The frogs of the hylid genus _Phrynohyas_ Fitzinger, 1843. Miscl. Publ. Mus. Zool. Univ. Michigan, No. 96:1-47, pls. 1-6. 1958a. A monographic study of the colubrid snake genus _Leptodeira_. Bull. Amer. Mus. Nat. Hist., vol. 114:1-152, pls. 1-31. 1958b. A preliminary analysis of the herpetofauna of Colima, Mexico. Occas. Papers Mus. Zool. Univ. Michigan, No. 589:1-22. 1958c. A review of the frogs of the genus _Syrrhophus_ in western Mexico. Occas. Papers Mus. Zool. Univ. Michigan, No. 594:1-15, pls. 1-3. DUELLMAN, W. E., and SCHWARTZ, A. 1958. Amphibians and reptiles of southern Florida. Bull. Florida State Mus., vol. 3 (5):181-324. DUNN, E. R. 1942. The American caecilians. Bull. Mus. Comp. Zool., vol. 91 (6):439-540. DURHAM, J. W., ARELLANO, A. R. V., and PECK, JR., J. H. 1952. No Cenozoic Tehuantepec seaways. Bull. Geol. Soc. Amer., vol. 63:1245. FIRSCHEIN, I. L. 1950. A new toad from Mexico with a redefinition of the _cristatus_ group. Copeia, 1950 (2):81-87, pl. 1. 1954. Definition of some little-understood members of the leptodactylid genus _Syrrhophus_, with a description of a new species. Copeia, 1954 (1):48-58. FIRSCHEIN, I. L., and SMITH, H. M. 1957. A high-crested race of toad (_Bufo valliceps_) and other noteworthy reptiles and amphibians from southern Mexico. Herpetologica, vol. 13 (3):219-222. FUGLER, C. M., and WEBB, R. G. 1957. Some noteworthy reptiles and amphibians from the states of Oaxaca and Veracruz. Herpetologica, vol. 13 (2):103-108. GLOYD, H. K. 1940. The rattlesnakes, genera _Sistrurus_ and _Crotalus_. Chicago Acad. Sci. Special Publ., No. 4, vii + 266 pp., pls. 1-31. GOIN, C. J. 1958. Comments upon the origin of the herpetofauna of Florida. Quart. Jour. Florida Acad. Sci., vol. 21 (1):61-70. GOLDMAN, E. A. 1951. Biological investigations in Mexico. Smithsonian Misc. Publ., vol. 115, xiii + 476 pp., pls. 1-71. GOODNIGHT, C. J., and GOODNIGHT, M. L. 1956. Some observations in a tropical rain forest in Chiapas, Mexico. Ecology, vol. 37 (1):139-150. GRISCOM, L. 1932. The distribution of bird-life in Guatemala. Bull. Amer. Mus. Nat. Hist., vol. 64:1-439. 1950. Distribution and origin of the birds of Mexico. Bull. Mus. Comp. Zool., vol. 103:341-382. HARTWEG, N., and OLIVER, J. A. 1940. A contribution to the herpetology of the Isthmus of Tehuantepec. IV. An annotated list of the amphibians and reptiles collected on the Pacific slope during the summer of 1936. Misc. Publ. Mus. Zool. Univ. Michigan, No. 47:1-31. HUBBELL, T. H. 1954. Relationships and distribution of _Mycotrupes_. In The burrowing beetles of the genus _Mycotrupes_, Olson, A. L., Hubbell, T. H., and Howden, H. F. Misc. Publ. Mus. Zool. Univ. Michigan, No. 84:1-59, pls. 1-8. HUTCHINSON, G. E., PATRICK, R., and DEEVEY, E. S. 1956. Sediments of Lake Patzcuaro, Michoacán, Mexico. Bull. Geol. Soc. Amer., vol. 67:1491-1504. LANGEBARTEL, D. A., and SMITH, P. W. 1959. Noteworthy records of amphibians and reptiles from eastern Mexico. Herpetologica, vol. 15 (1):27-29. MARTIN, P. S. 1958. Pleistocene ecology and biogeography of North America. Zoogeography. Amer. Assoc. Advanc. Sci., Publ. No. 51:375-420. MARTIN, P. S., and HARRELL, B. E. 1957. The Pleistocene history of temperate biotas in Mexico and eastern United States. Ecology, vol. 38:468-480. OLIVER, J. A. 1948. The relationships and zoogeography of the genus _Thalerophis_ Oliver. Bull. Amer. Mus. Nat. Hist., vol. 92:157-280, pls. 16-19. OLSON, E. C., and MCGREW, P. O. 1941. Mammalian fauna from the Pliocene of Honduras. Bull. Geol. Soc. Amer., vol. 52:1219-1244. RUTHVEN, A. G. 1912. The amphibians and reptiles collected by the University of Michigan--Walker Expedition in southern Vera Cruz, Mexico. Zool. Jahrbuch, vol. 32 (4):295-332, pls. 6-11. SCHUCHERT, C. 1935. Historical geology of the Antillean-Caribbean region. New York, xxvi + 811 pp. SEARS, P. B., FOREMAN, F., and CLISBY, K. H. 1955. Palynology in southern North America. Bull. Geol. Soc. Amer., vol. 66:471-530. SHANNON, F. A., and WERLER, J. 1955. Notes on amphibians of the Los Tuxtlas Range of Veracruz, Mexico. Trans. Kansas Acad. Sci., vol. 58 (3):360-386. SHREVE, B. 1957. Reptiles and amphibians from the Selva Lacandona. _In_ Biological Investigations in the Selva Lacandona, Chiapas, Mexico. Paynter, R. A. (editor). Bull. Mus. Comp. Zool., vol. 116 (4):193-298. SMITH, H. M. 1947. Notes on Mexican amphibians and reptiles. Jour. Washington Acad. Sci., vol. 37:408-412. SMITH, H. M., and LAUFE, L. E. 1946. A summary of Mexican Lizards of the genus _Ameiva_. Univ. Kansas Sci. Bull., vol. 31 (2):7-73. SMITH, H. M., and TAYLOR, E. H. 1950. An annotated checklist and key to the reptiles of Mexico exclusive of the snakes. Bull. U. S. Natl. Mus., No. 199, v + 253 pp. STIRTON, R. A. 1954. Late Miocene mammals from Oaxaca, Mexico. Amer. Jour. Sci., No. 252:634-638. STUART, L. C. 1935. A contribution to a knowledge of the herpetology of a portion of the savanna region of central Petén, Guatemala. Misc. Publ. Mus. Zool. Univ. Michigan, No. 29:1-56, pls. 1-4. 1941. Studies of Neotropical Colubridae VIII. A revision of the genus _Dryadophis_ Stuart, 1939. Misc. Publ. Mus. Zool. Univ. Michigan, No. 49:1-106, pls. 1-4. 1951. The herpetofauna of the Guatemalan Plateau, with special reference to its distribution on the southwestern highlands. Contrib. Lab. Vertebrate Biol., Univ. Michigan, No. 49:1-71, pls. 1-7. 1954. A description of a subhumid corridor across northern Central America, with comments on its herpetofaunal indicators. Contrib. Lab. Vertebrate Biol., Univ. Michigan, No. 65:1-26, pls. 1-6. 1958. A study of the herpetofauna of the Uaxactun-Tikal area of northern El Petén, Guatemala. Contrib. Lab. Vertebrate Biol., Univ. Michigan, No. 75:1-30. TAYLOR, E. H. 1940. New species of Mexican Anura. Univ. Kansas Sci. Bull., vol. 26 (11):385-405. 1941. New amphibians from the Hobart M. Smith Mexican collections. Univ. Kansas Sci. Bull., vol. 27 (8):141-167. 1942. The frog genus _Diaglena_ with a description of a new species. Univ. Kansas Sci. Bull., vol. 28 (4):57-65. 1943a. A new _Hylella_ from Mexico. Proc. Biol. Soc. Washington, vol. 56:49-52. 1943b. Herpetological novelties from Mexico. Univ. Kansas Sci. Bull., vol. 29 (8):343-361. TAYLOR, E. H., and SMITH, H. M. 1945. Summary of the collections of amphibians made in Mexico under the Walter Rathbone Bacon Traveling Scholarship. Proc. U. S. Natl. Mus., vol. 95:521-613, pls. 18-32. TRASK, P. D., PHLEGER, F. B., and STETSON, H. C. 1947. Recent changes in sedimentation in the Gulf of Mexico. Science, vol. 106:460-461. WEYL, R. 1955. Vestigios de una glaciacion del Pleistoceno en la Cordillera de Talamanca, Costa Rica, A. C. Informe Trimestral, Inst. Geog. de Costa Rica, pp. 9-32. WHITE, S. E. 1956. Probable substages of glaciation on Ixtaccihuatl, Mexico. Jour. Geol., vol. 64:289-295. WILLIAMS, L. 1939. Arboles y arbustos del Istmos de Tehuantepec, Mexico. Lilloa., vol. 4:137-171. _Transmitted May 23, 1960._ UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Institutional libraries interested in publications exchange may obtain this series by addressing the Exchange Librarian, University of Kansas Library, Lawrence, Kansas. Copies for individuals, persons working in a particular field of study, may be obtained by addressing instead the Museum of Natural History, University of Kansas, Lawrence, Kansas. There is no provision for sale of this series by the University Library, which meets institutional requests, or by the Museum of Natural History, which meets the requests of individuals. However, when individuals request copies from the Museum, 25 cents should be included, for each separate number that is 100 pages or more in length, for the purpose of defraying the costs of wrapping and mailing. * An asterisk designates those numbers of which the Museum's supply (not the Library's supply) is exhausted. Numbers published to date, in this series, are as follows: Vol. 1. Nos. 1-26 and index. Pp. 1-638, 1946-1950. *Vol. 2. (Complete) Mammals of Washington. By Walter W. Dalquest. Pp. 1-444, 140 figures in text. April 9, 1948. Vol. 3. *1. The avifauna of Micronesia, its origin, evolution, and distribution. By Rollin H. Baker. Pp. 1-359, 16 figures in text. June 12, 1951. *2. A quantitative study of the nocturnal migration of birds. By George H. Lowery, Jr. Pp. 361-472, 47 figures in text. June 29, 1951. 3. Phylogeny of the waxwings and allied birds. By M. Dale Arvey. Pp. 473-530, 49 figures in text, 13 tables. October 10, 1951. 4. Birds from the state of Veracruz, Mexico. By George H. Lowery, Jr., and Walter W. Dalquest. Pp. 531-649, 7 figures in text, 2 tables. October 10, 1951. Index. Pp. 651-681. *Vol. 4. (Complete) American weasels. By E. Raymond Hall. Pp. 1-466, 41 plates, 31 figures in text. December 27, 1951. Vol. 5. Nos. 1-37 and index. Pp. 1-676, 1951-1953. *Vol. 6. (Complete) Mammals of Utah, _taxonomy and distribution_. By Stephen D. Durrant. Pp. 1-549, 91 figures in text, 80 tables. August 10, 1952. Vol. 7. *1. Mammals of Kansas. By E. Lendell Cockrum. Pp. 1-303, 73 figures in text, 37 tables. August 25, 1952. 2. Ecology of the opossum on a natural area in northeastern Kansas. By Henry S. Fitch and Lewis L. Sandidge. Pp. 305-338, 5 figures in text. August 24, 1953. 3. The silky pocket mice (Perognathus flavus) of Mexico. By Rollin H. Baker. Pp. 339-347, 1 figure in text. February 15, 1954. 4. North American jumping mice (Genus Zapus). By Philip H. Krutzsch. Pp. 349-472, 47 figures in text, 4 tables. April 21, 1954. 5. Mammals from Southeastern Alaska. By Rollin H. Baker and James S. Findley. Pp. 473-477. April 21, 1954. 6. Distribution of Some Nebraskan Mammals. By J. Knox Jones, Jr. Pp. 479-487. April 21, 1954. 7. Subspeciation in the montane meadow mouse. Microtus montanus, in Wyoming and Colorado. By Sydney Anderson. Pp. 489-506, 2 figures in text. July 23, 1954. 8. A new subspecies of bat (Myotis velifer) from southeastern California and Arizona. By Terry A. Vaughan. Pp. 507-512. July 23, 1954. 9. Mammals of the San Gabriel mountains of California. By Terry A. Vaughan. Pp. 513-582, 1 figure in text, 12 tables. November 15, 1954. 10. A new bat (Genus Pipistrellus) from northeastern Mexico. By Rollin H. Baker. Pp. 583-586. November 15, 1954. 11. A new subspecies of pocket mouse from Kansas. By E. Raymond Hall. Pp. 587-590. November 15, 1954. 12. Geographic variation in the pocket gopher, Cratogeomys castanops, in Coahuila, Mexico. By Robert J. Russell and Rollin H. Baker. Pp. 591-608. March 15, 1955. 13. A new cottontail (Sylvilagus floridanus) from northeastern Mexico. By Rollin H. Baker. Pp. 609-612. April 8, 1955. 14. Taxonomy and distribution of some American shrews. By James S. Findley. Pp. 613-618. June 10, 1955. 15. The pigmy woodrat, Neotoma goldmani, its distribution and systematic position. By Dennis G. Rainey and Rollin H. Baker. Pp. 619-624. 2 figures in text. June 10, 1955. Index. Pp. 625-651. Vol. 8. 1. Life history and ecology of the five-lined skink, Eumeces fasciatus. By Henry S. Fitch. Pp. 1-156, 26 figures in text. September 1, 1954. 2. Myology and serology of the Avian Family Fringillidae, a taxonomic study. By William B. Stallcup. Pp. 157-211, 23 figures in text, 4 tables. November 15, 1954. 3. An ecological study of the collared lizard (Crotaphytus collaris). By Henry S. Fitch. Pp. 213-274, 10 figures in text. February 10, 1956. 4. A field study of the Kansas ant-eating frog, Gastrophryne olivacea. By Henry S. Fitch. Pp. 275-306, 9 figures in text. February 10, 1956. 5. Check-list of the birds of Kansas. By Harrison B. Tordoff. Pp. 307-359, 1 figure in text. March 10, 1956. 6. A population study of the prairie vole (Microtus ochrogaster) in northeastern Kansas. By Edwin P. Martin. Pp. 361-416, 19 figures in text. April 2, 1956. 7. Temperature responses in free-living amphibians and reptiles of northeastern Kansas. By Henry S. Fitch. Pp. 417-476, 10 figures in text, 6 tables. June 1, 1956. 8. Food of the crow, Corvus brachyrhynchos Brehm, in south-central Kansas. By Dwight Platt. Pp. 477-498, 4 tables. June 8, 1956. 9. Ecological observations on the woodrat, Neotoma floridana. By Henry S. Fitch and Dennis G. Rainey. Pp. 499-533, 3 figures in text. June 12, 1956. 10. Eastern woodrat, Neotoma floridana: Life history and ecology. By Dennis G. Rainey. Pp. 535-646, 12 plates, 13 figures in text. August 15, 1956. Index. Pp. 647-675. Vol. 9. 1. Speciation of the wandering shrew. By James S. Findley. Pp. 1-68, 18 figures in text. December 10, 1955. 2. Additional records and extensions of ranges of mammals from Utah. By Stephen D. Durrant, M. Raymond Lee, and Richard M. Hansen. Pp. 69-80. December 10, 1955. 3. A new long-eared myotis (Myotis evotis) from northeastern Mexico. By Rollin H. Baker and Howard J. Stains. Pp. 81-84. December 10, 1955. 4. Subspeciation in the meadow mouse, Microtus pennsylvanicus, in Wyoming. By Sydney Anderson. Pp. 85-104, 2 figures in text. May 10, 1956. 5. The condylarth genus Ellipsodon. By Robert W. Wilson. Pp. 105-116, 6 figures in text. May 19, 1956. 6. Additional remains of the multituberculate genus Eucosmodon. By Robert W. Wilson. Pp. 117-123, 10 figures in text. May 19, 1956. 7. Mammals of Coahuila, Mexico. By Rollin H. Baker. Pp. 125-335, 75 figures in text. June 15, 1956. 8. Comments on the taxonomic status of Apodemus peninsulae, with description of a new subspecies from North China. By J. Knox Jones, Jr. Pp. 337-346, 1 figure in text, 1 table. August 15, 1956. 9. Extensions of known ranges of Mexican bats. By Sydney Anderson. Pp. 347-351. August 15, 1956. 10. A new bat (Genus Leptonycteris) from Coahuila. By Howard J. Stains. Pp. 353-356. January 21, 1957. 11. A new species of pocket gopher (Genus Pappogeomys) from Jalisco, Mexico. By Robert J. Russell. Pp. 357-361. January 21, 1957. 12. Geographic variation in the pocket gopher, Thomomys bottae, in Colorado. By Phillip M. Youngman. Pp. 363-384, 7 figures in text. February 21, 1958. 13. New bog lemming (genus Synaptomys) from Nebraska. By J. Knox Jones, Jr. Pp. 385-388. May 12, 1958. 14. Pleistocene bats from San Josecito Cave, Nuevo León, México. By J. Knox Jones, Jr. Pp. 389-396. December 19, 1958. 15. New Subspecies of the rodent Baiomys from Central America. By Robert L. Packard. Pp. 397-404. December 19, 1958. 16. Mammals of the Grand Mesa, Colorado. By Sydney Anderson. Pp. 405-414, 1 figure in text. May 20, 1959. 17. Distribution, variation, and relationships of the montane vole, Microtus montanus. By Emil K. Urban. Pp. 415-511. 12 figures in text, 2 tables. August 1, 1959. 18. Conspecificity of two pocket mice, Perognathus goldmani and P. artus. By E. Raymond Hall and Marilyn Bailey Ogilvie. Pp. 513-518, 1 map. January 14, 1960. 19. Records of harvest mice, Reithrodontomys, from Central America, with description of a new subspecies from Nicaragua. By Sydney Anderson and J. Knox Jones, Jr. Pp. 519-529. January 14, 1960. 20. Small carnivores from San Josecito Cave (Pleistocene), Nuevo León, México. By E. Raymond Hall. Pp. 531-538, 1 figure in text. January 14, 1960. 21. Pleistocene pocket gophers from San Josecito Cave, Nuevo León, México. By Robert J. Russell. Pp. 539-548, 1 figure in text. January 14, 1960. 22. Review of the insectivores of Korea. By J. Knox Jones, Jr., and David H. Johnson. Pp. 549-578. February 23, 1960. 23. Speciation and evolution of the pygmy mice, genus Baiomys. By Robert L. Packard. Pp. 579-670, 4 plates, 12 figures in text. June 16, 1960. Index Pp. 671-690. Vol. 10. 1. Studies of birds killed in nocturnal migration. By Harrison B. Tordoff and Robert M. Mengel. Pp. 1-44, 6 figures in text, 2 tables. September 12, 1956. 2. Comparative breeding behavior of Ammospiza caudacuta and A. maritima. By Glen E. Woolfenden. Pp. 45-75, 6 plates, 1 figure. December 20, 1956. 3. The forest habitat of the University of Kansas Natural History Reservation. By Henry S. Fitch and Ronald R. McGregor. Pp. 77-127, 2 plates, 7 figures in text, 4 tables. December 31, 1956. 4. Aspects of reproduction and development in the prairie vole (Microtus ochrogaster). By Henry S. Fitch. Pp. 129-161, 8 figures in text, 4 tables. December 19, 1957. 5. Birds found on the Arctic slope of northern Alaska. By James W. Bee. Pp. 163-211, pls. 9-10, 1 figure in text. March 12, 1958. 6. The wood rats of Colorado: distribution and ecology. By Robert B. Finley, Jr. Pp. 213-552, 34 plates, 8 figures in text, 35 tables. November 7, 1958. 7. Home ranges and movements of the eastern cottontail in Kansas. By Donald W. Janes. Pp. 553-572, 4 plates, 3 figures in text. May 4, 1959. 8. Natural history of the salamander, Aneides hardyi. By Richard F. Johnston and Schad Gerhard. Pp. 573-585. October 8, 1959. 9. A new subspecies of lizard, Cnemidophorus sacki, from Michoacán, México. By William E. Duellman. Pp. 587-598, 2 figures in text. May 2, 1960. 10. A taxonomic study of the Middle American Snake, Pituophis deppei. By William E. Duellman. Pp. 599-610, 1 plate, 1 figure in text. May 2, 1960. Index Pp. 611-626. Vol. 11. 1. The systematic status of the colubrid snake, Leptodeira discolor Günther. By William E. Duellman. Pp. 1-9, 4 figs. July 14, 1958. 2. Natural history of the six-lined racerunner, Cnemidophorus sexlineatus. By Henry S. Fitch. Pp. 11-62, 9 figs., 9 tables. September 19, 1958. 3. Home ranges, territories, and seasonal movements of vertebrates of the Natural History Reservation. By Henry S. Fitch. Pp. 63-326, 6 plates, 24 figures in text, 3 tables. December 12, 1958. 4. A new snake of the genus Geophis from Chihuahua, Mexico. By John M. Legler. Pp. 327-334, 2 figures in text. January 28, 1959. 5. A new tortoise, genus Gopherus, from north-central Mexico. By John M. Legler. Pp. 335-343. April 24, 1959. 6. Fishes of Chautauqua, Cowley and Elk counties, Kansas. By Artie L. Metcalf. Pp. 345-400, 2 plates, 2 figures in text, 10 tables. May 6, 1959. 7. Fishes of the Big Blue River Basin, Kansas. By W. L. Minckley. Pp. 401-442, 2 plates, 4 figures in text, 5 tables. May 8, 1959. 8. Birds from Coahuila, México. By Emil K. Urban. Pp. 443-516. August 1, 1959. 9. Description of a new softshell turtle from the southeastern United States. By Robert G. Webb. Pp. 517-525, 2 pls., 1 figure in text, August 14, 1959. 10. Natural history of the ornate box turtle, Terrapene ornata ornata Agassiz. By John M. Legler. Pp. 527-669, 16 pls., 29 figures in text. March 7, 1960. Index will follow. Vol. 12. 1. Functional morphology of three bats: Eumops, Myotis, Macrotus. By Terry A. Vaughan. Pp. 1-153, 4 plates, 24 figures in text, July 8, 1959. 2. The ancestry of modern Amphibia: a review of the evidence. By Theodore H. Eaton, Jr. Pp. 155-180, 10 figures in text. July 10, 1959. 3. The baculum in microtine rodents. By Sydney Anderson. Pp. 181-216, 49 figures in text. February 19, 1960. 4. A new order of fishlike Amphibia from the Pennsylvanian of Kansas. By Theodore H. Eaton, Jr., and Peggy Lou Stewart. Pp. 217-240, 12 figures in text. May 2, 1960. More numbers will appear in volume 12. Vol. 13. 1. Five natural hybrid combinations in minnows (Cyprinidae). By Frank B. Cross and W. L. Minckley. Pp. 1-18. June 1, 1960. 2. A distributional study of the amphibians of the isthmus of Tehuantepec, México. By William E. Duellman. Pp. 19-72, pls. 1-8, 3 figs. August 16, 1960. More numbers will appear in volume 13. * * * * * Transcriber's Notes Page 26: Changed "19. Cosaleacaque" to "19. Cosoleacaque". Page 30: Changed "Brysonima crassifolia" to "Byrsonima crassifolia". Page 34: Changed "long. 95' 29°;" to "long. 95° 29';". Page 35: Changed "Matías Romera" to "Matías Romero". Page 47: Changed "kown" to "known". Pages 50 and 59: Changed "axills" to "axils". Plate 1, Fig. 2: Changed "Veracuz" to "Veracruz". Page 53: Changed "valadity" to "validity". Page 61, Table 1: Changed male symbol to "(Male)" (plain text version). Page 67: Changed "refering" to "referring". Page 68: Changed "survided" to "survived". Page 71: Changed "subhimid" to "subhumid" and "Amerca" to "America". Moved University of Kansas Publications list to end of report. Vol. 9, No. 12: Changed pages from "363-387" to "363-384". Vol. 10, No. 10: Changed pages from "599-612" to "599-610". 
37823	----	UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 17, No. 7, pp. 281-375, pls. 1-12, 17 figs. July 14, 1966 Neotropical Hylid Frogs, Genus Smilisca BY WILLIAM E. DUELLMAN AND LINDA TRUEB UNIVERSITY OF KANSAS LAWRENCE 1966 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Frank B. Cross Volume 17, No. 7, pp. 281-375, pls. 1-12, 17 figs. Published July 14, 1966 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY ROBERT R. (BOB) SANDERS, STATE PRINTER TOPEKA, KANSAS 1966 [Illustration: Look for the Union label.] 31-3430 Neotropical Hylid Frogs, Genus Smilisca BY WILLIAM E. DUELLMAN AND LINDA TRUEB CONTENTS PAGE INTRODUCTION 285 Acknowledgments 286 Materials and Methods 287 GENUS SMILISCA COPE, 1865 287 Key to Adults 288 Key to Tadpoles 289 ACCOUNTS OF SPECIES 289 _Smilisca baudini_ (Duméril and Bibron) 289 _Smilisca cyanosticta_ (Smith) 303 _Smilisca phaeota_ (Cope) 308 _Smilisca puma_ (Cope) 314 _Smilisca sila_ New species 318 _Smilisca sordida_ (Peters) 323 ANALYSIS OF MORPHOLOGICAL CHARACTERS 330 Osteology 330 _Descriptive Osteology of Smilisca baudini_ 331 _Developmental Cranial Osteology of Smilisca baudini_ 333 _Comparative Osteology_ 336 Musculature 341 Skin 342 _Structure_ 342 _Comparative Biochemistry of Proteins_ 343 External Morphological Characters 343 _Size and Proportions_ 343 _Shape of Snout_ 344 _Hands and Feet_ 344 _Ontogenetic Changes_ 344 Coloration 344 _Metachrosis_ 345 Chromosomes 345 NATURAL HISTORY 345 Breeding 345 _Time of Breeding_ 345 _Breeding Sites_ 346 _Breeding Behavior_ 346 _Breeding Call_ 351 Eggs 356 Tadpoles 357 _General Structure_ 357 _Comparison of Species_ 357 _Growth and Development_ 361 _Behavior_ 365 PHYLOGENETIC RELATIONSHIPS 366 Interspecific Relationships 366 Evolutionary History 369 SUMMARY AND CONCLUSIONS 371 LITERATURE CITED 372 INTRODUCTION The family Hylidae, as currently recognized, is composed of about 34 genera and more than 400 species. Most genera (30) and about 350 species live in the American tropics. _Hyla_ and 10 other genera inhabit Central America; four of those 10 genera (_Gastrotheca_, _Hemiphractus_, _Phrynohyas_, and _Phyllomedusa_) are widely distributed in South America. The other six genera are either restricted to Central America or have their greatest differentiation there. _Plectrohyla_ and _Ptychohyla_ inhabit streams in the highlands of southern Mexico and northern Central America; _Diaglena_ and _Triprion_ are casque-headed inhabitants of arid regions in México and northern Central America. _Anotheca_ is a tree-hole breeder in cloud forests in Middle America. The genus _Smilisca_ is the most widespread geographically and diverse ecologically of the Central American genera. The definition of genera in the family Hylidae is difficult owing to the vast array of species, most of which are poorly known as regards their osteology, colors in life, and modes of life history. The genera _Diaglena_, _Triprion_, _Tetraprion_, _Osteocephalus_, _Trachycephalus_, _Aparasphenodon_, _Corythomantis_, _Hemiphractus_, _Pternohyla_, and _Anotheca_ have been recognized as distinct from one another and from the genus _Hyla_ on the basis of various modifications of dermal bones of the cranium. _Phyllomedusa_ is recognized on the basis of a vertical pupil and opposable thumb; _Plectrohyla_ is characterized by the presence of a bony prepollex and the absence of a quadratojugal. _Gastrotheca_ is distinguished from other hylids by the presence of a pouch in the back of females. A pair of lateral vocal sacs behind the angles of the jaws and the well-developed dermal glands were used by Duellman (1956) to distinguish _Phrynohyas_ from _Hyla_. He (1963a) cited the ventrolateral glands in breeding males as diagnostic of _Ptychohyla_. Some species groups within the vaguely defined genus _Hyla_ have equally distinctive characters. The _Hyla septentrionalis_ group is characterized by a casque-head, not much different from that in the genus _Osteocephalus_ (Trueb, MS). Males in the _Hyla maxima_ group have a protruding bony prepollex like that characteristically found in _Plectrohyla_. Ontogenetic development, osteology, breeding call, behavior, and ecology are important in the recognition of species. By utilizing the combination of many morphological and biological factors, the genus _Smilisca_ can be defined reasonably well as a natural, phyletic assemblage of species. Because the wealth of data pertaining to the morphology and biology of _Smilisca_ is lacking for most other tree frogs in Middle America it is not possible at present to compare _Smilisca_ with related groups in more than a general way. _Smilisca_ is an excellent example of an Autochthonous Middle American genus. As defined by Stuart (1950) the Autochthonous Middle American fauna originated from "hanging relicts" left in Central America by the ancestral fauna that moved into South America and differentiated there at a time when South America was isolated from North and Middle America. The genus _Smilisca_, as we define it, consists of six species, all of which occur in Central America. One species ranges northward to southern Texas, and one extends southward on the Pacific lowlands of South America to Ecuador. We consider the genus _Smilisca_ to be composed of rather generalized hylids. Consequently, an understanding of the systematics and zoogeography of the genus can be expected to be of aid in studying more specialized members of the family. Acknowledgments Examination of many of the specimens used in our study was possible only because of the cooperation of the curators of many systematic collections. For lending specimens or providing working space in their respective institutions we are grateful to Doris M. Cochran, Alice G. C. Grandison, Jean Guibe, Robert F. Inger, Günther Peters, Gerald Raun, William J. Riemer, Jay M. Savage, Hobart M. Smith, Wilmer W. Tanner, Charles F. Walker, Ernest E. Williams, and Richard G. Zweifel. We are indebted to Charles J. Cole and Charles W. Myers for able assistance in the field. The cooperation of Martin H. Moynihan at Barro Colorado Island, Charles M. Keenan of Corozal, Canal Zone, and Robert Hunter of San José, Costa Rica, is gratefully acknowledged. Jay M. Savage turned over to us many Costa Rican specimens and aided greatly in our work in Costa Rica. James A. Peters helped us locate sites of collections in Ecuador and Coleman J. Goin provided a list of localities for the genus in Colombia. We especially thank Charles J. Cole for contributing the information on the chromosomes, and Robert R. Patterson for preparing osteological specimens. We thank M. J. Fouquette, Jr., who read the section on breeding calls and offered constructive criticism. Permits for collecting were generously provided by Ing. Rodolfo Hernandez Corzo in México, Sr. Jorge A. Ibarra in Guatemala, and Ing. Milton Lopez in Costa Rica. This report was made possible by support from the National Science Foundation (Grants G-9827 and GB-1441) and the cooperation of the Museum of Natural History at the University of Kansas. Some of the field studies were carried out in Panamá under the auspices of a grant from the National Institutes of Health (NIH GM-12020) in cooperation with the Gorgas Memorial Laboratory in Panamá. Materials and Methods In our study we examined 4151 preserved frogs, 93 skeletal preparations, 88 lots of tadpoles and young, and six lots of eggs. We have collected specimens in the field of all of the species. Observations on behavior and life history were begun by the senior author in México in 1956 and completed by us in Central America in 1964 and 1965. Osteological data were obtained from dried skeletons and cleaned and stained specimens of all species, plus serial sections of the skull of _Smilisca baudini_. Developmental stages to which tadpoles are assigned are in accordance with the table of development published by Gosner (1960). Breeding calls were recorded in the field on tape using Magnemite and Uher portable tape recorders. Audiospectrographs were made by means of a Vibralyzer (Kay Electric Company). External morphological features were measured in the manner described by Duellman (1956). In the accounts of the species we have attempted to give a complete synonymy. At the end of each species account the localities from which specimens were examined are listed alphabetically within each state, province, or department, which in turn are listed alphabetically within each country. The countries are arranged from north to south. Abbreviations for museum specimens are listed below: AMNH--American Museum of Natural History BMNH--British Museum (Natural History) BYU--Brigham Young University CNHM--Chicago Natural History Museum KU--University of Kansas Museum of Natural History MCZ--Museum of Comparative Zoology MNHN--Museu National d'Histoire Naturelle, Paris UF--University of Florida Collections UIMNH--University of Illinois Museum of Natural History UMMZ--University of Michigan Museum of Zoology USC--University of Southern California USNM--United States National Museum TNHC--Texas Natural History Collection, University of Texas ZMB--Zoologisches Museum Berlin =Genus Smilisca= Cope, 1865 _Smilisca_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 17:194, Oct., 1865 [Type species _Smilisca daulinia_ Cope, 1865 = _Hyla baudini_ Duméril and Bibron, 1841]. Smith and Taylor, Bull. U. S. Natl. Mus., 194:75, June 17, 1948. Starrett, Copeia, 4:300, December 30, 1960. Goin, Ann. Carnegie Museum, 36:15, July 14, 1961. _Definition._--Medium to large tree frogs having: (1) broad, well ossified skull (consisting of a minimum amount of cartilage and/or secondarily ossified cartilage), (2) no dermal co-ossification, (3) quadratojugal and internasal septum present, (4) large ethmoid, (5) _M. depressor mandibulae_ consisting of two parts, one arising from dorsal fascia and other from posterior arm of squamosal, (6) divided _M. adductor mandibulae_, (7) paired subgular vocal sacs in males, (8) no dermal appendages, (9) pupil horizontally elliptical (10) small amounts of amines and other active substances in skin, (11) chromosome number of N = 12 and 2N = 24, (12) breeding call consisting of poorly modulated, explosive notes, and (13) 2/3 tooth-rows in tadpoles. _Composition of genus._--As defined here the genus _Smilisca_ contains six recognizable species. An alphabetical list of the specific and subspecific names that we consider to be applicable to species of _Smilisca_ recognized herein is given below. Names proposed Valid names _Hyla baudini_ Duméril and Bibron, 1841 = _S. baudini_ _Hyla baudini dolomedes_ Barbour, 1923 = _S. phaeota_ _Hyla beltrani_ Taylor, 1942 = _S. baudini_ _Hyla gabbi_ Cope, 1876 = _S. sordida_ _Hyla labialis_ Peters, 1863 = _S. phaeota_ _Hyla manisorum_ Taylor, 1954 = _S. baudini_ _Hyla muricolor_ Cope, 1862 = _S. baudini_ _Hyla nigripes_ Cope, 1876 = _S. sordida_ _Hyla pansosana_ Brocchi, 1877 = _S. baudini_ _Hyla phaeota_ Cope, 1862 = _S. phaeota_ _Hyla phaeota cyanosticta_ Smith, 1953 = _S. cyanosticta_ _Hyla puma_ Cope, 1885 = _S. puma_ _Hyla salvini_ Boulenger, 1882 = _S. sordida_ _Hyla sordida_ Peters, 1863 = _S. sordida_ _Hyla vanvlietii_ Baird, 1854 = _S. baudini_ _Hyla vociferans_ Baird, 1859 = _S. baudini_ _Hyla wellmanorum_ Taylor, 1952 = _S. puma_ _Distribution of genus._--Most of lowlands of México and Central America, in some places to elevations of nearly 2000 meters, southward from southern Sonora and Río Grande Embayment of Texas, including such continental islands as Isla Cozumel, México, and Isla Popa and Isla Cebaco, Panamá, to northern South America, where known from Caribbean coastal regions and valleys of Río Cauca and Río Magdalena in Colombia, and Pacific slopes of Colombia and northern Ecuador. Key to Adults 1. Larger frogs ([M] to 76 mm., [F] to 90 mm.) having broad flat heads and a dark brown or black postorbital mark encompassing tympanum 2 Smaller frogs ([M] to 45 mm., [F] to 64 mm.) having narrower heads and lacking a dark brown or black postorbital mark encompassing tympanum 4 2. Lips barred; flanks cream-colored with bold brown or black mottling in groin; posterior surfaces of thighs brown with cream-colored flecks _S. baudini_, p. 289 Lips not barred; narrow white labial stripe present; flanks not cream-colored with bold brown or black mottling in groin; posterior surfaces of thighs variable 3 3. Flanks and anterior and posterior surfaces of thighs dark brown with large pale blue spots on flanks and small blue spots on thighs _S. cyanosticta_, p. 303 Flanks cream-colored with fine black venation; posterior surfaces of thighs pale brown with or without darker flecks or small cream-colored spots _S. phaeota_, p. 308 4. Fingers having only vestige of web; diameter of tympanum two-thirds that of eye; dorsum pale yellowish tan with pair of broad dark brown stripes _S. puma_, p. 314 Fingers about one-half webbed; diameter of tympanum about one-half that of eye; dorsum variously marked with spots or blotches 5 5. Snout short, truncate; vocal sacs in breeding males dark gray or brown; blue spots on flanks and posterior surfaces of thighs _S. sila_, p. 318 Snout long, sloping, rounded; vocal sacs in breeding males white; cream-colored or pale blue flecks on flanks and posterior surfaces of thighs _S. sordida_, p. 323 Key to Tadpoles 1. Pond tadpoles; tail about half again as long as body; mouth anteroventral 2 Stream tadpoles; tail about twice as long as body; mouth ventral 5 2. Labial papillae in two rows 3 Labial papillae in one row 4 3. First upper tooth row strongly arched medially; third lower tooth row much shorter than other rows; dorsal fin deepest at about two-thirds length of tail; tail cream-colored with dense gray reticulations _S. puma_, p. 314 First upper tooth row not arched medially; third lower tooth row nearly as long as others; dorsal fin deepest at about one-third length of tail; tail tan with brown flecks and blotches _S. baudini_, p. 289 4. Dorsal fin extending onto body _S. phaeota_, p. 308 Dorsal fin not extending onto body _S. cyanosticta_, p. 303 5. Mouth completely bordered by two rows of papillae; inner margin of upper beak not forming continuous arch with lateral processes; red or reddish brown markings on tail _S. sordida_, p. 323 Median part of upper lip bare; rest of mouth bordered by one row of papillae; inner margin of upper beak forming continuous arch with lateral processes; dark brown markings on tail _S. sila_, p. 318 ACCOUNTS OF SPECIES =Smilisca baudini= (Duméril and Bibron) _Hyla baudini_ Duméril and Bibron, Erpétologie général, 8:564, 1841 [Holotype.--MNHN 4798 from "Mexico;" Baudin collector]. Günther, Catalogue Batrachia Salientia in British Museum, p. 105, 1858. Brocchi, Mission scientifique au Mexique ..., pt. 3, sec. 2, Études sur les batrachiens, p. 29, 1881. Boulenger, Catalogue Batrachia Salientia in British Museum, p. 371, Feb. 1, 1882. Werner, Abhand. Zool.-Bot. Gesell. Wien., 46:8, Sept. 30, 1896. Günther, Biologia Centrali-Americana: Reptilia and Batrachia, p. 270, Sept. 1901. Werner, Abhand. Konigl. Akad. Wiss. Munchen, 22:351, 1903. Cole and Barbour, Bull. Mus. Comp. Zool., 50(5):154, Nov. 1906. Gadow, Through southern México, p. 76, 1908. Ruthven, Zool. Jahr. 32(4):310, 1912. Decker, Zoologica, 2:12, Oct., 1915. Stejneger and Barbour, A checklist of North American amphibians and reptiles, p. 32, 1917. Noble, Bull. Amer. Mus. Nat. Hist., 38(10):341, June 20, 1918. Nieden, Das Tierreich, Amphibia, Anura I, p. 243, June, 1923. Gadow, Jorullo, p. 54, 1930. Dunn and Emlen, Proc. Acad. Nat. Sci. Philadelphia, 84:24, March 22, 1932. Kellogg, Bull. U. S. Natl. Mus., 160:160, March 31, 1932. Martin, Aquarien Berlin, p. 92, 1933. Stuart, Occas. Papers Mus. Zool., Univ. Michigan, 292:7, June 29, 1934; Misc. Publ. Mus. Zool. Univ. Michigan, 29:38, Oct. 1, 1935. Gaige, Carnegie Inst. Washington, 457:293, Feb. 5, 1936. Gaige, Hartweg, and Stuart, Occas. Papers Mus. Zool. Univ. Michigan, 360:5, Nov. 20, 1937. Smith, Occas. Papers Mus. Zool. Univ. Michigan, 388:2, 12, Oct. 31, 1938; Ann. Carnegie Mus., 27:312, March 14, 1939. Taylor, Copeia, 2:98, July 12, 1939. Hartweg and Oliver, Misc. Publ. Mus. Zool. Univ. Michigan, 47:12, July 13, 1940. Schmidt and Stuart, Zool. Ser. Field Mus. Nat. Hist., 24(21):238, August 30, 1941. Schmidt, Zool. Ser. Field Mus. Nat. Hist., 22(8):486, Dec. 30, 1941. Wright and Wright, Handbook of frogs and toads, Ed. 2, p. 134, 1942. Stuart, Occas. Papers Mus. Zool. Univ. Michigan, 471:15, May 17, 1943. Bogert and Oliver, Bull. Amer. Mus. Nat. Hist., 83(6):343, March 30, 1945. Taylor and Smith, Proc. U. S. Natl. Mus., 95(3185): 590, June 30, 1945. Smith, Ward's Nat. Sci. Bull., 1, p. 3, Sept., 1945. Schmidt and Shannon, Fieldiana, Zool. Chicago Nat. Hist. Mus., 31(9):67, Feb. 20, 1947. Stuart, Misc. Publ. Mus. Zool. Univ. Michigan, 69:26, June 12, 1948. Wright and Wright, Handbook of frogs and toads, Ed. 3, p. 298, 1949. Stuart, Contr. Lab. Vert. Biol. Univ. Michigan, 45:22, May, 1950. Mertens, Senckenbergiana, 33:170, June 15, 1952; Abhand. Senckenb. Naturf. Gesell., 487:28, Dec. 1, 1952. Schmidt, A checklist of North American amphibians and reptiles, Ed. 6, p. 69, 1953. Stuart Contr. Lab. Vert. Biol. Univ. Michigan, 68:46, Nov. 1954. Zweifel and Norris, Amer. Midl. Nat., 54(1):232, July 1955. Martin, Amer. Nat., 89:356, Dec. 1955. Duellman, Copeia, 1:49, Feb. 21, 1958. Goin, Herpetologica, 14:119, July 23, 1958. Turner, Herpetologica, 14:192, Dec. 1, 1958. Conant, A field guide to reptiles and amphibians, p. 284, 1958. Duellman, Univ. Kansas Publ., Mus. Nat. Hist., 13(2):59, Aug. 16, 1960; Univ. Kansas Publ., Mus. Nat. Hist., 15(1): 46, Dec. 20, 1961. Porter, Herpetologica, 18:165, Oct. 17, 1962. _Hyla vanvlietii_ Baird, Proc. Acad. Nat. Sci. Philadelphia, 7:61, April 27, 1854 [Holotype.--USNM 3256 from Brownsville, Cameron County, Texas; S. Van Vliet collector]. Baird, United States and Mexican boundary survey, 2:29, 1859. Smith and Taylor, Univ. Kansas Sci. Bull., 33:361, March 20, 1950. Cochran, Bull. U. S. Natl. Mus., 220:60, 1961. _Hyla vociferans_ Baird, United States and Mexican boundary survey, 2:35 1859 [_nomen nudum_]. Diáz de León, Indice de los batracios que se encuentran en la República Mexicana, p. 20, June 1904. _Hyla muricolor_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 14(9):359, 1862 [Holotype.--USNM 25097 from Mirador, Veracruz, México; Charles Sartorius collector]. Smith and Taylor, Univ. Kansas Sci. Bull., 33:349, March 20, 1950. Cochran, Bull. U. S. Natl. Mus., 220:56, 1961. _Smilisca daulinia_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 17:194, Oct. 1865 [Holotype.--"skeleton in private anatomical museum of Hyrtl, Professor of Anatomy in the University of Vienna"]. Smith and Taylor, Univ. Kansas Sci. Bull., 33:347, March 20, 1950. _Smilisca daudinii_ [lapsus for _baudini_], Cope, Proc. Acad. Nat. Sci. Philadelphia, 23, pt. 2:205, 1871. _Smilisca baudini_, Cope, Bull. U. S. Nat. Mus., 1:31, 1875; Jour. Acad. Nat. Sci. Philadelphia, 8, pt. 2:107, 1876; Proc. Amer. Philos. Soc., 18:267, August 11, 1879. Yarrow, Bull. U. S. Nat. Mus., 24:176, July 1, 1882. Cope, Bull. U. S. Nat. Mus., 32:13, 1887; Bull. U. S. Nat. Mus., 34:379, April 9, 1889. Dickerson, The frog book, p. 151, July, 1906. Smith and Taylor, Univ. Kansas Sci. Bull., 33:442, March 20, 1950; Taylor, U. Kan. Sc. Bull., 34:802, Feb. 15, 1952; Univ. Kansas Sci. Bull., 35:794, July 1, 1952. Brattstrom, Herpetologica, 8(3):59, Nov. 1, 1952. Taylor, U. Kan. Sci. Bull., 35:1592, Sept. 10, 1953. Peters, Occas. Papers Mus. Zool. Univ. Michigan, 554:7, June 23, 1954. Duellman, Occas. Papers Mus. Zool. Univ. Michigan, 560:8, Oct. 22, 1954. Chrapliwy and Fugler, Herpetologica, 11:122, July 15, 1955. Smith and Van Gelder, Herpetologica, 11:145, July 15, 1955. Lewis and Johnson, Herpetologica, 11:178, Nov. 30, 1955. Martin, Misc. Publ. Mus. Zool. Univ. Michigan, 101:53, April 15, 1958. Stuart, Contr. Lab. Vert. Biol. Univ. Michigan, 75:17, June, 1958. Minton and Smith, Herpetologica, 17:74, July 11, 1961. Nelson and Hoyt, Herpetologica, 17:216, Oct. 9, 1961. Holman, Copeia, 2:256, July 20, 1962. Stuart, Misc. Publ. Mus. Zool. Univ. Michigan, 122:41, April 2, 1963. Maslin, Herpetologica, 19:124, July 3, 1963. Holman and Birkenholz, Herpetologica, 19:144, July 3, 1963. Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 15(5):228, Oct. 4, 1963. Zweifel, Copeia, 1:206, March 26, 1964. Duellman and Klaas, Copeia, 2:313, June 30, 1964. Davis and Dixon, Herpetologica, 20:225, January 25, 1965. Neill, Bull. Florida State Mus., 9:89, April 9, 1965. _Hyla pansosana_ Brocchi, Bull. Soc. Philom., ser. 7, 1:125, 1877 [Holotype.--MNHN 6313 from Panzós, Alta Verapaz, Guatemala; M. Bocourt collector]; Mission scientifique au Mexique ..., pt. 3, sec. 2, Études sur les batrachiens, p. 34, 1881. _Hyla baudini baudini_, Stejneger and Barbour, A checklist of North American amphibians and reptiles, Ed. 3, p. 34, 1933. Wright and Wright, Handbook of frogs and toads, p. 110, 1933. Stejneger and Barbour, A checklist of North American amphibians and reptiles, Ed. 4, p. 39, 1939; A checklist of North American amphibians and reptiles, Ed. 5, p. 49, 1943. Smith and Laufe, Trans. Kansas Acad. Sci., 48(3):328, Dec. 19, 1945. Peters, Nat. Hist. Misc., 143:7, March 28, 1955. _Hyla beltrani_ Taylor, Univ. Kansas Sci. Bull. 28(14):306, Nov. 15, 1942 [Holotype.--UIMNH 25046 (formerly EHT-HMS 29563) from Tapachula, Chiapas, México; A. Magaña collector]. Smith and Taylor, Bull. U. S. Natl. Mus. 194:87, June 17, 1948; Univ. Kansas Sci. Bull, 33:326, March 20, 1950. Smith, Illinois Biol. Mono., 32:23, May, 1964. _Smilisca baudini baudini_, Smith, Jour. Washington Acad. Sci., 37(11):408, Nov. 15, 1947. Smith and Taylor, Bull. U. S. Natl. Mus., 194:75, June 17, 1948; Univ. Kansas Sci. Bull., 33:347, March 20, 1950. Brown, Baylor Univ. Studies, p. 68, 1950. Smith, Smith, and Werler, Texas Jour. Sci., 4(2):254, June 30, 1952. Smith and Smith, Anales Inst. Biol., 22(2):561, Aug. 7, 1952. Smith and Darling, Herpetologica, 8(3):82, Nov. 1, 1952. Davis and Smith, Herpetologica, 8(4):148, Jan. 30, 1953. Neill and Allen, Publ. Res. Div. Ross Allen's Reptile Inst., 2(1):26, Nov. 10, 1959. Maslin, Univ. Colorado Studies, Biol. Series, 9:4, Feb. 1963. Holman, Herpetologica, 20:48, April 17, 1964. _Hyla manisorum_ Taylor, Univ. Kansas Sci. Bull., 36:630, June 1, 1954 [Holotype.--KU 34927 from Batán, Limón Province, Costa Rica; Edward H. Taylor collector]. Duellman and Berg, Univ. Kansas Publ. Mus. Nat. Hist, 15(4):193, Oct. 26, 1962. _Diagnosis._--Size large ([M] 76 mm., [F] 90 mm.); skull noticeably wider than long, having small frontoparietal fontanelle (roofed with bone in large individuals); postorbital processes long, pointed, curving along posterior border of orbit; squamosal large, contacting maxillary; tarsal fold strong, full length of tarsus; inner metatarsal tubercle large, high, elliptical; hind limbs relatively short, tibia length less than 55 per cent snout-vent length; lips strongly barred with brown and creamy tan; flanks pale cream with bold brown or black reticulations in groin; posterior surfaces of thighs brown with cream-colored flecks; dorsal surfaces of limbs marked with dark brown transverse bands. (Foregoing combination of characters distinguishing _S. baudini_ from any other species in genus.) _Description and Variation._--Considerable variation in size, and in certain proportions and structural characters was observed; variation in some characters seems to show geographic trends, whereas variation in other characters apparently is random. Noticeable variation is evident in coloration, but this will be discussed later. In order to analyze geographic variation in size and proportions, ten adult males from each of 14 samples from various localities throughout the range of the species were measured. Snout-vent length, length of the tibia in relation to snout-vent length, and relative size of the tympanum to the eye are the only measurements and proportions that vary noticeably (Table 1). The largest specimens are from southern Sinaloa; individuals from the Atlantic lowlands of Alta Verapaz in Guatemala, Honduras, and Costa Rica are somewhat smaller, and most specimens from the Pacific lowlands of Central America are slightly smaller than those from the Atlantic lowlands. The smallest males are from the Atlantic lowlands of México, including Tamaulipas, Veracruz, the Yucatán Peninsula, and British Honduras. Table 1.--Geographic Variation in Size and Proportions in Males of Smilisca baudini. (Means in Parentheses Below Observed Ranges; Data Based on 10 Specimens From Each Locality.) ============================+============+==============+============ Locality | Snout-vent | Tibia length/| Tympanum/ | length | snout-vent | eye ----------------------------+------------+--------------+------------ Southern Sinaloa | 62.3-75.9 | 43.2-46.7 | 84.2-94.4 | (68.6) | (44.9) | (87.8) | | | Ocotito, Guerrero | 55.6-64.0 | 46.1-51.2 | 66.7-82.8 | (58.7) | (47.8) | (74.6) | | | Pochutla, Oaxaca | 56.1-65.1 | 44.7-49.4 | 73.0-84.2 | (60.2) | (47.5) | (77.4) | | | San Salvador, El Salvador | 57.0-68.0 | 42.1-46.1 | 74.6-83.3 | (62.1) | (44.9) | (77.6) | | | Managua, Nicaragua | 52.9-63.6 | 45.6-49.4 | 73.7-89.7 | (57.3) | (47.5) | (79.4) | | | Esparta, Costa Rica | 57.6-66.0 | 44.6-49.3 | 65.5-83.6 | (61.3) | (47.3) | (75.2) | | | Ciudad Victoria, Tamaulipas | 50.6-56.9 | 44.5-48.7 | 67.2-84.3 | (53.7) | (46.6) | (73.9) | | | Córdoba, Veracruz | 53.8-63.4 | 43.9-48.4 | 66.1-75.9 | (57.5) | (45.6) | (70.0) | | | Isla del Carmen, Campeche | 47.3-56.6 | 44.7-48.9 | 61.5-72.6 | (50.9) | (47.6) | (65.7) | | | Chichén-Itzá, Yucatán | 49.6-57.1 | 45.2-53.4 | 62.7-80.7 | (53.8) | (49.5) | (72.6) | | | British Honduras | 49.0-59.6 | 47.5-50.7 | 67.9-76.8 | (54.9) | (49.1) | (72.2) | | | Chinajá, Guatemala | 56.8-67.6 | 47.0-51.0 | 70.0-82.8 | (63.2) | (49.5) | (73.6) | | | Atlantidad, Honduras | 52.5-65.1 | 49.8-53.6 | 56.1-76.5 | (57.6) | (51.5) | (67.0) | | | Limón, Costa Rica | 57.7-71.3 | 50.4-52.3 | 63.9-73.0 | (62.4) | (51.2) | (68.5) ----------------------------+------------+--------------+------------ The ratio of the tibia to the snout-vent length varies from 42.1 to 53.6 in the 14 samples analyzed. The average ratio in samples from the Pacific lowlands varies from 44.9 in Sinaloa and El Salvador to 47.8 in Guerrero; on the Gulf lowlands of México the average ratio varies from 45.6 in Veracruz to 47.6 on Isla del Carmen, Campeche. Specimens from the Yucatán Peninsula and the Caribbean lowlands have relatively longer legs; the variation in average ratios ranges from 49.1 in British Honduras to 51.2 in Costa Rica and 51.5 in Honduras. Specimens from southern Sinaloa are outstanding in the large size of the tympanum; the tympanum/eye ratio varies from 84.2 to 94.4 (average 87.8). In most other samples the variation in average ratios ranges from 72.2 to 79.3, but specimens from Veracruz have an average ratio of 70.0; Campeche, 65.7; Honduras, 67.0; and Limón, Costa Rica, 68.5. No noticeable geographic trends in size and proportions are evident. Specimens from southern Sinaloa are extreme in their large size, relatively short tibia, and large tympani, but in size and relative length of the tibia the Sinaloan frogs are approached by specimens from such far-removed localities as San Salvador, El Salvador, and Chinajá, Guatemala. Frogs from the Caribbean lowlands of Honduras and Costa Rica are relatively large and have relatively long tibiae and small tympani. The inner metatarsal tubercle is large and high and its shape varies. The tubercle is most pronounced in specimens from northwestern México, Tamaulipas, and the Pacific lowlands of Central America. Possibly the large tubercle is associated with drier habitats, where perhaps the frogs use the tubercles for digging. The ground color of _Smilisca baudini_ is pale green to brown dorsally and white to creamy yellow ventrally. The dorsum is variously marked with dark brown or dark olive-green spots or blotches (Pl. 6A). In most specimens a dark interorbital bar extends across the head to the lateral edges of the eyelid; usually this bar is connected medially to a large dorsal blotch. There is no tendency for the markings on the dorsum to form transverse bands or longitudinal bars. In specimens from the southern part of the range the dorsal dark markings are often fragmented into small spots, especially posteriorly. The limbs are marked by dark transverse bands, usually three on the forearm, three on the thigh, and three or four on the shank. Transverse bands also are present on the tarsi and proximal segments of the fingers and toes. The webbing on the hands and feet is pale grayish brown. The loreal region and upper lip are pale green or tan; the lip usually is boldly marked with broad vertical dark brown bars, especially evident is the bar beneath the eye. A dark brown or black mark extends from the tympanum to a point above the insertion of the forearm; in some specimens this black mark is narrow or indistinct, but in most individuals it is quite evident. The flanks are pale gray to creamy white with brown or black mottling, which sometimes forms reticulations enclosing white spots. The anterior surfaces of the thighs usually are creamy white with brown mottling, whereas the posterior surfaces of the thighs usually are brown with small cream-colored flecks. A distinct creamy white anal stripe usually is present. Usually, there are no white stripes on the outer edges of the tarsi and forearms. In breeding males the throat is gray. Most variation in coloration does not seem to be correlated with geography. The lips are strongly barred in specimens from throughout the range of the species, except that in some specimens from southern Nicaragua and Costa Rica the lips are pale and in some specimens the vertical bars are indistinct. Six specimens from 7.3 kilometers southwest of Matatán, Sinaloa, are distinctively marked. The dorsum is uniformly grayish green with the only dorsal marks being on the tarsi; canthal and post-tympanic dark marks absent. A broad white labial stripe is present and interrupted by a single vertical dark mark below the eye. A white stripe is present on the outer edge of the foot. The flanks and posterior surfaces of the thighs are creamy white, boldly marked with black. Two specimens from Alta Verapaz, Guatemala (CNHM 21006 from Cobán and UMMZ 90908 from Finca Canihor), are distinctive in having many narrow transverse bands on the limbs and fine reticulations on the flanks. Two specimens from Limón Province, Costa Rica (KU 34927 from Batán and 36789 from Suretka), lack a dorsal pattern; instead these specimens are nearly uniform brown above and have only a few small dark brown spots on the back and lack transverse bands on the limbs. The post-tympanic dark marks and dark mottling on the flanks are absent. Specimens lacking the usual dorsal markings are known from scattered localities on the Caribbean lowlands from Guatemala to Costa Rica. The coloration in life is highly variable; much of the apparent variation is due to metachrosis, for individuals of _Smilisca baudini_ are capable of undergoing drastic and rapid change in coloration. When active at night the frogs usually are pale bright green with olive-green markings, olive-green with brown markings, or pale brown with dark brown markings. The dark markings on the back and dorsal surfaces of the limbs are narrowly outlined by black. The pale area below the eye and just posterior to the broad suborbital dark bar is creamy white, pale green, or ashy gray in life. The presence of this mark is an excellent character by which to identify juveniles of the species. The flanks are creamy yellow, or yellow with brown or black mottling. In most individuals the belly is white, but in specimens from southern El Petén and northern Alta Verapaz, Guatemala, the belly is yellow, especially posteriorly. The iris varies from golden bronze to dull bronze with black reticulations, somewhat darker ventrally. _Natural History._--Throughout most of its range _Smilisca baudini_ occurs in sub-humid habitats; consequently the activity is controlled by the seasonal nature of the rainfall and usually extends from May or June through September. Throughout México and Central America the species is known to call and breed in June, July, and August. Several records indicate that the breeding season in Central America is more lengthy. Gaige, Hartweg, and Stuart (1937:4) noted gravid females collected at El Recreo, Nicaragua, in August and September. Schmidt (1941:486) reported calling males in February in British Honduras. Stuart (1958:17) stated that tadpoles were found in mid-February, juveniles in February and March and half-grown individuals from mid-March to mid-May at Tikal, El Petén, Guatemala. Stuart (1961:74) reported juveniles from Tikal in July, and that individuals were active at night when there had been light rain in the dry season in February and March in El Petén, Guatemala. _Smilisca baudini_ seeks daytime retreats in bromeliads, elephant-ear plants (_Xanthosoma_), and beneath bark or in holes in trees. By far the most utilized retreat in the dry season in parts of the range is beneath the outer sheaths of banana plants. Large numbers of these frogs were found in banana plants at Cuautlapan, Veracruz, in March, 1956, in March and December, 1959. Large breeding congregations of this frog are often found at the time of the first heavy rains in the wet season. Gadow (1908:76) estimated 45,000 frogs at one breeding site in Veracruz. In the vicinity of Tehuantepec, Oaxaca, large numbers of individuals were found around rain pools and roadside ditches in July, 1956, and July, 1958; large concentrations were found near Chinajá, Guatemala, in June, 1960, and near Esparta, Costa Rica in July, 1961. Usually males call from the ground at the edge of the water or not infrequently sit in shallow water, but sometimes males call from bushes and low trees around the water. Stuart (1935:38) recorded individuals calling and breeding throughout the day at La Libertad, Guatemala. _Smilisca baudini_ usually is absent from breeding congregations of hylids; frequently _S. baudini_ breeds alone in small temporary pools separated from large ponds where numerous other species are breeding. In Guerrero and Oaxaca, México, _S. baudini_ breeds in the same ponds with _Rhinophrynus dorsalis_, _Bufo marmoreus_, _Engystomops pustulosus_, and _Diaglena reticulata_, and in the vicinity of Esparta, Costa Rica, _S. baudini_ breeds in ponds with _Bufo coccifer_, _Hyla staufferi_, and _Phrynohyas venulosa_. In nearly all instances the breeding sites of _S. baudini_ are shallow, temporary pools. The breeding call of _Smilisca baudini_ consists of a series of short explosive notes. Each note has a duration of 0.09 to 0.13 seconds; two to 15 notes make up a call group. Individual call groups are spaced from about 15 seconds to several minutes apart. The notes are moderately high-pitched and resemble "wonk-wonk-wonk." Little vibration is discernible in the notes, which have 140 to 195 pulses per second and a dominant frequency of 2400 to 2725 cycles per second (Pl. 10A). The eggs are laid as a surface film on the water in temporary pools. The only membrane enclosing the individual eggs is the vitelline membrane. In ten eggs (KU 62154 from San Salvador, El Salvador) the average diameter of the embryos in first cleavage is 1.3 mm. and of the vitelline membranes, 1.5 mm. Hatchling tadpoles have body lengths of 2.6 to 2.7 mm. and total lengths of 5.1 to 5.4 mm. The body and caudal musculature is brown; the fins are densely flecked with brown. The gills are long and filamentous. Growth and development of tadpoles are summarized in Table 9. A typical tadpole in stage 30 of development (KU 60018 from Chinajá, Alta Verapaz, Guatemala) has a body length of 8.7 mm., a tail length of 13.6 mm., and a total length of 22.3 mm.; body slightly wider than deep; snout rounded dorsally and laterally; eyes widely separated, directed dorsolaterally; nostril about midway between eye and tip of snout; mouth anteroventral; spiracle sinistral, located about midway on length of body and slightly below midline; anal tube dextral; caudal musculature slender, slightly curved upward distally; dorsal fin extending onto body, deepest at about one-third length of tail; depth of dorsal fin slightly more than that of ventral fin at mid-length of tail; dorsal part of body dark brown; pale crescent-shaped mark on posterior part of body; ventral surfaces transparent with scattered brown pigment ventrolaterally, especially below eye; caudal musculature pale tan with a dark brown longitudinal streak on middle of anterior one-third of tail; dorsum of anterior one-third of tail dark brown; brown flecks and blotches on rest of caudal musculature, on all of dorsal fin, and on posterior two-thirds of ventral fin; iris bronze in life (Fig. 11). Mouth small; median third of upper lip bare; rest of mouth bordered by two rows of conical papillae; lateral fold present; tooth rows 2/3; two upper rows about equal in length; second row broadly interrupted medially, three lower rows complete, first and second equal in length, slightly shorter than upper rows; third lower row shortest; first upper row sharply curved anteriorly in midline; upper beak moderately deep, forming a board arch with slender lateral processes; lower beak more slender, broadly V-shaped; both beaks bearing blunt serrations (Fig. 15A). In tadpoles having fully developed mouthparts the tooth-row formula of 2/3 is invariable, but the coloration is highly variable. The color and pattern described above is about average. Some tadpoles are much darker, such as those from 11 kilometers north of Vista Hermosa, Oaxaca, (KU 87639-44), 3.5 kilometers east of Yokdzonot, Yucatán (KU 71720), and 4 kilometers west-southwest Puerto Juárez, Quintana Roo, México (KU 71721), whereas others, notably from 17 kilometers northeast of Juchatengo, Oaxaca, México (KU 87645), are much paler and lack the dark markings on the caudal musculature. The variation in intensity of pigmentation possibly can be correlated with environmental conditions, especially the amount of light. In general, tadpoles that were found in open, sunlit pools are pallid by comparison with those from shaded forest pools. These subjective comparisons were made with preserved specimens; detailed comparative data on living tadpoles are not available. The relative length and depth of the tail are variable; in some individuals the greatest depth of the tail is about at mid-length of the tail, whereas in most specimens the tail is deepest at about one-third its length. The length of the tail relative to the total length is usually 58 to 64 per cent in tadpoles in stages 29 and 30 of development. In some individuals the tail is about 70 per cent of the total length. On the basis of the material examined, these variations in proportions do not show geographical trends. Probably the proportions are a reflection of crowding of the tadpoles in the pools where they are developing or possibly due to water currents or other environmental factors. Stuart (1948:26) described and illustrated the tadpole of _Smilisca baudini_ from Finca Chejel, Alta Verapaz, Guatemala. The description and figures agree with ours, except that the first lower tooth row does not have a sharp angle medially in Stuart's figure. He (1948:27) stated that color in tadpoles from different localities probably varies with soil color and turbidity of water. Maslin (1963:125) described and illustrated tadpoles of _S. baudini_ from Pisté, Yucatán, México. These specimens are heavily pigmented like specimens that we have examined from the Yucatán Peninsula and from other places in the range of the species. Maslin stated that the anal tube is median in the specimens that he examined; we have not studied Maslin's specimens, but all tadpoles of _Smilisca_ that we have examined have a dextral anal tube. Newly metamorphosed young have snout-vent lengths of 12.0 to 15.5 mm. (average 13.4 in 23 specimens). The largest young are from La Libertad, El Petén, Guatemala; these have snout-vent lengths of 14.0 to 15.5 mm. (average 14.5 in five specimens). Young from 11 kilometers north of Vista Hermosa, Oaxaca, México, are the smallest and have snout-vent lengths of 12.0 to 12.5 mm. (average 12.3 in three specimens). Recently metamorphosed young usually are dull olive green above and white below; brown transverse bands are visible on the hind limbs. The labial markings characteristic of the adults are represented only by a creamy white suborbital spot, which is a good diagnostic mark for young of this species. In life the iris is pale gold. _Remarks_: The considerable variation in color and the extensive geographic distribution of _Smilisca baudini_ have resulted in the proposal of eight specific names for the frogs that we consider to represent one species. Duméril and Bibron (1841:564) proposed the name _Hyla baudini_ for a specimen (MNHN 4798) from México. Smith and Taylor (1950:347) restricted the type locality to Córdoba, Veracruz, México, an area where the species occurs in abundance. Baird (1854:61) named _Hyla vanvlieti_ from Brownsville, Texas, and (1859:35) labelled the figures of _Hyla vanvlieti_ [= _Hyla baudini_] on plate 38 as _Hyla vociferans_, a _nomen nudum_. Cope (1862:359) named _Hyla muricolor_ from Mirador, Veracruz, México, and (1865:194) used the name _Smilisca daulinia_ for a skeleton that he employed as the basis for the cranial characters diagnostic of the genus _Smilisca_, as defined by him. Although we cannot be certain, Cope apparently inadvertently used _daulinia_ for _baudini_, just as he used _daudinii_ for _baudini_ (1871:205). Brocchi (1877:125) named _Hyla pansosana_ from Panzos, Alta Verapaz, Guatemala. [Illustration: PLATE 1 A B Dorsal views of skulls of young _Smilisca baudini_: (A) recently metamorphosed young (KU 60026), snout-vent length 12.6 mm. ×23; (B) young (KU 85438), snout-vent length 32.1 mm. ×9.] [Illustration: PLATE 2 A B Skull of adult female _Smilisca baudini_ (KU 68184): (A) Dorsal; (B) Ventral. ×4.5.] [Illustration: PLATE 3 A B C Skull of adult female _Smilisca baudini_ (KU 68184): (A) Lateral; (B) Dorsal view of left mandible; (C) Posterior. ×4.5.] [Illustration: PLATE 4 A B C D E F Palmar views of right hands of _Smilisca_: (A) _S. baudini_ (KU 87177); (B) _S. phaeota_ (KU 64276); (C) _S. cyanosticta_ (KU 87199); (D) _S. sordida_ (KU 91761); (E) _S. puma_ (KU 91716), and (F) _S. sila_ (KU 77408). ×3.] [Illustration: PLATE 5 A B C D E F Ventral aspect of right feet of _Smilisca_: (A) _S. baudini_ (KU 87177); (B) _S. phaeota_ (KU 64276); (C) _S. cyanosticta_ (KU 87199); (D) _S. sordida_ (KU 91761); (E) _S. puma_ (KU 91716), and (F) _S. sila_ (KU 77408). ×3.] [Illustration: PLATE 6 A B C Living _Smilisca_: (A) _S. baudini_ (UMMZ 115179) from 1.7 km. W Xicotencatl, Tamaulipas, México; (B) _S. cyanosticta_ (UMMZ 118163) from Volcán San Martín, Veracruz, México; (C) _S. phaeota_ (KU 64282) from Barranca del Río Sarapiquí, Heredia Prov., Costa Rica. All approx. nat. size.] [Illustration: PLATE 7 A B C Living _Smilisca_: (A) _S. puma_ (KU 65307) from 5.9 km. W. Puerto Viejo, Heredia Prov., Costa Rica; (B) _S. sila_ (KU 77407) from Finca Palosanto, 6 km. WNW El Volcán, Chiriquí, Panamá; (C) _S. sordida_ (KU 64257) from 20 km. WSW San Isidro el General, San José Prov., Costa Rica. All approx. nat. size.] [Illustration: PLATE 8 FIG. 1. Breeding site of _Smilisca baudini_, 4 km. WNW of Esparta, Puntarenas Prov., Costa Rica. FIG. 2. Breeding site of _Smilisca phaeota_, Puerto Viejo, Heredia Prov., Costa Rica.] [Illustration: PLATE 9 FIG. 1. Breeding site of _Smilisca puma_, 7.5 km. W of Puerto Viejo, Heredia Prov., Costa Rica. FIG. 2. Breeding site of _Smilisca sordida_, Río La Vieja, 30 km. E of Palmar Norte, Puntarenas Prov., Costa Rica.] [Illustration: PLATE 10 Audiospectrographs and sections of breeding calls of _Smilisca_: (A) _S. baudini_ (KU Tape No. 74); (B) _S. cyanosticta_ (KU Tape No. 373); (C) _S. phaeota_ (KU Tape No. 79).] [Illustration: PLATE 11 Audiospectrographs and sections of breeding calls of _Smilisca_: (A) _S. puma_ (KU Tape No. 382); (B) _S. sila_ (KU Tape No. 385); (C) _S. sordida_ (KU Tape No. 398).] [Illustration: PLATE 12 Lateral views of the heads of _Smilisca_: (A) _S. baudini_ (KU 87177); (B) _S. sordida_ (KU 91765); (C) _S. phaeota_ (KU 64276); (D) _S. puma_ (KU 91716); (E) _S. cyanosticta_ (KU 87199); (F) _S. sila_ (KU 77408). ×3.2.] Aside from the skeleton referred to as _Smilisca daulinia_ by Cope (1865:194), we have examined each of the types of the species synonymized with _S. baudini_. All unquestionably are representatives of _S. baudini_. Taylor (1942:306) named _Hyla beltrani_ from Tapachula, Chiapas. This specimen (UIMNH 25046) is a small female (snout-vent length, 44 mm.) of _S. baudini_. Taylor (1954:630) named _Hyla manisorum_ from Batán, Limón, Costa Rica. The type (KU 34927) is a large female (snout-vent length, 75.3 mm.) _S. baudini_. In this specimen and a male from Suretka, Costa Rica, the usual dorsal color pattern is absent, but the distinctive curved supraorbital processes, together with other structural features, show that the two specimens are _S. baudini_. _Hyla baudini dolomedes_ Barbour (1923:11), as shown by Dunn (1931a:413), was based on a specimen of _Smilisca phaeota_ from Río Esnápe, Darién, Panamá. [Illustration: FIG. 1. Map showing locality records for _Smilisca baudini_.] _Distribution_.--_Smilisca baudini_ inhabits lowlands and foothills usually covered by xerophytic vegetation or savannas, but in the southern part of its range _baudini_ inhabits tropical evergreen forest. The species ranges throughout the Pacific and Atlantic lowlands of México from southern Sonora and the Río Grande embayment of Texas southward to Costa Rica, where on the Pacific lowlands the range terminates at the southern limits of the arid tropical forest in the vicinity of Esparta; on the Caribbean lowlands the distribution seems to be discontinuous southward to Suretka (Fig. 1). Most localities where the species has been collected are at elevations of less than 1000 meters. Three localities are notably higher; calling males were found at small temporary ponds in pine-oak forest at Linda Vista, 2 kilometers northwest of Pueblo Nuevo Solistahuacán, Chiapas, elevation 1675 meters, and 10 kilometers northwest of Comitán, Chiapas, at an elevation of 1925 meters. Tadpoles and metamorphosing young were obtained from a pond in arid scrub forest, 17 kilometers northeast of Juchatengo, Oaxaca, elevation 1600 meters. Stuart (1954:46) recorded the species at elevations up to 1400 meters in the south-eastern highlands of Guatemala. _Specimens examined._--3006, as follows: UNITED STATES: TEXAS: Cameron County, Brownsville, CNHM 5412-3, 6869, UMMZ 54036, USNM 3256. MEXICO: =Campeche=: Balchacaj, CNHM 102285, 102288, 102291, 102311, UIMNH 30709-22, 30726; Champotón, UMMZ 73172 (2), 73176, 73180; 16 km. E Champotón, UMMZ 73181; 5 km. S Champotón, KU 71369-75; 9 km. S Champotón, KU 71367-8; 10.5 km. S Champotón, KU 71365-6, 71722 (tadpoles), 71723 (yg.); 24 km. S Champotón, UMMZ 73177 (2); Chuina, KU 75101-3; Ciudad del Carmen, UIMNH 30703-8; Dzibalchén, KU 75413-31; Encarnación, CNHM 102282, 102289, 102294-5, 102300, 102306-8, 102312, 102314, 102316-7, 102319, 102322, UIMNH 30727-40, 30836-7; 1 km. W Escárcega, KU 71391-6; 6 km. W Escárcega, KU 71397-403; 7.5 km. W Escárcega, KU 71376-89; 14 km. W Escárcega, KU 71390; 13 km. W, 1 km. N Escárcega, KU 71404; 3 km. N Hopelchén, KU 75410-11; 2 km. NE Hopelchén, KU 75412; Matamoras, CNHM 36573; Pitál, UIMNH 30741; 1 km. SW Puerto Real, Isla del Carmen, KU 71345-64; San José Carpizo, UMMZ 99879; Tres Brazos, CNHM 102284, UIMNH 30723-5; Tuxpeña Camp, UMMZ 73239. =Chiapas=: Acacoyagua, USNM 114487-92; 2 km. W Acacoyagua, USNM 114493-4; 5 km. E Arroyo Minas, UIMNH 9533-7; Berriozabal, UMMZ 119186 (7); Chiapa de Corzo, UMMZ 119185 (2); Cintalapa, UIMNH 50077; Colonia Soconusco, USNM 114495-9; 5 km. W Colonia Soconusco, UMMZ 87885 (7); Comitán, UMMZ 94438; 10 km. NW Comitán, KU 57185; El Suspiro, UMMZ 118819 (11); Escuintla, UMMZ 88271 (7), 88278, 88327, 109233; 6 km. NE Escuintla, UMMZ 87856 (26); 3 km. E Finca Juárez, UIMNH 9538; Finca Prussia, UMMZ 95167; Honduras, UMMZ 94434-7; La Grada, UMMZ 87862; 21 km. S La Trinitaria, UIMNH 9540-1; 14.4 km. SW Las Cruces, KU 64239-44; Palenque, UIMNH 49286, USNM 114473-84; 2 km. NW Pueblo Nuevo Solistahuacán, KU 57182-4, UMMZ 119948 (8), 121514; 1.3 km. N Puerto Madero, KU 57186-9; 4 km. N Puerto Madero, KU 57190-1; 8 km. N Puerto Madero, UMMZ 118379 (2); 12 km. N Puerto Madero, KU 57192; 17.6 km. N Puerto Madero, UMMZ 118378; Rancho Monserrata, UIMNH 9531-2, UMMZ 102266-7; Region Soconusco, UIMNH 33542-56; San Bartola, UIMNH 9519-30; San Gerónimo, UIMNH 30804; San Juanito, USNM 114485-6; San Ricardo, CNHM 102406; Solosuchiapa, KU 75432-3; Tapachula, CNHM 102208, 102219, 102239, 102405, UIMNH 25046, 30802-3; Tonolá, AMNH 531, CNHM 102232, 102416, UIMNH 30805-9, USNM 46760; Tuina, KU 41593 (skeleton); Tuxtla Gutierrez, CNHM 102231, 102248; 6 km. E Tuxtla Gutierrez, UIMNH 9539; 10 km. E Tuxtla Gutierrez, UMMZ 119949. =Chihuahua=: 2.4 km. SW Toquina, KU 47226-7; Riito, KU 47228. =Coahuila=: mountain near Saltillo, UIMNH 30833-4. =Colima=: No specific locality, CNHM 1632; Colima, AMNH 510-11; Hacienda Albarradito, UMMZ 80029 (2); Hacienda del Colomo, AMNH 6208; Los Mezcales, UMMZ 80028; Manzanillo, AMNH 6207, 6209; Paso del Río, CNHM 102207, 102229-30, UIMNH 30819-21, UMMZ 110875 (3); Periquillo, UMMZ 80025 (3), 80026 (14); 1.6 km. SW Pueblo Juárez, UMMZ 115564; Queseria, CNHM 102204, 102216-7, 102224, UIMNH 30816-8, UMMZ 80023 (7), 80024 (7); Santiago, UMMZ 80027; 7.2 km. SW Tecolapa, UMMZ 115184. =Guerrero=: Acahuizotla, UF 1338 (2), 1339-40, UMMZ 119182 (2), 119184; 3 km. S Acahuizotla, KU 87183-7; Acapulco, AMNH 55276, UMMZ 121879 (4), USNM 47909; 3 km. N Acapulco, UMMZ 110127; 8 km. NW Acapulco, UF 11203 (7); 27 km. NE Acapulco, UIMNH 26597-610; Agua del Obispo, CNHM 102214, 102290, 102293, 102310, 102413, KU 60413, 87180-2, UIMNH 30764-6; Atoyca, KU 87175-8; Buena Vista, CNHM 102279, 102304, 102313, 102315, UIMNH 30774; Caculutla, KU 87179; 20 km. S Chilpancingo, CNHM 102242, 102401, 102410-1, 102415; Colonia Buenas Aires, UMMZ 119189; El Limoncito, CNHM 102292, 102303, 102321, 102414; El Treinte, CNHM 102212, 102221, 102237, 102240-1, UIMNH 30783-5, USNM 114508-10; Laguna Coyuca, UMMZ 80960 (2); 3 km. N Mazatlán, UIMNH 30777-9; 9 km. S Mazatlán, CNHM 102209, 102215, 102234, 102246, UIMNH 30781-2; Mexcala, CNHM 102399, 102403, 102409, 106539-40, UIMNH 30775-6; Ocotito, KU 60414-23; 5.4 km. N Ocotito, UMMZ 119181 (4); 1.6 km. N Organos, UIMNH 30752-63; Palo Blanco, CNHM 102283, 102286, 102305, 102320, 102404, UIMNH 30767-70; Pie de la Cuesta, AMNH 55275, 59202-5; Puerto Marquéz, AMNH 59200-1 (13); 5.6 km. S San Andreas de la Cruz, KU 87173-4; San Vincente, KU 87172; Zaculapán, UMMZ 119183. =Hidalgo=: Below Tianguistengo, CNHM 102318. =Jalisco=: Atenqueque, KU 91435-6; 5 km. NE Autlán, UIMNH 30810; 5 km. E Barro de Navidad, UMMZ 110900; Charco Hondo, UMMZ 95247; Puerto Vallarta, UIMNH 41346; between La Huerta and Tecomates, KU 91437; 3 km. SE La Resolana, KU 27619, 27620 (skeleton); 11 km. S, 1.6 km. E Yahualica, KU 29039; Zapotilitic, CNHM 102238. =Michoacán=: Aguililla, UMMZ 119179 (5); Apatzingán, CNHM 38766-90, KU 69101 (skeleton); 7 km. E Apatzingán, UMMZ 112843; 11 km. E Apatzingán, UMMZ 112841 (3); 27 km. S Apatzingán, KU 37621-3; 1.6 km. N Arteaga, UMMZ 119180; Charapendo, UMMZ 112840; Coahuayana, UMMZ 104458; El Sabino, CNHM 102205-6, 102210-1, 102220, 102228, 102233, UIMNH 30822-3; La Placita, UMMZ 104456; La Playa, UMMZ 105163; 30 km. E Nueva Italia, UMMZ 120255 (2); 4 km. S Nueva Italia, UMMZ 112842; Ostula, UMMZ 104457 (4); Salitre de Estopilas, UMMZ 104459; San José de la Montaña, UMMZ 104461 (2); 11 km. S Tumbiscatio, KU 37626; 12 km. S Tzitzio, UMMZ 119178. =Morelos=: 3.5 km. W Cuautlixco, KU 87188-90; 1 km. NE Puente de Ixtla, KU 60393-4; 20 km. S Puente de Ixtla, CNHM 102400, UIMNH 30832; Tequesquitengo, AMNH 52036-9. =Nayarit=: 3 km. S Acaponeta, UMMZ 123030 (4); 56 km. S Esquinapa (Sinaloa), KU 73909; Jesús María, AMNH 58239; San Blas, KU 28087, 37624, 62360-2, USNM 51408; 8.6 km. E San Blas, UMMZ 115185; Tepic, UIMNH 30812-5; 4 km. E Tuxpan, KU 67786; 11 km. SE Tuxpan, UIMNH 7329-31, 7335-59. =Nuevo León=: Galeana, CNHM 34389; Salto de Cola de Caballo, CNHM 30628-31, 30632 (40), 30633-7, 34454-67. =Oaxaca=: 11 km. S Candelaria, UIMNH 9515-8; Cerro San Pedro, 24 km. SW Tehuantepec, UMMZ 82156; Chachalapa, KU 38199; 8 km. S Chiltepec, KU 87191; 12 km. S Chivela, UMMZ 115182; Coyul, USNM 114512; Garza Mora, UIMNH 40967-8; Juchatengo, KU 87193; 17 km. NE Juchatengo, KU 87645 (tadpoles), 87646 (young); Juchitán, USNM 70400; Lagartero, UIMNH 9514; Matías Romero, AMNH 52143-5; 25 km. N Matías Romero, KU 33822-8; 7 km. S Matías Romero, UIMNH 42703; Mirador, AMNH 6277, 13832-9, 13842-55; Mira León, 1.6 km. N Huatulco, UIMNH 9503-4; Mixtequillo, AMNH 13924; Pochutla, KU 57167-81, UIMNH 9505-13; Quiengola, AMNH 51817, 52146; Río del Corte, UIMNH 48677; Río Mono Blanco, UIMNH 36831; Río Sarabia, 5 km. N Sarabia, UMMZ 115180 (4); 2.5 km. N Salina Cruz, KU 57165-6; San Antonio, UIMNH 37286; 5 km. NNW San Gabriel Mixtepec, KU 87192; San Pedro del Istmo, UIMNH 37197; Santo Domingo, USNM 47120-2; 3.7 km. N Sarabia, UMMZ 115181 (3); Tapanatepec, KU 37793 (skeleton), 37794, UIMNH 9542, UMMZ 115183; between Tapanatepec and Zanatepec, UIMNH 42704-25; Tecuane, UMMZ 82163 (3); Tehuantepec, AMNH 52625, 52639, 53470, UMMZ 82157-8, 82159 (9), 82160 (4), 82161 (8), 82162 (12), 112844-5, 118703, USNM 10016, 30171-4, 30188; 4.5 km. W Tehuantepec, KU 59801-12 (skeletons), 69102-3 (skeletons); 10 km. S Tehuantepec, KU 57163-4; Temazcal, USC 8243 (3); 3 km. S Tolocita, KU 39666-9; Tolosa, AMNH 53605; Tuxtepec, UMMZ 122098 (2); 2 km. S Valle Nacional, KU 87194-5; 11 km. N Vista Hermosa, KU 87196, 87639-41 (tadpoles), 87642-3 (young), 87644 (tadpoles); Yetla, KU 87197. =Puebla=: 16 km. SW Mecatepec (Veracruz), UIMNH 3657-8; San Diego, AMNH 57714, USNM 114511; Vegas de Suchil, AMNH 57712; Villa Juárez, UF 11205. =Quintana Roo=: Cóba, CNHM 26937; Esmeralda, UMMZ 113551; 4 km. NNE Felipe Carrillo Puerto, KU 71417-8; Pueblo Nuevo X-Can, KU 71405; 10 km. ENE Pueblo Nuevo X-Can, KU 71406; 4 km. WSW Puerto Juárez, KU 71407-11, 71721 (tadpoles); 12 km. W Puerto Juárez, KU 71412-6; San Miguel, Isla de Cozumel, UMMZ 78542 (6), 78543 (10), 78544 (2); 3.5 km. N San Miguel, Isla de Cozumel, KU 71419-22; 10 km. E San Miguel, Isla de Cozumel, UMMZ 78541; Telantunich, CNHM 26950. =San Luis Potosí=: Ciudad Valles, AMNH 57776-81 (12), CNHM 37193, 102297, KU 23705; 21 km. N Ciudad Valles, UMMZ 118377; 6 km. E Ciudad Valles, UF 3524; 24 km. E Ciudad Valles, UF 7340 (2); 5 km. S Ciudad Valles, UIMNH 30751; 16 km. S Ciudad Valles, AMNH 52953; 30 km. S Ciudad Valles, CNHM 102394, 102402, 102412, UIMNH 30749-50; 63 km. S Ciudad Valles, UIMNH 19247-58; Pujal, UMMZ 99872 (2); Río Axtla, near Axtla, AMNH 53211-5, 59516, KU 23706; Tamazunchale, AMNH 52675, CNHM 39621-2, 102226, 102281, UF 7615 (2), UIMNH 26596, UMMZ 99506 (9), 118701 (2), USNM 114468; 17 km. N Tamazunchale, UIMNH 3659; 2.4 km. S Tamazunchale, AMNH 57743; 17 km. E Tamuin, UF 11202 (2); Xilitla, UIMNH 19259-60. =Sinaloa=: 8 km. N. Carrizalejo, KU 78133; 4 km. NE Concordia, KU 73914; 5 km. SW Concordia, KU 75438-9; 6 km. E Cosalá, KU 73910; Costa Rica, 16 km. S. Culiacán, UIMNH 34887-9; 51 km. SSE Culiacán, KU 37792; El Dorado, KU 60392; 1.6 km. NE El Fuerte, CNHM 71468; Isla Palmito del Verde, middle, KU 73916-7; 21 km. NNE Los Mochis, UIMNH 40536-7; Matatán, KU 73913; 7.3 km. SW Matatán, KU 78464, 78466-70; Mazatlán, AMNH 12562, UMMZ 115197 (3); 57 km. N Mazatlán, UIMNH 38364; Plomosas, USNM 47439-40; Presidio, UIMNH 30811, USNM 14082; Rosario, KU 73911-2; 5 km. E Rosario, UIMNH 7360-76; 8 km. SSE Rosario, KU 37625; 5 km. SW San Ignacio, KU 78465; 1.6 km. ENE San Lorenzo, KU 47917-24; Teacapán, Isla Palmito del Verde, KU 73915; 9.6 km. NNW Teacapán, KU 91410; Villa Unión, KU 78471; 9 km. NE Villa Unión, KU 75434-7; 1 km. W Villa Unión, AMNH 59284. =Sonora=: Guiracoba, AMNH 51225-38 (25). =Tabasco=: 4 km. NE Comalcalco, AMNH 60313; Teapa, UMMZ 119943; 5 km. N Teapa, UMMZ 119940, 119944, 122997 (2); 10 km. N Teapa, UMMZ 119187, 119188 (2); 13 km. N Teapa, UMMZ 119941 (2), 119945 (3), 120254 (2); 21 km. N Teapa, UMMZ 119942, 119947; 29 km. N Teapa, UMMZ 119946 (11); Tenosique, USNM 114505-7. =Tamaulipas=: Acuña, UMMZ 99864; 5 km. S Acuña, UMMZ 101180; 13 km. N Antiguo Morelos, UIMNH 40532-5; 3 km. S Antiguo Morelos, UF 11204; 3 km. NE Chamal, UMMZ 102867; 1.6 km. E Chamal, UMMZ 110734; Ciudad Mante, UMMZ 80957, 80958 (3), 106400 (3); 16 km. N Ciudad Victoria, CNHM 102408; 34 km. NE Ciudad Victoria, KU 60395-411; 8.8 km. S Ciudad Victoria, UIMNH 19261-3; 11 km. W Ciudad Victoria, UIMNH 30924; 16 km. W Ciudad Victoria, UIMNH 30825; 3 km. W El Carizo, UMMZ 111279; Gómez Farías, UMMZ 110837-8; 8 km. NE Gómez Farías, UMMZ 102265, 102916 (4), 102917, 104110 (5), 105493, 110836 (2), 111274-7; 8 km. NW Gómez Farías, UMMZ 101178 (7), 101179 (3), 101362-3, 101364 (2), 108799 (2), 110129, 111278, 111280; 8 km. W Gómez Farías, UMMZ 102859 (2); 16 km. W Gonzales, KU 37795-6; Jiménez, KU 60412; La Clementina, 6 km. W Forlan, USNM 106244; Limón, UIMNH 30831; Llera, USNM 140137-40; 3 km. E Llera, UIMNH 16858; 21 km. S Llera, UIMNH 30828-9; 23 km. S Llera, UIMNH 30830; 11 km. SW Ocampo, UMMZ 118956; 22 km. W, 5 km. S Piedra, KU 37568-71; Rio Sabinas, UMMZ 97976; 5 km. W San Gerardo, UMMZ 110733 (2); Santa Barbara, UMMZ 111272-3; Villagrán, CNHM 102280, 102287, 102299, 102309, UIMNH 30826-7; 1.7 km. W Xicotencatl, UMMZ 115179. =Veracruz=: 1.6 km. NW Acayucan, UMMZ 115189; 28.5 km. SE Alvarado, UMMZ 119933; 2.4 km. SSW Amatitlán, UMMZ 115195; Barranca Metlac, UIMNH 38365; Boca del Río, UIMNH 26619-30, UMMZ 74954 (9); 16 km. S Boca del Río, UIMNH 26631; between Boca del Río and Anton Lizardo, UIMNH 42701; Canadá, CNHM 102397; Catemaco, UMMZ 118702 (4); Ciudad Alemán, UMMZ 119608 (3); Córdoba, CNHM 38665-7, USNM 30410-3; 5.2 km. ESE Córdoba, KU 71423-35, 89924 (skeleton); 7 km. ESE Córdoba, UMMZ 115176 (4); Cosamaloapan, UMMZ 115193 (2); Coyame, UIMNH 36853-6, 38366, UMMZ 111461 (3), 111462-3; 1 km. SE Coyame, UMMZ 121202 (3); Cuatotolapam, UMMZ 41625-39; Cuautlapan, CNHM 38664, 70591-600, 102218, 102398, KU 26300, 26302, 26309, 26312-3, 26315-6, 26321, 26336, 26339, 26347 (skeleton), 26354, 55614-21 (skeletons), UIMNH 11236-67, 11269-71, 11273, 26611-8, 30792-5, UMMZ 85466 (6), 115173 (25), 115175 (7), USNM 114433-57; Dos Ríos, CNHM 39623; 5 km. ENE El Jobo, KU 23843, 23845, 23847; 6.2 km. E Encero, UIMNH 30835; Escamilo, CNHM 102298, UIMNH 30788; 1 km. N Fortín, UF 11201; 4 km. SW Huatusco, UMMZ 115177; 1 km. SW Huatusco, UMMZ 123119; 10 km. SE Hueyapan, UMMZ 115190; 20 km. S Jesús Carranza, KU 23844, 23846, 27399; 38 km. SE Jesús Carranza, KU 23417; Laguna Catemaco, UMMZ 119932 (62); 1.6 km. N La Laja, UIMNH 3651; La Oaxaqueña, AMNH 43930-1; 17 km. E Martínez de la Torre, UIMNH 36630-2; 6.2 km. W Martínez de la Torre, UIMNH 3652-4; Minatitlán, AMNH 52141-2; Mirador, USNM 25097-8, 115178; 6 km. S Monte Blanco, UF 11200 (4); 21 km. E Nanchital, UMMZ 123004; 2 km. S Naranja, UMMZ 115188 (3); 1.6 km. NE Novillero, UMMZ 115194 (2); 3 km. NE Novillero, UMMZ 115196; 5.2 km. NE Novillero, UMMZ 115192 (4); 6 km. NE Novillero, UMMZ 115191; 5 km. N Nuevo Colonia, UMMZ 105066; Orizaba, USNM 16563-6; 4 km. NE Orizaba, UMMZ 120251 (2); Panuco, UMMZ 118922; Paraje Nuevo, UMMZ 85465 (2), 85467 (35), 85468 (36); Paso del Macho, UIMNH 49281; Paso de Talaya, Jicaltepec, USNM 32365, 84420; Pérez, CNHM 1686 (5); 20 km. N Piedras Negras, Río Blanco, KU 23708; Plan del Río, KU 26310, 26333-5, 26345, 26354, UMMZ 102069, 102070 (5); Potrero, UIMNH 49282-5, UMMZ 88799, 88805, 88806 (2), USNM 32391-5; Potrero Viejo, CNHM 102296, KU 26301, 26304-5, 26307-8, 26311, 26317-20, 26323-25, 26326-8 (skeletons), 26329-31, 26332 (skeleton), 26337-8, 26340-4, 26346, 26348, 26351, 26353, 27400-12, UIMNH 30800, UMMZ 88800 (2), 88802 (15), 88803 (9), 88804, USNM 114458-67; 5 km. S Potrero Viejo, KU 26303, 26314, 26322; Puente Nacional, UIMNH 21783-8; 3 km. N Rinconada, UMMZ 122099 (5); Río de las Playas, USNM 118635-6; Río Seco, UMMZ 88801 (9); Rodriguez Clara, CNHM 102225; San Andrés Tuxtla, CNHM 102213, 102222, 102227, 102247, UIMNH 30789-91; 10 km. NW San Andrés Tuxtla, UMMZ 119935; 13.4 km. NW San Andrés Tuxtla, UMMZ 119939 (2); 19.8 km. NW San Andrés Tuxtla, UMMZ 119938; 27.2 km. NW San Andrés Tuxtla, UMMZ 119936 (6); 48 km. NW San Andrés Tuxtla, UMMZ 119937; 4 km. W San Andrés Tuxtla, UMMZ 115187; 37.4 km. S San Andrés Tuxtla, UMMZ 119934 (12); 15 km. ESE San Juan de la Punta, KU 23707; San Lorenzo, USNM 123508-12; 3 km. SW San Marcias KU 23841; 1.5 km. S Santa Rosa, UIMNH 42702; 2 km. S Santiago Tuxtla, UMMZ 121201 (4); Sauzel, UMMZ 121239; 14 km. E Suchil, UIMNH 46880; 15 km. S Tampico (Tamaulipas), UMMZ 103322 (4); 4 km. N Tapalapan, UMMZ 115186 (2); Tecolutla, UIMNH 42677-700; 16 km. NW Tehuatlán, UIMNH 3660-3; 5 km. S Tehuatlán, KU 23842; Teocelo, KU 26306; Tierra Colorado, CNHM 102393, 102395-6, UIMNH 30789-91; Veracruz, AMNH 6301-4, 59398-402, UIMNH 30801, UMMZ 115174, 122060 (2); 24 km. W Veracruz, CNHM 104570-2. =Yucatán=: No specific locality, CNHM 548, 49067, USNM 32298; Chichén-Itzá, CNHM 20636, 26938-49, 36559-62, UIMNH 30742-6, UMMZ 73173 (6), 73174 (14), 73175 (14), 73178-9, 76171, 83107 (2), 83108, 83109 (2), 83915 (30), USNM 72744; 9 km. E Chichén-Itzá, KU 71438-9; 12 km. E Chichén-Itzá, KU 71440; Mérida, CNHM 40659-66, UIMNH 30747-8, UMMZ 73182; 6 km. S Mérida, KU 75194; 8.8 km. SE Ticul, UMMZ 114296; Valladolid, CNHM 26934-6; Xcalah-op, CNHM 53906-14; 3.5 km. E Yokdzonot, KU 71441-3, 71720 (tadpoles). BRITISH HONDURAS: Belize, CNHM 4153, 4384-5, 4387, UMMZ 75310, USNM 26065; Bokowina, CNHM 49064-5; Cocquercote, UMMZ 75331 (2); Cohune Ridge, UMMZ 80738 (15); Double Falls, CNHM 49066; El Cayo, UMMZ 75311; 6 km. S El Cayo, MCZ 37856; Gallon Jug, MCZ 37848-55; Manatee, CNHM 4264-7; Mountain Pine Ridge, MCZ 37857-8; San Augustin, UMMZ 80739; San Pedro, Columbia, MCZ 37860-2; Valentin, UMMZ 80735 (4), 80736 (2), 80737 (2); 5 km. S Waha Loaf Creek, MCZ 37859. GUATEMALA: =Alta Verapaz=: 5.1 km. NE Campur, KU 68464 (tadpoles), 67465 (young); 28.3 km. NE Campur, KU 64203-22, 68183-4 (skeletons); Chamá, MCZ 15792-3, UMMZ 90895 (7), 90896 (5), 90897 (29), 90898 (12), 90899; Chinajá, KU 55939-41, 57193-8, 60018-20 (tadpoles), 60021 (eggs), 60022 (tadpoles); Cobán, CNHM 21006; Cubilquitz, UMMZ 90902 (10); Finca Canihor, UMMZ 90908; Finca Chicoyou, KU 57246-8, 60026 (young), 64202, 68466-7 (tadpoles); Finca Los Alpes, KU 64197-201, 68463 (tadpoles); Finca Los Pinales, UMMZ 90903 (2); Finca Tinajas, BYU 16031; Finca Volcán, UMMZ 90905 (4), 90906-7; Panzos, MNHN 6313, UMMZ 90904; Samac, UMMZ 90900; Samanzana, UMMZ 90901 (6). =Baja Verapaz=: Chejel, UMMZ 90909 (7), 90910 (3); San Gerónimo, UMMZ 84076 (16). =Chiquimula=: 1.6 km. SE Chiquimula, UMMZ 98112; Esquipulas, UMMZ 106793 (28). =El Petén=: 20 km. NNW Chinajá (Alta Verapaz), KU 57199-240; Flores, UMMZ 117985; La Libertad, KU 60024 (young), UMMZ 75313-20, 75323 (2), 75324 (7), 75325 (13), 75326 (2), 75327 (11), 75328 (12), 75329 (2); 3 km. SE La Libertad, KU 57243-4; 13 km. S La Libertad, MCZ 21458 (2); Pacomon, USNM 71334; Piedras Negras, USNM 114469-71; Poptún, UMMZ 120475; Poza de la Jicotea, USNM 114672; Ramate-Yaxha trail, UMMZ 75321; Río de la Pasión between Sayaxché and Subín, KU 57151; Río San Román, 16 km. NNW Chinajá (Alta Verapaz), KU 55942-6; Sacluc, USNM 25131; Sayaxché, KU 57144-5; Tikal, UMMZ 117983 (7), 117984 (5), 117993 (5), 120474 (5); Toocog, KU 57241-2, 60023 (young), 60025 (young); Uaxactún, UMMZ 70401-3; Yaxha, UMMZ 75322; 19 km. E Yaxha, UMMZ 75330 (4). =El Quiché=: Finca Tesoro, UMMZ 89166 (3), 90549 (tadpoles). =Escuintla=: Río Guacalate, Masagua, USNM 125239; Tiquisate, UMMZ 98262 (7). =Guatemala=: 16 km. NE Guatemala, KU 43545-53. =Huehuetenango=: Finca San Rafael, 16 km. SE Barillas, CNHM 40912-6; 45 km. WNW Huehuetenango, KU 64223-4; Jacaltenango, UMMZ 120080 (6), 120081 (14), 120082 (13). =Izabál=: 2 km. SW Puerto Matías de Gálvez, KU 60027-8 (tadpoles); Quiriguá, CNHM 20587, UMMZ 70060. =Jalapa=: Jalapa, UMMZ 98109, 106792 (11). =Jutiapa=: Finca La Trinidad, UMMZ 107728 (10); Jutiapa, UMMZ 106789; 1.6 km. SE Mongoy, KU 43069; Santa Catarina Mita, UMMZ 106790. =Progreso=: Finca Los Leones, UMMZ 106791. =Quetzaltenango=: Coatepeque, AMNH 62204. =Retalhueleu=: Casa Blanca, UMMZ 107725 (18); Champerico, UMMZ 107726 (3). =San Marcos=: Talisman Bridge, USNM 128056-7. =Santa Rosa=: Finca La Guardiana, UMMZ 107727 (6); Finca La Gloria, UMMZ 107724 (6); 1.6 km. WSW El Molino, KU 43065-8. EL SALVADOR: =La Libertad=: 16 km. NW Santa Tecla, KU 43542-4. =Morazán=: Divisadero, USNM 73284. =San Salvador=: San Salvador, CNHM 65087-99, KU 61955-88, 62138-9 (skeletons), 62154 (eggs), 62155-60 (tadpoles), 68462 (tadpoles), UMMZ 117586 (3), 118380 (3), USNM 140278. HONDURAS: State unknown: Guaimas, UMMZ 58391. =Atlantidad=: Isla de Roatán, CNHM 34551-4; La Ceiba, USNM 64985, 117589-91; Lancetilla, MCZ 16207-11; Tela, MCZ 15774-5, 28080, UMMZ 58418, USNM 82173-4. =Choluteca=: 1.5 km. NW Choluteca, KU 64228-32; 10 km. NW Choluteca, KU 64233; 10 km. E Choluteca, KU 64226-7; 12 km. E Choluteca, KU 64225; 5 km. S Choluteca, USC 2700 (2). =Colón=: Bambú, UF 320; Belfate, AMNH 45692-5; Patuca, USNM 20261. =Comayagua=: La Misión, 3.5 leagues N Siguatepeque, MCZ 26424-5. =Copán=: Copán, UMMZ 83026 (2). =Cortés=: Cofradía, AMNH 45345-6; Hacienda Santa Ana, CNHM 4724-31; Lago de Yojoa, MCZ 26410-1; Río Lindo, AMNH 54972. =El Paraiso=: El Volcán, MCZ 26436. =Francisco Morazán=: Tegucigalapa, BYU 18301-4, 18837-41, MCZ 26395-7, USNM 60499. =Gracias A Dios=: Río Segovia, MCZ 24543. =Santa Barbara=: Santa Barbara, USNM 128062-5. NICARAGUA: =Chinandega=: 4 km. N, 2 km. W Chichigalpa, KU 85385; Chinandega, MCZ 2632; Río Tama, USNM 40022; San Antonio, KU 84944-9 (skeletons), 85386-403. =Chontales=: 1 km. NE Acoyapa, KU 64234. =Estelí=: Finca Daraili, 5 km. N, 15 km. E Condega, KU 85404-8; Finca Venecia, 7 km. N, 16 km. E Condega, KU 85409. =León=: 1.6 km. ENE Poneloya, KU 43084-5. =Managua=: Managua, USNM 79989-90; 8 km. NW Managua, KU 43094-110; 20 km. NE Managua, KU 85412; 21 km. NE Managua, KU 85413-4; 5 km. SW Managua, KU 43086-93; 2 km. N Sabana Grande, KU 85411; 3 km. N Sabana Grande, KU 43070-8; 20 km. S, 0.5 km. W Tipitapa, KU 85410. =Matagalpa=: Guasqualie, UMMZ 116493; Matagalpa, UMMZ 116492; 19 km. N Matagalpa, UMMZ 116494. =Río San Juan=: Greytown, USNM 19585-6, 19767-8. =Rivas=: Javillo, UMMZ 123001; Moyogalpa, Isla Ometepe, KU 85428-37, 87706 (tadpoles); Peñas Blancas, KU 85417; Río Javillo, 3 km. N, 4 km. W Sapoá, KU 85418-20, 85438 (skeleton); 13.1 km. SE Rivas, KU 85415; 14.8 km. SE Rivas, KU 85421-3; 11 km. S, 3 km. E Rivas, KU 85416; 16 km. S Rivas, MCZ 29009-10; 7.7 km. NE San Juan del Sur, KU 85426-7; 16.5 km. NE San Juan del Sur, KU 85424-5, 87705 (young); 5 km. SE San Pablo, KU 43079-83. =Zelaya=: Cooley, AMNM 7063-8, 8019-20, 8022, 8034-5; Cukra, AMNH 8016-7; Musahuas, Río Huaspuc, AMNH 58428-31; 11 km. NW Rama, Río Siquia, UMMZ 79708, 79709 (5), 79710 (2); Río Escondido, USNM 19766, 20701; Río Siquia at Río Mico, UMMZ 79707 (10); Sioux Plantation, AMNH 7058-61, 8023-33. COSTA RICA: =Alajuela=: Los Chiles, AMNH 54639; Orotina, MCZ 7960-1; San Carlos, USNM 29991. =Guanacaste=: La Cruz, USC 8232 (3); 4.3 km. NE La Cruz, UMMZ 123002; 18.4 km. S La Cruz, USC 8136; 23.5 km. S La Cruz, USC 8094 (4); 3 km. W La Cruz, USC 8233 (4); 2 km. NE Las Cañas, KU 64235-7; Las Huecas, UMMZ 71212-3; Liberia, KU 36787, USC 8161; 11.5 km. N Liberia, USC 8149; 13 km. N Liberia, USC 8139; 22.4 km. N Liberia, USC 8126; 8 km. NNW Liberia, KU 64238; 8.6 km. ESE Playa del Coco, USC 8137; 21.8 km. ESE Playa del Coco, USC 8138; Río Piedra, 1.6 km. W Bagaces, USC 7027; Río Bebedero, 5 km. S Bebedero, KU 64158; 5 km. NE Tilarán, KU 36782-6. =Heredia=: 13 km. SW Puerto Viejo, KU 64142-6. =Limón=: Batán, KU 34927; Guacimo, USC 621; Pandora, USC 505 (3); Suretka, KU 36788-9; Tortugero, UF 7697, 10540-2. =Puntarenas=: Barranca, CNHM 35254-6; 15 km. WNW Barranca, KU 64155-7, UMMZ 118381; 18 km. WNW Barranca, UMMZ 118382 (4); 4 km. WNW Esparta, KU 64159-96, 68178-82 (skeletons); 19 km. NW Esparta, KU 64147-54. =Smilisca cyanosticta= (Smith), new combination _Hyla phaeota_, Taylor, Univ. Kansas Sci. Bull., 28(5):80, May 15, 1942. Taylor and Smith, Proc. U. S. Natl. Mus., 95(3185):589, June 30, 1945. _Hyla phaeota cyanosticta_ Smith, Herpetologica, 8:150, Jan. 30, 1953 [Holotype.--USNM 111147 from Piedras Negras, El Petén, Guatemala; Hobart M. Smith collector]. Shannon and Werler, Trans. Kansas Acad. Sci., 58:386, Sept. 24, 1955. Poglayen and Smith, Herpetologica, 14:11, April 25, 1958. Cochran, Bull. U. S. Natl. Mus., 220:57, 1961. Smith, Illinois Biol. Mono., 32:25, May, 1964. _Smilisca phaeota cyanosticta_, Stuart, Misc. Publ. Mus. Zool. Univ. Michigan, 122:42, April 2, 1963. Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 15(5):229, Oct. 4, 1963. _Diagnosis._--Size moderately large ([M] 56.0 mm., [F] 70.0 mm.); skull as long as wide; frontoparietal fontanelle large; narrow supraorbital flanges having irregular margins anteriorly; large squamosal not in contact with maxillary; tarsal fold moderately wide, full length of tarsus; inner metatarsal tubercle moderately large, low, flat, elliptical; hind limbs relatively long; tibia usually more than 52 per cent of snout-vent length; labial stripe silvery-white; lips lacking vertical bars; loreal region pale green; pale bronze-colored stripe from nostril along edge of eyelid to point above tympanum narrow, bordered below by narrow dark brown stripe from nostril to eye, and broad dark brown postorbital mark encompassing tympanum and terminating above insertion of arm; flanks, dark brown with large pale blue spots; anterior and posterior surfaces of thighs dark brown with small pale blue spots on thighs. (Foregoing combination of characters distinguishing _S. cyanosticta_ from any other species in genus.) _Description and Variation._--The largest males are from Piedras Negras, El Petén, Guatemala, and they average 52.5 mm. in snout-vent length whereas males from Los Tuxtlas, Veracruz, average 50.6 mm. and those from northern Oaxaca 50.3 mm. The smallest breeding male has a snout-vent length of 44.6 mm. The average ratio of tibia length to snout-vent length is 54.8 per cent in males from Piedras Negras, and 56.4 and 56.3 per cent in males from Los Tuxtlas and Oaxaca, respectively. The only other character showing noticeable geographic variation is the size of the tympanum. The average ratio of the diameter of the tympanum to the diameter of the eye is 76.3 per cent in males from Piedras Negras, 71.8 from Oaxaca, and 66.9 from Los Tuxtlas. The dorsal ground color of _Smilisca cyanosticta_ is pale green to tan and the venter is creamy white. The dorsum is variously marked with dark olive-green or dark brown spots or blotches (Pl. 6B). An interorbital dark bar usually is present. The most extensive dark area is a V-shaped mark in the occipital region with the anterior branches not reaching the eyelids; this mark is continuous, by means of a narrow mid-dorsal mark, with an inverted V-shaped mark in the sacral region. In many specimens this dorsal marking is interrupted, resulting in irregular spots. In some specimens the dorsum is nearly uniform pale green or tan with a few small, dark spots. The hind limbs are marked by dark transverse bands, usually three or four each on the thigh and shank, and two or three on the tarsus. The webbing on the feet is brown. The loreal region is pale green, bordered above by a narrow, dark brown canthal stripe extending from the nostril to the orbit, which is bordered above by a narrow, bronze-colored stripe extending from the nostril along the edge of the eyelid to a point above the tympanum. The upper lip is white. A broad dark brown mark extends posteriorly from the orbit and encompasses the tympanum to a point above the insertion of the forelimb. The flanks are dark brown with many pale blue, rounded spots, giving the impression of a pale blue ground color with dark brown mottling enclosing spots. The anterior and posterior surfaces of the thighs are dark brown with many small pale blue spots. The inner surfaces of the shank and tarsus are colored like the posterior surfaces of the thighs. Pale blue spots are usually present on the proximal segments of the second and third toes. A distinct white stripe is present on the outer edge of the tarsus and fifth toe; on the tarsus the white stripe is bordered below by dark brown. A white stripe also is present on the outer edge of the forearm and fourth finger. The anal region is dark brown, bordered above by a narrow transverse white stripe. The throat in breeding males is dark, grayish brown with white flecks. No geographic variation in the dorsal coloration is evident. Specimens from the eastern part of the range (Piedras Negras and Chinajá, Guatemala) have bold, dark reticulations on the flanks enclosing large pale blue or pale green spots, which fade to tan in preservative. Specimens from Oaxaca and Veracruz characteristically have finer dark reticulations on the flanks enclosing smaller blue spots; in many of these specimens the ventrolateral spots are smallest and are white. All living adults are easily recognized by the presence of pale, usually blue, spots on the flanks and thighs. Individuals under cover by day have a tan dorsum with dark brown markings. A hiding individual at Chinajá, Alta Verapaz, Guatemala (KU 55936), had a pale tan dorsum when found; later the dorsal color changed to chocolate brown. A pale green patch was present below the eye; the spots on the posterior surfaces of the thighs were pale blue, and those on the flanks were yellowish green. A calling male obtained 10 kilometers north-northwest of Chinajá (KU 55934) was reddish brown when found at night; later the dorsal color changed to pale tan. A green patch below the eye was persistent. Usually these frogs are green at night. The coloration of an adult male (KU 87201) from 11 kilometers north of Vista Hermosa, Oaxaca, México, was typical: "When calling dorsum pale green; later changed to dull olive-green. Flanks dark brown with pale blue spots in axilla and groin and bluish white flecks on mid-flank. Anterior and posterior surfaces of thighs, inner surfaces of shanks, and median dorsal surfaces of tarsi dark brown with blue spots. Canthal and postorbital stripes dark chocolate brown; labial stripe creamy white. Forearm, tarsal, and anal stripes pale cream-color. Throat dark brown with yellow flecks; belly and ventral surfaces of limbs creamy buff; webs pinkish tan; iris deep bronze, brown below pupil." (Duellman, field notes, June 24, 1964.) Some individuals have both green and brown coloration in life. An individual obtained at night on the south slope of Volcán San Martín, Veracruz, México, had a pale tan dorsum changing peripherally to pale green. The dorsal markings were dark brown and dark olive-green. In contrast to the color-changes noted above, the labial region below the eye is always pale green, and pale spots are always present on the flanks and thighs in adults. The iris is invariably golden or bronze above and darker, usually brown, below. Minute black flecks are present on the iris, and in some individuals these flecks are so numerous that the eye appears gray. Recently metamorphosed young have pale tan flanks, and the posterior surfaces of the thighs are orange-yellow; pale spots are absent. A juvenile (KU 55935) from Chinajá, Alta Verapaz, Guatemala, having a snout-vent length of 35.0 mm. was pale yellowish tan above with olive-green markings; the flanks were dark brown with pale blue spots, and the anterior and posterior surfaces of the thighs were uniform bright tomato red. A juvenile (UMMZ 121298), 18.6 mm. in snout-vent length, from the southeast slope of Volcán San Martín, Veracruz, México, had pale tan flanks lacking blue spots, but had red thighs. Apparently the ontogenetic changes in coloration proceed as follows: (1) flanks pale tan and thighs orange-yellow, both lacking spots, (2) flanks pale tan and thighs red, both lacking spots, (3) flanks dark brown with blue spots and thighs red, lacking spots, and (4) flanks and thighs dark brown, both having pale blue spots. _Natural History._--_Smilisca cyanosticta_ inhabits humid tropical forest and cloud forest from the lowlands to elevations of about 1200 meters in Los Tuxtlas and to about 900 meters in northern Oaxaca. In these moist environments the frogs apparently are active throughout the year. Active individuals have been obtained in January, July, and August in Los Tuxtlas, Veracruz, in June and July in northern Oaxaca, in February and March at Chinajá, Guatemala, and Taylor and Smith reported (1945:589) activity in May at Piedras Negras, Guatemala. Calling males were observed as follows; in a rain barrel 11 kilometers north of Vista Hermosa, Oaxaca, México, on June 23-28, 1964; in a quiet pool in a stream 8 kilometers south of Yetla, Oaxaca, México, in July, 1963 (Dale L. Hoyt, personal communication); in and near springs flowing into a stream at Dos Amates, Veracruz, México, on August 4, 1959 (Douglas Robinson, personal communication); and in a water-filled depression in a log 10 kilometers west-northwest of Chinajá, Guatemala, on March 13, 1960. Taylor and Smith (1945:589) reported that individuals were found at night on the ground at the edge of temporary pools at Piedras Negras, Guatemala, on May 28-29, 1939. A clasping pair was found on a rock at the edge of a small stream on the south slope of Volcán San Martín, Veracruz, México, on July 11, 1959 (Douglas Robinson, personal communication). Only one individual has been observed in a tree at night. In the daytime, individuals were found in elephant ear plants (_Xanthosoma_) at Chinajá, Guatemala. The breeding call consists of one or two moderately short notes that are lower pitched than those of _S. baudini_, but higher pitched than those of _S. phaeota_. Each note has a duration of 0.25 to 0.45 seconds and is repeated at intervals of one-half minute to several minutes. Each note is a vibrant "waunk," having 110 to 180 pulses per second and dominant frequency of 1600 to 2100 cycles per second (Pl. 10B). Apparently the eggs are deposited as loose clumps in the water. In eggs in the yolk plug stage of development, the diameter of the embryo is about 2.3 mm.; that of the outer envelope is 4.0 mm. Hatchling tadpoles have total lengths of 5.8 to 6.5 mm. and body lengths of 2.8 to 3.1 mm. The external gills are moderately long, slender, and filamentous; the yolk sac is still moderately large. The body and anterior part of the caudal musculature are dark brown; posteriorly the caudal musculature is pale brown. The caudal fins are creamy tan. The oral discs are large and ovoid. The growth of the tadpole is summarized in Table 10. A typical tadpole in stage 30 of development (KU 87652 from 11 km. N Vista Hermosa, Oaxaca, México) can be described as follows: Body length 9.5 mm.; tail length 15.5 mm.; total length 25.0 mm.; body slightly wider than deep; snout rounded laterally, broadly ovoid dorsally; eyes widely separated, directed dorsolaterally; nostril about midway between eye and tip of snout; mouth anteroventral; spiracle sinistral, slightly posterior to midpoint of body and slightly below midline; anal tube dextral; caudal musculature slender, barely curved upward distally; dorsal fin not extending onto body, depth of dorsal fin slightly more than that of ventral fin on mid-length of tail; dorsal part of body dark brown; ventral surfaces transparent, lacking pigment; posterior edge of body pale cream-color; caudal musculature creamy white with interconnected brown spots; caudal fins transparent with small brown blotches on dorsal fin and posterior half of ventral fin; iris coppery bronze in life (Fig. 12). Mouth small, median part of upper lip bare; rest of mouth bordered by single row of bluntly rounded papillae; lateral fold present; tooth rows 2/3; all tooth-rows approximately equal in length; second upper row broadly interrupted medially; other rows complete; upper beak moderately deep, forming broad arch with slender lateral processes; lower beak slender, broadly V-shaped; both beaks finely serrate (Fig. 15C). All tadpoles having fully developed mouth parts have 2/3 tooth rows. Little variation is noticeable in coloration. In many specimens the posterior edge of the body is dark brown instead of pale cream-color. Mottling is rather dense on the caudal fins in all specimens; in some individuals pigment is concentrated along the anterior one-third of the lateral groove. In life the body is dark brown with greenish gold flecks ventrally; the caudal musculature is gray. In each of two recently metamorphosed young the snout-vent length is 14.0 mm. Coloration of young in life (KU 87653 from 11 km. N Vista Hermosa, Oaxaca, México): "Dorsum pale tan with dark brown markings. Thighs orange-yellow; labial stripe white; iris bronze" (Duellman, field notes, July 10, 1964.) _Remarks._--Smith (1953:150) named _cyanosticta_ as a subspecies of _Hyla phaeota_. The differences in cranial characters and certain external characters between _phaeota_ and _cyanosticta_ indicate that they are distinct species. Furthermore, a gap of about 350 kilometers exists between the known geographic ranges of the two kinds. _Distribution._--_Smilisca cyanosticta_ inhabits wet forests on the Atlantic slope of southern México and northern Central America from northern Oaxaca and southern Veracruz through northern Chiapas in México and into El Petén and northern Alta Verapaz in Guatemala (Fig. 2). Apparently the range is discontinuous, for in southern México the species is found in cloud forest at elevations of 830 to 900 meters on the northern slopes of the Sierra de Juárez. In the Sierra de Los Tuxtlas in southern Veracruz the species is found in wet forest at elevations of 300 to 1200 meters, but is absent in the intervening lowlands characterized by drier forest. In the west forests of northern Alta Verapaz and El Petén, Guatemala, the species is found at low elevations. _Specimens examined._--78, as follows: MEXICO: =Chiapas=: Monte Libano, MCZ 28271-9; 8 km. N San Fernando, 24 km. NE Tuxtla Gutierrez, UIMNH 41588. =Oaxaca=: 11 km. N Vista Hermosa, KU 84918-20 (skeletons), 87198-212, 87647 (eggs), 87648-52 (tadpoles), 87653 (young), UIMNH 57199-201; 8 km. S Yetla, KU 87213, UMMZ 124838 (8). =Veracruz=: Coyame, UMMZ 111459-60; between Coyame and Tebanco, UMMZ 121198; Dos Amates, UMMZ 121297; between Laguna de Catemaco and Volcán San Martín, UMMZ 121200; Volcán San Martín, UIMNH 35403-4, 35408-12, UMMZ 118163; SE slope Volcán San Martín, UMMZ 121199, 121295 (2), 121296, 121298. GUATEMALA: =Alta Verapaz=: Chinajá, KU 55935-7, 55938 (skeleton). =El= =Petén=: 10 km. NNW Chinajá (Alta Verapaz), KU 55934; Piedras Negras, CNHM 99006-7, 99227, UIMNH 28853, USNM 111139-41, 111143-7; 8 km. S Piedras Negras, CNHM 99008; Semicoch, USNM 35907. [Illustration: FIG. 2. Map showing locality records for _Smilisca cyanosticta_ (triangles) and _Smilisca phaeota_ (circles).] =Smilisca phaeota= (Cope) _Hyla phaeota_ Cope, Proc. Acad. Nat. Sci. Philadelphia, 14 (9):358, 1862 [Holotype.--USNM 4347 from Turbo, Colombia; J. Cassin collector]. Boulenger, Catalogue Batrachia Salientia in British Museum, p. 402, Feb. 1, 1882. Werner, Sitzungsb. Akad. Wiss. München, 27:215, 1897. Günther, Biologia Centrali-Americana: Reptilia and Batrachia, p. 269, Sept. 1901. Nieden, Das Tierreich, Amphibia, Anura I, p. 261, June 1923. Dunn, Occas. Papers Boston Soc. Nat. Hist., 5:413, Oct. 10, 1931. Gaige, Hartweg, and Stuart, Occas. Papers Mus. Zool. Univ. Michigan, 357:4, Oct. 26, 1937. Cooper, Copeia, 2:122, June 30, 1944. Breder, Bull. Amer. Mus. Nat. Hist., 86(6):416, Aug. 26, 1946. Smith and Taylor, Bull. U. S. Natl. Mus., 194:88, June 17, 1948; Univ. Kansas Sci. Bull, 33:364, March 20, 1950. Taylor, Univ. Kansas Sci. Bull., 35(1):837, July 1, 1952. Brattstrom and Howell, Herpetologica, 10:117, Aug. 1, 1954. Goin, Herpetologica, 14:120, July 23, 1958. Cochran, Bull. U. S. Natl. Mus., 220:57, 1961. _Hyla labialis_ Peters, Monats. Konigl. Akad. Wissen. Berlin, p. 463, 1863 [Holotype.--ZMB 4913 from "region of Bogotá," Colombia]; Monats. Konigl. Akad. Wissen. Berlin, p. 618, Oct. 16, 1873. Boulenger, Catalogue Batrachia and Salientia in British Museum, p. 397, Feb. 1, 1882. _Hyla baudini dolomedes_ Barbour, Occas. Papers Mus. Zool. Univ. Michigan, 129:11, Jan. 25, 1923 [Holotype.--MCZ 8539 from Río Esnápe, Sambú Valley, Darién, Panamá; Barbour and Brooks collectors]. Barbour and Loveridge, Bull. Mus. Comp. Zool. Harvard, 69:278, June, 1929. _Hyla phaeota phaeota_, Smith, Herpetologica, 8:152, Jan. 30, 1953. Minton and Smith, Herpetologica, 16:103, June 17, 1960. _Smilisca phaeota_, Starrett, Copeia, 4:303, Dec. 30, 1960. _Diagnosis._--Size large ([M] 65 mm., [F] 78 mm.); skull as long as wide, lacking frontoparietal fontanelle; large supraorbital flanges having straight edges and extending posterolaterally; large squamosal not in contact with maxillary; tarsal fold moderately wide, full length of tarsus; inner metatarsal tubercle moderately large, low, flat, elliptical; hind limbs relatively long, tibia averaging more than 53 per cent of snout-vent length; labial stripe silvery white; lips lacking vertical bars; loreal region pale green; dark brown or black tympanic mark dispersing into brown venated pattern on flanks; posterior surfaces of thighs pale brown, with or without darker flecks or small cream-colored flecks. (Foregoing combination of characters distinguishing _S. phaeota_ from any other species in genus.) Table 2.--Geographic Variation in Size and Proportions in Males of Smilisca phaeota. (Means in Parentheses Below Observed Ranges; Data Based on Ten Specimens From Each Locality.) ================================================================== |Snout-vent |Head width/|Interorbital Locality |length |snout-vent |distance/ | |length |head width -----------------------------+-----------+-----------+------------ Bonanza, Nicaragua | 40.8-47.7 | 34.1-38.0 | 31.0-36.1 | (43.7) | (36.3) | (35.4) -----------------------------+-----------+-----------+------------ Heredia Prov., Costa Rica | 46.3-59.0 | 32.5-36.0 | 30.5-39.6 | (51.7) | (35.0) | (34.7) -----------------------------+-----------+-----------+------------ Puntarenas Prov., Costa Rica | 53.6-64.9 | 32.6-36.1 | 31.0-38.0 | (61.4) | (34.5) | (34.4) -----------------------------+-----------+-----------+------------ Canal Zone, Panamá | 52.4-65.5 | 33.5-37.6 | 31.3-37.2 | (56.5) | (35.6) | (34.7) -----------------------------+-----------+-----------+------------ Río Quesada, Colombia | 52.6-61.0 | 33.1-37.1 | 30.1-33.9 | (56.0) | (35.0) | (32.1) ------------------------------------------------------------------ _Description and Variation._--For the purposes of analyzing geographic variation in size and proportions, measurements were taken on ten adult males from each of five samples throughout the range of the species. Aside from the data summarized in Table 2, the average ratio of tibia length to snout-vent length is noticeably less in Colombian specimens (53.4 per cent, as compared with 54.8 to 57.8 per cent in the other samples) and the ratio of head length to snout-vent length is noticeably less in Costa Rican specimens (33.5 per cent as compared with 34.9 to 35.1 per cent in the other samples). Also, specimens from Heredia Province, Costa Rica, have a relatively smaller tympanum (62.7 to 80.4 [mean 68.4] per cent of the diameter of the eye, as compared with means of 74.0 to 77.9 per cent in the other samples). Two populations are distinctive as regards the size of adult males. Specimens from the northern Caribbean lowlands of Nicaragua (Bonanza, the northernmost locality for the species) are remarkably small. Males having snout-vent lengths of between 40 and 43 mm. were breeding; the largest male found had a snout-vent length of 47.7 mm. The other extreme in size is attained in specimens from the Pacific lowlands of eastern Costa Rica and western Panamá, where most breeding males have snout-vent lengths of more than 55 mm.; the largest male had a snout-vent length of 64.9 mm. The rather striking differences in size among certain samples and the minor differences in proportions among other samples show no geographic trends. Instead, the variations apparently are random among the samples. The data presented here possibly are the results of inadequate sampling, but more likely reflect actual differences in the populations. The dorsal ground color of _Smilisca phaeota_ is pale green to tan; the venter is creamy white. The dorsum is variously marked with dark olive-green or dark brown spots or blotches (Pl. 6C). A dark interorbital bar is usually present. Usually a large dark dorsal mark extends from the occiput to the sacral region, but in many individuals this blotch is replaced by two or three dark marks. The dorsal markings are irregular in shape and do not tend to form transverse bands or longitudinal bars. The hind limbs are marked by dark transverse bands, usually four or five on the thigh, five or six on the shank, and four on the tarsus. Two or three narrow bands are usually present on the proximal part of the fourth toe. The webbing on the feet is brown. The loreal region is pale green, bordered above by a narrow dark brown canthal stripe extending from the nostril to the orbit. The upper lip is silvery white. A broad dark brown or black mark extends posteriorly from the orbit, encompassing the tympanum, to a point above the insertion of the forelimb. The flanks are pale green or pale tan and marked with a fine dark brown or black venation. The anterior surfaces of the thighs usually are pale brown or grayish tan, sometimes having small, indistinct darker flecks. The posterior surfaces of the thighs are similarly colored, but in most specimens small but distinct dark flecks are present; in some specimens small cream-colored spots are also present on the posterior surfaces of the thighs. A distinct, narrow creamy white anal stripe usually is present. A distinct white stripe is present on the outer edge of the tarsus and fifth toe; on the tarsus the white stripe is bordered below by dark brown. A white stripe also is present on the outer edge of the forearm and fourth finger. In breeding males the throat is dark gray. Little geographic variation in color or pattern is evident. Few, if any, specimens from the Pacific lowlands of South America are green in life. (We have seen no living individuals from South America.) Some living individuals from Costa Rica and all those seen alive from Nicaragua have a tint of pale blue on the flanks. In some specimens the dorsal pattern is so faint as to be barely discernible, whereas in most specimens the pattern is bold. The coloration in the living frogs is highly variable due to extreme metachrosis. Individuals of this species are capable of changing the dorsal coloration from green to brown in a short period of time. Both green and brown individuals have been found active at night. Usually those individuals found hiding by day are brown. One individual from Finca La Sumbadora, Panamá (now KU 91914), was kept alive in the laboratory for nearly one month. This individual usually was pale green with tan dorsal markings at night and tan with pale green markings by day. On occasion the pale green dorsal markings were boldly outlined by bright dark green. In living individuals from throughout the range of the species the iris is a bronze color, darkest medially with fine black reticulations. _Natural History._--_Smilisca phaeota_ inhabits humid lowland tropical forest and seldom ascends the foothills to more than 1,000 meters. The rather equable climatic conditions, especially more or less evenly distributed rainfall throughout the year, permit this frog to be active most of the year. Dunn (1931:413) reported males calling on Barro Colorado Island, Panamá, in February and in July, and Breder (1946:416) noted calling individuals in the Chucanaque drainage of Darién, Panamá in January, March, July, August and October and in Costa Rica in April through August inclusively. Calling males were found at Bonanza, Nicaragua in March and in July. At all times of year the usual daytime retreats for these frogs are near water; the frogs have been found in elephant ear plants (_Xanthosoma_) and in bromeliads; occasional individuals have been found sitting on shaded branches of bushes and trees. None has been observed on the ground or beneath ground-cover by day. The length of the breeding season cannot be determined definitely. The earliest date on which eggs have been found is May 23; Gaige, Hartweg, and Stuart (1937:5) reported a gravid female taken at El Recreo, Nicaragua, in September, and we have a gravid female taken at Almirante, Panamá, in March. Males usually call from secluded spots at the edge of water. All calling males that we observed were on the ground within a few centimeters of the water. The males usually are hidden beneath an overhanging leaf or some other cover; they definitely do not sit in the open like _Smilisca baudini_. Most calling males and clasping pairs have been found at the edges of small pools or shallow ditches, although occasional individuals are found at the edges of large ponds or streams. The breeding call consists of one or two moderately short, low-pitched notes (duration 0.33 to 0.42 seconds), repeated at intervals of about 20 seconds to several minutes. Each note is a low, vibrant "wauk," having 100 to 130 pulses per second and a dominant frequency of 330 to 420 cycles per second (Pl. 10C). The eggs are deposited in loose clumps amidst vegetation in the water. Hatchling tadpoles have total lengths of 8.7 to 10.6 mm., and body lengths of 4.1 to 4.5 mm. The external gills are long and filamentous, and the yolk sac is large. The head and caudal musculature are dark brownish black, and the caudal fins are gray. The oral discs are large and roughly circular. The growth and development of the tadpoles are summarized in table 11 and figure 16. A typical tadpole in stage 30 of development (KU 68482 from the Río Chitaría, Cartago Province, Costa Rica) may be described as follows: body length 9.7 mm.; tail length 14.6 mm.; total length 24.3 mm.; body as wide as deep; snout rounded dorsally and laterally; eyes widely separated, directed dorsolaterally; nostril about midway between eye and tip of snout; mouth anteroventral; spiracle sinistral, about midway on length of body and slightly below midline; anal tube dextral; caudal musculature slender, curved upward distally; dorsal fin extending onto body; depth of dorsal fin slightly less than that of ventral fin at mid-length of tail; dorsal part of body pale brown; ventral surfaces transparent with scattered pigment; pale cream-colored, crescent-shaped mark on posterior edge of body; caudal musculature pale creamy tan with scattered pale brown spots; caudal fins transparent with scattered small brown blotches on dorsal and ventral fins; iris pale bronze in life (Fig. 13); mouth small; median part of upper lip bare; rest of mouth bordered by one row of pointed papillae; lateral fold present; tooth-rows 2/3, first upper row longest; second upper row slightly shorter, broadly interrupted medially; three lower rows complete, equal in length, slightly shorter than second upper row; upper beak moderately deep, forming broad arch with slender lateral processes; lower beak slender, broadly V-shaped; both beaks serrate (Fig. 15E). In tadpoles having fully developed mouthparts the tooth-row formula of 2/3 is invariable. The pale crescent-shaped mark on the posterior part of the body curves anterodorsally on the dorsal surface of the body. These marks in dorsal view give the appearance of a pair of short, pale stripes on the posterior part of the body. Most specimens from Costa Rica have the pale coloration like that described above, but some individuals (notable KU 87683 from Guápiles, Costa Rica, KU 87707 from Finca Tepeyac, Nicaragua, and KU 87708 from Bonanza, Nicaragua) have much more pigment. In these specimens the same color pattern obtains as in the pallid individuals, but the pigmentation is dense. This is especially noticeable on the tail. Recently metamorphosed young have snout-vent lengths of 12.7 to 16.7 mm. (average, 14.3 mm. in eleven specimens). Coloration of young in life (KU 68484 from Río Chitaría, Cartago Province, Costa Rica): "Dorsum pale tan; side of head and flanks darker brown, separated from tan dorsum by an indistinct cream stripe. Limbs pale yellow; thighs flecked with brown; shank and tarsus yellowish tan with indistinct brown bars. Soles of feet brown. Belly white; throat dusty cream flecked with silvery white. Upper lip silvery white. Iris bright gold with black flecks. Heels, tarsal and anal stripes white" (Duellman, field notes, May 23, 1961). _Remarks._--Peters (1863:463) named _Hyla labialis_ from the "region of Bogotá, Colombia", but in 1873 regarded his new species as identical with _Hyla phaeota_ Cope, 1862, from Turbo, Colombia. The name _Hyla labialis_ has been used for frogs from the northern Andes in Colombia (see Dunn, 1944:72, and Stebbins and Hendrickson, 1959:522, for discussion of nomenclature). Rivero (1961:131) used the name _Hyla vilsoniana_ Cope, 1899, for the frogs from the northern Andes previously referred to _Hyla labialis_. A review of the nomenclature and taxonomy of these frogs, which superficially resemble _Smilisca_ but are unrelated, is beyond the scope of the present study. _Hyla baudini dolomedes_ Barbour, 1923, is based on a small _Smilisca phaeota_ (MCZ 8539) having a snout-vent length of 45.5 mm. Dunn (1931a:413) placed _dolomedes_ in the synonymy of _Smilisca phaeota_. We have examined the holotype of _dolomedes_ and agree with Dunn's assignment. Smith (1953:150) described _Hyla phaeota cyanosticta_ from Guatemala. Our studies on the external morphology, coloration, and especially the cranial osteology provide evidence that _cyanosticta_ is a species distinct from _phaeota_. _Distribution._--_Smilisca phaeota_ inhabits humid tropical forests from northeastern Nicaragua southward on the Caribbean lowlands to elevations of about 1000 meters and on the Pacific lowlands of Costa Rica, exclusive of the arid regions of Guanacaste, throughout the lowlands of Panamá, exclusive of the savannas of the Pacific lowland and the Azuero Peninsula, and southward on the Pacific slopes of South America through Colombia to west-central Ecuador; also the valleys of the Río Cauca and Río Magdalena in Colombia (Fig. 2). _Specimens examined._--528, as follows: NICARAGUA: =Matagalpa=: Finca Tepeyac, 10 km. N, 9 km. E Matagalpa, KU 85439, 87707 (tadpoles); Matagalpa, MCZ 3546-7, UMMZ 92367; 19 km. N Matagalpa, UMMZ 116495-6. Zelaya: Bonanza, KU 84854-62, 84950-2 (skeletons), 85440-50, 87708-9 (tadpoles); Cukra, AMNH 80618; Río Mico, 16 km. E Recreo, UMMZ 79711 (6), 79712 (4); junction Río Mico and Río Siguia, UMMZ 79713 (10); Río Siguia, 11 km. NW Rama, UMMZ 79714 (14), 79715 (11), 79716 (21), 79717, 79718 (3). COSTA RICA: =Alajuela=: Cinchona, KU 32255, 64286-8; 5 km. S Ciudad Quesada, USC 8077; Laguna Monte Alegre, KU 64289-90; Las Playuelas, 11 km. S Los Chiles, USC 7216; San Carlos, USNM 29961. =Cartago=: Moravia de Turrialba, KU 32212-47, 37133-5, 41093 (skeleton), 64280-1, USC 7243 (3); Peralta, KU 32271-2; Río Chitaría, 3 km. NNE Pavones, KU 64273-9, 68477 (eggs), 68478-83 (tadpoles), 68484 (young); Río Reventazón, MCZ 29196-203, UMMZ 117677 (9); Turrialba, KU 25720-2, 32209-11, 32266-8, 32273-4, 37136-67, 41090-2 (skeletons), 64270-2, MCZ 29221, 29222 (tadpoles), 29269-70, USNM 29934. =Guanacaste=: Tilarán, KU 36805-7; 8 km. NE Tilarán, KU 36803-4. =Heredia=: Barranca del Río Sarapiquí below Isla Bonita, KU 64282-3; Cariblanco, KU 32256-60, 41094 (skeleton), 64284, MCZ 7967; Isla Bonita, KU 32250-4; 4.2 km. W Puerto Viejo, KU 64285, 68485; 7.5 km. W Puerto Viejo, KU 68486; 1 km. S Puerto Viejo, KU 86518. =Limón=: Bambú, USC 7182 (4); Batán, UMMZ 118582; Coén, MCZ 9825; La Lola, KU 32262-4, UF 4029, UMMZ 117678 (3); Los Diamantes, CNHM 101295-8, KU 25723-4, 32265, 64267-9; Pandora, UMMZ 122650 (2), USC 7188 (3), 7190; Puerto Limón, KU 32261; Río Larí at Río Dipari, 21 km. SW Amubre, USC 7177; Río Toro Amarillo, 7 km. W Guápiles, KU 86519, 87683 (tadpoles); Suretka, KU 36808-10, 37168. =Puntarenas=: Agua Buena, KU 36790; 1.6 km. E Buenos Aires, UMMZ 117578; 3 km. NW Buenos Aires, KU 64304; 4 km. N, 15 km. W Dominical, KU 68491-2 (tadpoles); Esparta, MCZ 8029-30, 8032; Golfito, KU 32270; 6 km. E Golfito, KU 84999-500 (skeletons); Gromaco, UMMZ 123677 (4); Palmar, KU 32269; 4 km. ESE Palmar Sur, KU 64305-6; 5.6 km. SE Palmar Sur, KU 68489 (tadpoles); 7.0 km. SE Palmar Sur, KU 68490 (young); 8.5 km. SE Piedras Blancas, KU 64292-303; Quebrada Boruca, 22 km. E Palmar Norte, KU 64291; Rincón, "Camp Seattle," Peninsula de Osa, UMMZ 123676 (3), USC 7254; Río Ferruviosa, 7 km. S Rincón, USC 7235; 1.6 km. WNW Villa Neily, KU 68493 (young), 68494 (tadpoles). =San José=: San Isidro el General, KU 32249, UMMZ 75025; 10 km. N San Isidro el General, MCZ 29099-103; 13 km. WSW San Isidro el General, KU 86517; 15 km. WSW San Isidro el General, KU 68487 (tadpoles), 68488 (young), 68495 (young); 20 km. WSW San Isidro el General, KU 32248. PANAMA: No province: Cano Saddle, USNM 69588; Punta de Pena, USNM 38733; Quipo, AMNH 18925-6. =Bocas del Toro=: Almirante, KU 80080, 91835-6; 1.6 km. W Almirante, KU 91837; 3 km. W Almirante, KU 91824 (skeleton), 91838-43, 91906-7; 11 km. NW Almirante, CNHM 67853-61; 13 km. W Almirante, KU 91825-7 (skeletons), 91844-9; Fish Creek, KU 92329; Isla Popa, KU 91850-1. =Canal Zone=: Barro Colorado Island, CNHM 6007, 13316, 13325, 13331, 13360-2, 13377-8, MCZ 24191-5, UF 7523, UMMZ 63547-60, 64457, 69497 (3); 3.7 km. W Cocoli, KU 67916; Fort Sherman, MCZ 10139; Gatun, MCZ 35644; Junction roads C25B and C16, TNHC 23839; Madden Forest Preserve, TNHC 23837-8. =Coclé=: El Valle, KU 77521-4, 77649 (tadpole), TNHC 23369. =Comarca del Barú=: Progreso, UMMZ 61085-9. Colón: Achiote, KU 77516-20, 77648 (young); Río Candelaria, CNHM 67851-2. =Darién=: Río Esnápe, Sambú Valley, MCZ 8539; Río Sucubti, Chalichiman's Creek, AMNH 40512; Camp Creek, AMNH 40758-9; Camp Creek, Camp Townsend, AMNH 40988. =Panamá=: NW slope Cerro Prominente, KU 80459; Finca La Sumbadora, KU 91914 (skeleton). =Chiriquí=: 2 km. W Concepción, AMNH 68910. COLUMBIA: =Antioquia=: Puerto Berrio, CNHM 30805 (Goin); Turbo, USNM 39899. =Caldas=: Pueblorrica, Santa Cecilia, CNHM 54768-71 (Goin). =Choco=: No specific locality, AMNH 3984-6; Andagoya, BMNH 1915.10.21. 69-70, CNHM 81857 (Goin); Golfo de Urabá, CNHM 63881 (Goin); Peña Lisa, Condoto, BMNH 1913.11.12. 118-125, 1913.11.12. 137-146 (Goin); Pizarro, CNHM 4451-3, 4455-61 (Goin); Río San Juan, Playa del Oro, CNHM 54772 (Goin); Río Quesada, AMNH 13615-77; 37 km. up Río Puné, AMNH 13688; 48 km. up Río Puné, AMNH 13689. =Narino=: Tumaco, Río Rosario, CJG 2310-13 (Goin). =Valle=: Buenaventura, BMNH 1895.11.16.82 (Goin); Raposa, WAT 166, 346-47, 388 (Goin); Río Calima above Córdoba, CJG 2249-57 (Goin). ECUADOR: No province: Bulun, AMNH 10620. =Esmeraldas=: Cachabé, AMNH 10625-8; Río Capayas, CNHM 35712; Río Sapaya, UMMZ 58910 (5); Salidero, AMNH 10623-4; San Javier, AMNH 10618. =Guayas=: Hacienda Balao Chico, UMMZ 123904. =Imbabura=: Pambelar, AMNH 10629, 10631. =Pichincha=: Hacienda Espinosa, 9 km. W Santo Domingo de los Colorados, KU 40220. =Smilisca puma= (Cope), new combination _Hyla puma_ Cope, Proc. Amer. Philos. Soc., 22:183, 1885 [Holotype.--USNM 13735 from Nicaragua; J. F. Moser collector]. Günther, Biologia Centrali-Americana: Reptilia and Batrachia, p. 270, Sept., 1901. Nieden, Das Tierreich, Amphibia, Anura I, p. 251, June, 1923. Cochran, Bull. U. S. Natl. Mus., 220:58, 1961. _Hyla wellmanorum_ Taylor, Univ. Kansas Sci. Bull. 25(1):843, July 1, 1952 [Holotype.--KU 30302 from Batán, Limón, Costa Rica, Edward H. Taylor collector]; Univ. Kansas Sci. Bull., 36(1):626, June 1, 1954. Duellman and Berg, Univ. Kansas Publ. Mus. Nat. Hist., 15:194, Oct. 26, 1962. _Smilisca wellmanorum_, Starrett, Copeia, 4:303, Dec. 30, 1960. _Diagnosis._--Size small ([M] 38.0 mm., [F] 46.0 mm.), differing from other species in the genus by the following combination of characters: skull about as long as broad; frontoparietal fontanelle keyhole-shaped; supraorbital flanges absent; squamosal small, not in contact with maxillary; bony portion of ethmoid terminating at anterior edge of orbit; tarsal fold weak, two-thirds length of tarsus; inner metatarsal tubercle small, low, flat, elliptical; snout rounded in dorsal profile; lips thin and flaring; fingers having only vestige of web; toes one-half webbed; diameter of tympanum about two-thirds that of eye; narrow labial stripe white; pair of dark brown (sometimes interconnected) stripes on tan dorsum; no blue spots on flanks or thighs; vocal sac in breeding males pale brown. (Foregoing combination of characters distinguishing _S. puma_ from other species in genus.) _Description and variation._--Ten breeding males from the vicinity of Puerto Viejo, Heredia Province, Costa Rica, have snout-vent lengths of 32.5 to 37.9 mm. (34.8 mm.). In these specimens, the length of the tibia to the snout-vent length is 0.48 to 0.53 (0.51), and the tympanum/eye ratio is 0.52 to 0.72 (0.65). Seven females have snout-vent lengths of 40.8 to 45.8 mm. (43.9 mm.). No individual has more than a vestige of a web between the second and third and fourth fingers. None has a web between the first and second fingers. Breeding males lack nuptial excrescences on the thumbs. The vocal sac is moderately large and bilobed. In preserved specimens the dorsal ground color varies from yellowish tan to grayish brown. All specimens have dark brown dorsal markings in the form of a pair of dorsal stripes, variously modified (Pl. 7A). In some specimens, such as KU 91716, the stripes are discrete and extend from the postorbital region nearly to the vent. In most specimens the stripes are connected by a transverse mark in the scapular region and in many others also by a transverse mark in the sacral region. In some specimens the stripes are fragmented posteriorly; fragmentation is extreme in KU 30300, in which the dorsal pattern consists of two series of dark longitudinal dashes. The other extreme is a nearly complete fusion of the stripes, as in KU 91714. A dark brown interorbital bar usually extends onto the eyelids, but in some specimens this is reduced to a short V-shaped mark or small spot between the eyes. There is no dark post-tympanic mark, but dark brown pigment forms a venated pattern from the axilla to the mid-flank; the inguinal region is white, finely mottled with dark brown. The dorsal surfaces of the hind limbs are colored like the body and have two or three dark brown transverse marks on the thighs, three to five marks on the shanks, and one or two marks or irregularly arranged dark flecks on the tarsi. The anterior and posterior surfaces of the thighs are pale tan to brown. The webbing of the feet is tan to grayish brown. A narrow white labial stripe, white anal stripe, and narrow white stripes on the tarsi and outer edges of the forelimbs are invariably present. The ventral surfaces are creamy white. In life the dorsum is tan or pale brown with dark brown markings. Some individuals have scattered metallic green flecks on the dorsum. The flanks are mottled dark brown and creamy white. The posterior surfaces of the thighs are dark brown. The vocal sacs are grayish brown, and the iris is a deep bronze color. _Natural History._--_Smilisca puma_ inhabits humid lowland tropical forests having more or less evenly distributed rainfall throughout the year. The equable climatic conditions seemingly permit these frogs to be active throughout most of the year. Taylor (1952:846) found calling males at Batán, Costa Rica, on July 20, 1951. We found the species breeding near Puerto Viejo, Costa Rica, on February 19, June 18, July 13, and July 31. Specimens of calling males from Costa Rica in the collection at the University of Southern California were obtained in February at La Fortuna, on August 22 at Los Diamantes, on August 30 at Jabillos, and on September 5 at La Lola. Gravid females were collected in June, July and August. Males call from shallow water. All breeding congregations of this species that we have found were in a grassy marsh, 7.5 kilometers west of Puerto Viejo, Costa Rica. Tadpoles were found in water-filled depressions in the marsh at night. When first observed, tadpoles were near the surface of the water; they responded to light by quickly taking refuge in the dense grass. No tadpoles were observed by day. The breeding call consists of a low squawk, usually followed by a series of one or more rattling secondary notes (duration of primary notes, 0.06-0.35 seconds; of secondary notes, 0.10 to 0.47 seconds), repeated at intervals of 5 to 55 seconds. The primary notes have 187 to 240 pulses per second and major frequencies of about 740 to 1870 cycles per second (Pl. 11A). Only six tadpoles are available for study. Four of them in stage 34 of development have body lengths of 9.0 to 9.5 mm., tail lengths of 14.0 to 15.0 mm., and total lengths of 23.0 to 24.5 mm. One tadpole in stage 38 and one in stage 40 have total lengths of 31.0 mm. A typical tadpole in stage 34 of development (KU 91807 from 7.5 km. W Puerto Viejo, Heredia Province, Costa Rica) has a body length of 9.5 mm., tail length of 15.0 mm., and total length of 24.5 mm.; body about three-fourths as deep as wide; snout rounded dorsally and laterally; eyes widely separated, directed dorsolaterally; nostril about midway between eye and tip of snout; mouth anteroventral; spiracle sinistral, about two-thirds distance from snout to posterior end of body and slightly below midline; anal tube dextral; caudal musculature slender, barely curved upward distally; dorsal fin extending onto body; at mid-length of tail, depth of caudal musculature equal to that of dorsal fin and ventral fin; body grayish brown, palest ventrally; caudal musculature pale creamy yellow with bold gray reticulations; caudal fins transparent with gray reticulations anteriorly and black flecks posteriorly on both fins (Fig. 14A). Median part of upper lip bare; rest of mouth bordered by two rows of short blunt papillae; lateral fold present; tooth-rows 2/3; upper rows equal in length; second upper row broadly interrupted medially; three lower rows complete, first and second rows equal in length, slightly shorter than upper rows; third lower row noticeably shorter; upper beak shallow, forming broad, continuous arch with slender lateral processes; lower beak slender, broadly V-shaped, both beaks finely serrate (Fig. 15B). All six tadpoles are colored alike, except that in the larger specimens scattered white flecks are present on the ventral surface of the body, and the dark reticulations continue farther posteriorly on the caudal fins than in the smaller tadpoles. In two specimens the third lower tooth-row is only about one-half the length of the other lower rows, and in one specimen the second lower tooth-row is shorter than the first. Coloration of tadpoles in life: "Body olive-brown with silvery green flecks laterally. Caudal musculature olive-brown with greenish tan flecks. Fins brown with greenish gold flecks. Iris deep bronze." (Duellman, field notes, February 19, 1965). One recently metamorphosed young (KU 91808) has a snout-vent length of 12.4 mm. In life this frog had a pale tan dorsum with dark brown markings, yellowish tan posterior surfaces of thighs, grayish brown throat, and bronze iris. _Remarks._--The identity of Cope's _Hyla puma_ has not been known. The name has appeared in various compilations, but no workers have referred any of their specimens to that species. Examination of the holotype (USNM 13735), an adult female, revealed the presence of the following combination of characters: snout-vent length 45.8 mm., snout blunt above and rounded laterally, nostrils close to tip of snout, lips thin and flaring, a vestige of a web on the hands, feet about one-half webbed, tarsal fold weak and extending about two-thirds length of tarsus, dorsal markings consisting of a faded dark interorbital bar and a pair of faded longitudinal brown marks connected by a transverse band in the scapular region. The type agrees well with specimens of _Smilisca wellmanorum_ (Taylor, 1952); the vestigial webbing on the hands and the dorsal coloration are especially significant. Consequently, we consider _Hyla wellmanorum_ Taylor, 1952, to be a synonym of _Hyla puma_ Cope, 1885. Cope gave only "Nicaragua" as the locality for _Hyla puma_. The specimen was part of a collection received at the United States National Museum from Lt. J. F. Moser. Among the species in the collection are _Dentrobates pumilio_, _Phyllomedusa helenae_, _Corythophanes cristatus_, _Pliocercus dimidatus_, _Tretanorhinus nigroluteus_, and others characteristically found on the Caribbean lowlands of Central America. Thus, it seems reasonable to assume that the type specimen of _Hyla puma_ came from the Caribbean lowlands. Though no other Nicaraguan specimens have been found by us, numerous specimens are known from the Caribbean lowlands of Costa Rica. Cochran (1961:58), in her catalogue of type specimens in the United States National Museum, listed _Hyla puma_ Cope, 1885, as a synonym of _Hyla molitor_ Schmidt, 1857. She made no qualifying statements. Schmidt (1858:246), in his descriptions of the species in the year following his publication of the names and Latin diagnoses, stated: "Dorsum uniformly gray, more intensive on back, fading away laterally and on extremities; in every-day-life this blue would be called _Mueller's Blau_. A delicately dotted black line runs on the canthus rostralis from the opening of the nose to the corner of the eye. In the armpits, on the flanks and the thighs two of our three specimens have black marblings." [Free translation] Certainly on the basis of coloration _Hyla puma_ is distinctly different from _Hyla molitor_. _Distribution._--This species lives in the wet, forested regions of the Caribbean lowlands of Costa Rica and presumably southern Nicaragua (Fig. 3). All specimens are from low elevations; the highest known elevation for the occurrence of this frog is 285 meters at Laguna Bonilla. [Illustration: FIG. 3. Map showing locality records for _Smilisca puma_ (triangles) and _Smilisca sila_ (circles).] _Specimens examined._--62, as follows: NICARAGUA: No specific locality, USNM 13735. COSTA RICA: =Alajuela=: Jabillos, 5 km. N Santa Clara, USC 8058 (6); 5 km. W La Fortuna, USC 8078 (2); Río La Fortuna at La Fortuna, USC 7151 (3). =Cartago=: Laguna Bonilla, tunnel camp near Peralta, KU 32171. =Heredia=: Puerto Viejo, KU 86521; 5.9 km. W Puerto Viejo, KU 64307; 7.5 km. W Puerto Viejo, KU 64308-10, 64311 (skeleton), 64312-15, 68635-6 (skeletons), 85001-2 (skeletons), 86520, 87770-1 (skeletons), 91709-16, 91791-2, 91807 (tadpoles), 91808 (young). =Limon=: Batán, KU 30300-2; La Lola, KU 32169, USC 141, 201, 8067; Los Diamantes, KU 32170, UMMZ 118470 (6), USC 212; 2.4 km. E Los Diamantes, USC 8049 (5). =Smilisca sila= new species _Hyla gabbi_, Noble, Proc. Biol. Soc. Washington, 37:66, Feb. 21, 1924. Dunn, Occas. Papers Boston Soc. Nat. Hist., 5:413, Oct. 10, 1931. Schmidt, Smithsonian Misc. Coll., 89(1):6, March 16, 1933. _Hyla sordida_, Dunn, Copeia, 3:166, Nov. 19, 1937. Cooper, Copeia, 2:121, June 30, 1944. Breder, Bull. Amer. Mus. Nat. Hist., 86(8):417, Aug. 26, 1946. _Hyla phaeota_, Breder, Bull. Amer. Mus. Nat. Hist., 86(8): pl. 55, Aug. 26, 1946. _Holotype._--Adult male, KU 91852 from a small stream at the north edge of the village of El Volcán, Chiriquí Province, Panamá, elevation 1280 meters; obtained on Feb. 5, 1965, by William E. Duellman. _Paratypes._--KU 91853-74, collected with the holotype. _Diagnosis._--Size moderate ([M] 45.0 mm., [F] 62.2 mm.); skull wider than long, having large, ovoid frontoparietal fontanelle; supraorbital flanges absent; squamosal small, not contacting maxillary; bony section of ethmoid extending anteriorly between nasals; tarsal fold weak, full length of tarsus; inner metatarsal tubercle low, flat, elliptical; lips thick, rounded, not flaring; fingers one-third webbed; toes three-fourths webbed; diameter of tympanum about one-half that of eye; margin of upper lip faintly marked by interrupted creamy white stripe; dark spots on dorsum; pale flecks on flanks and posterior surfaces of thighs; vocal sacs in breeding males dark brown. (Foregoing combination of characters distinguishing _S. sila_ from any other species in genus.) _Description of holotype._--Snout-vent length 36.6 mm.; tibia length 19.8 mm., 54.1 per cent of snout-vent length; foot length 15.5 mm., 42.3 per cent of snout-vent length; head length 12.7 mm., 34.7 per cent of snout-vent length; head width 13.3 mm., 36.8 per cent of snout-vent length; snout short, in lateral profile truncate, only slightly rounded above, in dorsal profile rounded; canthus rounded; loreal region noticeably concave; lips thick, rounded, not flaring; nostrils not protuberant, directed laterally; internarial distance 3.0 mm.; internarial area flat; top of head flat; interorbital distance 3.5 mm., 26.3 per cent of head width; diameter of eye 4.2 mm., thrice distance (1.4 mm.) from tympanum to eye, and half again distance (2.8 mm.) from orbit to nostril; pupil horizontally ovoid; width of eyelid 2.8 mm., 21.1 per cent of head width; dermal fold from posterior corner of orbit covering upper edge of tympanum to point above insertion of forelimb; diameter of tympanum 2.3 mm., 54.7 per cent of diameter of eye; no axillary membrane; arms moderately robust; weak fold on wrist; faintly scalloped fold along ventrolateral margin of forearm; fingers short, slender; fingers from shortest to longest, 1-2-4-3; vestige of web between first and second fingers; others about two-fifths webbed; discs moderate, diameter of that on third finger about one-third diameter of eye; triangular outer palmar tubercle; elliptical inner palmar tubercle on base of pollex; subarticular tubercles large, conical, none bifid; supernumerary tubercles few, large, conical; brown nuptial excrescence on prepollex; heels overlap by about one-fifth length of shank when hind limbs adpressed; tibiotarsal articulation extending to nostril; tarsal fold weak, extending nearly full length of tarsus; inner metatarsal tubercle elliptical, flat; outer metatarsal tubercle absent; toes moderately long; toes from shortest to longest, 1-2-3-5-4, third and fifth about equal in length; discs about same size as those on fingers; webbing extending to middle of penultimate phalanx on all toes, except only to distal end of antepenultimate phalanx of fourth toe; subarticular tubercles round; supernumerary tubercles large, round, present only on proximal digits. Anal opening directed posteriorly at level of upper edge of thighs; no noticeable anal sheath; flat tubercles ventrolateral to anal opening large; skin of chest, belly, and posterior surfaces of thighs granular; other surfaces smooth; tongue broadly cordiform, shallowly notched posteriorly, and barely free behind; vomerine teeth 4-4, situated on ventral surfaces of separated rounded prominences between posterior margins of small, ovoid inner nares; vocal slits long, each situated along inner margin of ramus; color (in preservative) pinkish tan above with irregular olive-brown markings forming interconnected spots on back; four bars on dorsal surface of each thigh; five bars on shank, and three on tarsus; inguinal region white with black mottling; posterior surfaces of thighs yellowish tan proximally, dark brown distally; margins of lips grayish white with brown markings; ventral surfaces of hands and feet grayish brown; belly and posterior part of throat creamy white; anterior part of throat brown. _Description and variation._--Ten breeding males from Finca La Sumbadora, Panamá, have snout-vent lengths of 40.0 to 44.8 mm. (42.3 mm.). In these specimens the tibia/snout-vent length ratio is 0.50 to 0.57 (0.54), and the tympanum/eye ratio is 0.48 to 0.58 (0.53). There is a geographic gradient in size; specimens from the western part of the range (southern Costa Rica) are smaller than those from the eastern part of the range (eastern Panamá). Five males from the Pacific lowlands of southern Costa Rica have snout-vent lengths of 31.6 to 38.2 mm. (34.7 mm.); ten males from El Volcán, Chiriquí, Panamá, 32.6 to 37.9 mm. (36.4 mm.), and eight males from Barro Colorado Island, Canal Zone, 38.2 to 42.0 mm. (35.6 mm.). These are smaller than the males from Finca La Sumbadora, which is east of the Canal Zone. Ten females from El Volcán have snout-vent lengths of 44.2 to 55.6 mm. (49.2 mm.), as compared 56.1 to 62.2 mm. (58.2 mm.) in three females from Finca La Sumbadora. Large females have scattered small tubercles on the head and back; tubercles occur in males from Costa Rica and in some males from western Panamá. The truncate snout is characteristic of both sexes. The coloration of _Smilisca sila_ consists of a gray, tan, or pale reddish brown dorsal ground color and a creamy white venter. The dorsum is marked by dark brown, olive-brown, or dark reddish brown spots or blotches (Pl. 7B). Usually the blotches are discrete, but in some individuals they are interconnected and form an irregular dark mark on the dorsum. There is no tendency for the blotches to form transverse bars as in _Smilisca sordida_. In one specimen (KU 80467) the blotches are fused and form two wide irregular longitudinal stripes, as in _Smilisca puma_. In some females the dorsal markings are reduced to a few small spots or are nearly absent (KU 92332), whereas in other females the dorsal markings are bold. In one female (KU 91894) the dorsal markings are narrowly bordered by pale blue, and numerous pale blue flecks are present on the pale brown dorsum. In many individuals of both sexes small white flecks are present on the dorsal surfaces. Usually the flanks and posterior surfaces of the thighs have black mottling enclosing pale blue spots and flecks, respectively. The dorsal surfaces of the limbs are marked by dark brown transverse bars; usually three or four bars are present on each forearm, thigh, and shank. The coloration of the flanks and limbs varies geographically. Specimens from southern Costa Rica and western Panamá have distinct bars on the limbs; the posterior surfaces of the thighs have brown reticulations enclosing small blue flecks in specimens from Costa Rica and bolder, black reticulations enclosing large pale blue spots in specimens from western Panamá. In specimens from Costa Rica the flanks are brown with pale blue flecks, whereas in those from Chiriquí, Panamá, the flanks are pale blue with dark brown mottling in the inguinal region. Frogs from El Valle and Cerro la Campana usually have distinct bars on the limbs; the posterior surfaces of the thighs are colored as in frogs from Chiriquí, and the inguinal region is pale blue with coarse brown mottling. Specimens from Barro Colorado Island are marked like those from El Valle and Cerro la Campana, except that on the posterior surfaces of the thighs fine black reticulations enclose many dark blue spots. In specimens from Darién and from Panamá Province east of the Canal Zone (Altos de Pacora, Cerro Jefe, Finca La Sumbadora, and Río Pacora), the markings on the dorsal surfaces of the limbs are indistinct or absent in males, but distinct in some females. Intense brown and black pigment forms fine reticulations delimiting bold blue spots on the flanks; this coloration extends to the axilla in many specimens. Fine black reticulations enclose many dark blue spots on the posterior surfaces of the thighs. In females, the throat is creamy white; in some specimens scattered brown flecks are present on the chin and throat. In breeding males the anterior part of the throat is dark gray or dark brown. The coloration in life is as variable as it is in preservative. In life the holotype had a tan dorsum with dark olive-green irregular markings and small green flecks. The limbs were tan with dark brown transverse bars. The flanks were grayish tan anteriorly; the inguinal region and posterior surfaces of thighs were blue with black mottling. The belly was creamy white, and the throat was brown with creamy yellow flecks. The iris was a dull bronze color. Among the paratypes, some individuals had green flecks, others did not. The inguinal region and posterior surfaces of the thighs were pale blue, pale yellowish green, or grayish tan with black mottling. The blue was most noticeable in females. Colors of a male from Finca La Sumbadora, Panamá, were described as follows: "Dorsum olive-brown; irregular dark brown blotches, pale green flecks, and raised creamy yellow spots on dorsal surfaces; belly creamy white; throat grayish brown; undersides of limbs grayish tan; groin, anterior and posterior surface of thigh, inner surface of shank, anterior edge of tarsus, and proximal parts of third and fourth toes pale blue marbled with dark brown and black; webbing brown; iris pale bronze, finely reticulated with black." (Duellman, field notes, January 28, 1964.) A female (now KU 91894) from Altos de Pacora, Panamá, was described as follows: "An irregular dark brown, green-bordered figure on head and back; dark brown, green-bordered bands on limbs--all on a lighter brown and heavily green-spotted background. These markings are more vivid at night than during the day. Lower sides, from midbody onto front of thighs and rear of thighs onto venter of shanks to heels and thence dorsally onto basal portions of toes heavily blue spotted on a light brown (front of thighs and venter of shanks) to blackish brown background. Venter cream. Iris gray-brown, finely veined with dark brown." (Charles W. Myers, field notes, December 14, 1964.) Note that in the earlier discussion of coloration of preserved specimens, the green spots and borders have changed to pale blue after six months in alcohol. In living individuals from Costa Rica and Panamá west of the Canal Zone, the blue coloration on the flanks and thighs is much less conspicuous than in specimens from eastern Panamá. The color of the iris is variable, even in frogs from one locality. The coloration of the iris in 13 living frogs (now KU 92333-45) from Valle Hornito, Chiriquí, Panamá, was described as follows: "Iris variable--from pale to dark brown; in a few the iris has a golden cast to the brown; in a few others the lower half of the iris is pale gray with the upper half being light brown." (Charles W. Myers, field notes, April 24, 1965). _Natural history._--_Smilisca sila_ inhabits the Pacific slopes of lower Central America where a pronounced dry season occurs. We have records of males calling in December through May and also in August (latter date from El Volcán, Chiriquí, Panamá). The breeding season seems to be correlated with the time of the year when the water is clear and at a low level in the streams where these frogs breed. Males call from the edges of small, shallow streams, from rocks in the streams, or less frequently from vegetation overhanging the streams. Females are most frequently found on the banks of streams, and clasping pairs usually are in shallow pools in streams. One individual was found in a bromeliad about three meters above the ground in the daytime. The breeding call consists of a low squawk, usually followed by a series of one or more rattling secondary notes (duration of primary notes, 0.06 to 0.28 seconds; of secondary notes, 0.14 to 0.48 seconds), repeated at intervals of 4 to 20 seconds. The primary notes have 97 to 120 pulses per second and major frequencies of about 900 to 2220 cycles per second (Pl. 11B). Eggs were obtained artificially in the field; the average length of ten embryos in the neural groove stage is 2.4 mm., and the average diameter of the outer envelope is 4.9 mm. Hatchlings have large, conical oral discs, heavy gills, and a large amount of yolk; their average total length is 6.3 mm. Tadpoles have been found in pools in clear streams; some tadpoles have been observed to cling by their mouths to rocks in the stream; others were found on the bottom where they seek refuge among pebbles or under rocks and leaves. A complete developmental series of tadpoles is not available. Eleven tadpoles in stage 25 of development have body lengths of 8.3 to 10.2 mm. (9.3 mm.), tail lengths of 17.3 to 21.0 mm. (18.8 mm.), and total lengths of 25.9 to 31.0 mm. (28.1 mm.). One tadpole in stage 41 and one in stage 42 have body lengths of 11.5 and 12.5 mm., tail lengths of 27.2 and 29.5 mm., and total lengths of 38.7 and 42.0 mm., respectively. The snout-vent lengths of two specimens in stage 43 and one in stage 45 are 12.7, 13.0, and 13.6 mm., respectively. A typical tadpole in stage 25 of development (KU 80620 from Finca La Sumbadora, Panamá) has a body length of 9.5 mm., tail length of 19.0 mm., and a total length of 28.5 mm.; body only slightly wider than deep, nearly flat dorsally; snout broadly rounded in dorsal view, bluntly rounded in lateral view; eyes widely separated, directed dorsolaterally; nostril slightly closer to eye than to tip of snout; mouth ventral; spiracle sinistral, located about two-thirds distance from snout to posterior edge of body; anal tube dextral; caudal musculature moderately heavy, straight; dorsal fin not extending onto body; fins deepest at about two-fifths length of tail, where depth of caudal musculature about equal to depth of dorsal and depth of ventral fin; musculature extending nearly to tip of tail; body dark grayish brown above and pale grayish tan below with small dark brown spots dorsally and white flecks laterally; caudal musculature pale tan with dark brown flecks over entire surface and dark brown streaks on posterior one-half of ventral fin and on all of dorsal fin (Fig. 14B). Median one-third of upper lip bare; rest of mouth bordered by a single row of conical papillae; lateral fold present; tooth rows 2/3; upper rows cone-shaped, about equal in length, broadly /\-shaped; second upper row narrowly interrupted medially; lower rows complete, about equal in length, but slightly shorter than upper rows; upper beak moderately massive, its inner surface forming a continuous arch with short lateral processes; lower beak broadly \/-shaped; both beaks finely serrate (Fig. 15D). Tadpoles from El Volcán, Chiriquí (KU 91833), are more heavily pigmented than those from Finca La Sombadora; the spots on the tail are larger. In life these tadpoles had dark brownish black bodies with golden and green lichenous flecks; the tail was tan with dark brown markings, and the iris was a grayish bronze color. In life tadpoles from Finca La Sumbadora were olive-tan above and dark gray with pale bluish gray irridescent spots ventrally. The caudal musculature was creamy tan with brown flecks and streaks, and the iris was pale bronze. Metamorphosing young have been found on vegetation at the edge of streams and have been raised in the laboratory. Seven recently metamorphosed young have snout-vent lengths of 13.6 to 15.6 mm. (14.6 mm.). A living juvenile (KU 91913) raised in the laboratory from a tadpole obtained at Finca La Sumbadora had a brown dorsum with darker brown markings, a white spot below the eye, and a narrow white labial stripe. The belly was white; the flanks were brown with white spots, and the posterior surfaces of the thighs were yellowish tan. The iris was a golden bronze color with much black reticulation. _Remarks._--This species has been confused with _Smilisca sordida_; most authors have referred both species to _Hyla (Smilisca) gabbi_. Examination of the types of _Hyla sordida_, _gabbi_, _salvini_, and _nigripes_ revealed that all of the names were referable to a single species (_S. sordida_), and that the small, blunt-snouted species in Panamá and southern Costa Rica probably was without a name. Possibly _Hyla molitor_ Schmidt (1857) is based on the species that we have named _S. sila_, but several discrepancies in his description, plus the unknown provenance of the type, have led us to discount the applicability of that name to the species under consideration. _Distribution._--_Smilisca sila_ ranges along the Pacific slopes and lowlands of southern Costa Rica and Panamá at elevations from sea level to about 1300 meters; in northern South America the species occurs in the Caribbean lowlands and in the valleys of the northward draining rivers of Colombia (Fig. 3). _Specimens examined_, 234, as follows: COSTA RICA: =Puntarenas=: 6 km. E Golfito, KU 91717; Quebrada Boruca, 22 km. E Palmar Norte, KU 64265-6; Río Zapote, 7 km. E Palmar Norte, USC 7100 (2). =San José=: San Isidro el General, KU 28200; 14 km. NW San Isidro el General, USC 7098 (2); 15 km. WSW San Isidro el General, USC 7097. PANAMA: =Canal Zone=: Barro Colorado Island, AMNH 62320-3, CNHM 13324, 13326-8, 13330, 13338, 13359, 13423-5, KU 80460-6, 80619 (young), 80625 (skeleton), UMMZ 63542-6, USC 7051. =Chiriquí=: Boquete, AMNH 69815, UMMZ 58441-5; El Volcán, KU 77413, 91828-31 (skeletons), 91852-74, 91832 (eggs), 91833 (tadpoles); 6 km. S El Volcán, CNHM 60442; 16 km. NNW El Volcán, KU 91879-90; Finca Palosanto, 6 km. WNW El Volcán, KU 77406-12, 77692 (skeleton), 91875-7, 92330-1; Río Colorado, 17 km. NNW El Volcán, KU 91878, 92332; Valle Hornito, 19 km. NE Gualaca, KU 92333-45. =Coclé=: El Valle, AMNH 55440-5 (13), 59607-14, CNHM 48140, 60349-2, 60387-92, 60401-4, 60443, 67842-5, KU 91834 (young), 91902-4, TNHC 23751-2, USNM 140653. =Colón=: Río Candelaria, AMNH 53708-15, CNHM 67826-36. =Darién=: Camp Creek, Camp Townsend, AMNH 40756-7, 40936-9, 40992; Río Chico, AMNH 39784, 40986-7; Río Pita, CNHM 67823-5; Tacarcuna, USNM 141796-802; Three Falls Creek, AMNH 41684, 51788. =Los Santos=: Cerro Hoya, USNM 148213-4; Lajamina, Río Puria, KU 67915. =Panamá=: Altos de Pacora, KU 91894; Cerro Jefe, KU 91895-6; Cerro La Campana, CNHM 67846, KU 91897-900, USNM 139689; Finca La Sumbadora, KU 80467-81, 80620 (tadpoles), 91910 (eggs), 91911-2 (tadpoles), 91913 (young), 91908-9 (skeletons); Río Calobra, USNM 53722, Río Pacora, 9 km. NNE Pacora, KU 91901. =Veraguas=: Cerro Carbunco, USNM 129066; Cerro Tute, CNHM 67837-41; Isla Cebaco, Río Platanal, KU 91891-3. COLOMBIA: =Antioquia=: Urabá, Villa Arteaga, CNHM 63893 (Goin). =Atlantico=: Sabanalarga, Río Causa, AMNH 14506. =Smilisca sordida= (Peters), new combination _Hyla sordida_ Peters, Monatsb. Konigl. Akad. Wissen. Berlin., p. 460, 1863 [Syntypes.--ZMB 3141 (two specimens) from "Veragua," Panamá; J. von Warszewicz collector]. Brocchi, Mission scientifique au Mexique ..., pt. 3, sec. 2, Études sur les batrachiens, p. 42, 1881. Boulenger, Catalogue Batrachia Salientia in British Museum, p. 393, Feb. 1, 1882. Günther, Biologia Centrali-Americana: Reptilia and Batrachia, p. 273, Sept. 1901. Nieden, Das Tierreich, Amphibia, Anura, I, p. 258, June, 1923. _Hyla gabbi_ Cope, Jour. Acad. Nat. Sci. Philadelphia, new ser., 8, pt. 2:103, 1876 [Syntypes.--USNM 30658-9 from near Sipurio, Limón, Costa Rica; William M. Gabb collector]. Brocchi, Mission scientifique au Mexique ..., pt. 3, sec. 2, Études sur les batrachiens, p. 37, 1881. Boulenger, Catalogue Batrachia Salientia in British Museum, p. 372, Feb. 1, 1882. Cope, Bull. U. S. Natl. Mus., 32:32, 1887. Günther, Biologia Centrali-Americana: Reptilia and Batrachia, p. 274, Sept. 1901. Werner, Abhand. Konigl. Akad. Wissen. München., 22:351, 1903. Nieden, Das Tierreich, Amphibia, Anura I, p. 252, June, 1923. Taylor, Univ. Kansas Sci. Bull., 35(1):840, July 1, 1952. Cochran, Bull. U. S. Natl. Mus., 220:54, 1961. _Hyla nigripes_ Cope, Jour. Acad. Nat. Sci. Philadelphia, new ser., 8, pt. 2:104, 1876 [Syntypes.--USNM 30685-6, from Pico Blanco, Costa Rica; William M. Gabb collector]. Brocchi, Mission scientifique au Mexique ..., pt. 3, sec. 2, Études sur les Batrachiens, p. 38, 1881. Boulenger, Catalogue Batrachia Salientia in British Museum, p. 394, Feb. 1, 1882. Cope, Bull. U. S. Natl. Mus., 32:32, 1887. Günther, Biologia Centrali-Americana: Reptilia and Batrachia, p. 278, Sept., 1901. Nieden, Das Tierreich, Amphibia, Anura I, p. 253, June, 1923. James, Copeia, 3:147, Sept. 30, 1944. Taylor, Univ. Kansas Sci. Bull, 35(1):853, July 1, 1952. Cochran, Bull. U. S. Natl. Mus., 220:56, 1961. _Hyla salvini_ Boulenger, Catalogue Batrachia Salientia in British Museum, p. 372, Feb. 1, 1882 [Syntypes.--BMNH 1947.2.24.13-14 from Cartago, Costa Rica; Osbert Salvin collector]. Günther, Biologia Centrali-Americana: Reptilia and Batrachia, pl. 71, Fig. B., Sept., 1901. Werner, Abhand. Zool.-Bot. Gesell. Wien, 46:8, Sept. 30, 1896. _Smilisca gabbi_, Starrett, Copeia, 4:303, Dec. 30, 1960. _Diagnosis._--Size moderate ([M] 45 mm., [F] 64 mm.); skull slightly wider than long, having large and elongate frontoparietal fontanelle; supraorbital flanges absent; squamosal small, not contacting maxillary; bony section of ethmoid terminating just anterior to anterior edge of orbit; tarsal fold weak, full length of tarsus; inner metatarsal tubercle long, low, flat, elliptical; lips thin and flaring; fingers one-half webbed; toes four-fifths webbed; diameter of tympanum about one-half that of eye; no white labial stripe; dorsal dark markings irregular, sometimes forming broad transverse bars; pale flecks on flanks and usually on posterior surfaces of thighs; vocal sacs in breeding males white. (Foregoing combination of characters distinguishing _S. sordida_ from any other species in genus.) _Description and variation._--Ten breeding males from 15 to 20 kilometers west-southwest of San Isidro el General, San José, Costa Rica, have snout-vent lengths of 38.1 to 42.6 mm. (40.5 mm.). In these specimens, the tibia/snout-vent length ratio is 0.50 to 0.54 (0.52), and the tympanum/eye ratio is 0.45 to 0.57 (0.49). Specimens from the Pacific slopes of Costa Rica are larger than those from the Meseta Central and the Caribbean lowlands. Ten males from 6 kilometers east of Golfito, Puntarenas, have snout-vent lengths of 38.4 to 44.6 mm. (41.8 mm.), and five males from Rincón, Peninsula de Osa, have snout-vent lengths of 38.8 to 41.6 mm. (40.3 mm.). Snout-vent lengths of ten males from La Fortuna, Alajuela, are 31.9 to 36.0 mm. (34.4 mm.), of ten males from Pandora, Limón, 33.8 to 37.6 mm. (35.9 mm.), and of ten males from Escazú and Río Jorco on the Meseta Central, 34.3 to 37.6 mm. (36.0 mm.). Eight females from the Río Jorco on the Meseta Central have snout-vent lengths of 48.8 to 53.8 mm. (50.4 mm.), and six females from various localities on the Pacific slopes of Costa Rica have snout-vent lengths of 56.5 to 64.0 mm. (59.8 mm.). The only noticeable differences in proportions between males and females is in the tympanum/eye ratio; for example, this ratio is 0.47 to 0.53 (0.49) and 0.54 to 0.68 (0.61) in ten males and eight females, respectively, from the Meseta Central. The shape of the snout and the associated cranial elements of _S. sordida_ vary geographically and ontogenetically. Specimens from the Caribbean lowlands have blunt snouts in lateral view; those from the Pacific lowlands have longer, more slender snouts that are pointed in lateral view, and those from the Meseta Central are intermediate in snout shape between the two lowland populations (Fig. 4). These differences in shape of the snout are dependent on the nature of the underlying cranial bones, principally the maxillaries and nasals. In specimens from the Caribbean lowlands the nasals are long, wide, and narrowly separated from the ethmoid; the anterior edge is just posterior to the nostril. The maxillary flanges are nearly vertical. In specimens from the Pacific lowlands the nasals are relatively shorter, narrower, and rather widely separated from the ethmoid; the anterior edges of the nasals do not extend so far forward as in specimens from the Caribbean lowlands. The maxillary flanges slant medially. In these cranial characters, specimens from the Meseta Central are intermediate between the two lowland populations. Superimposed on this geographic variation are ontogenetic changes, which are most noticeable in males. In smaller, and presumably younger, specimens the snouts are more pointed than in larger specimens; consequently some small males from the Caribbean lowlands resemble larger males from the Pacific lowlands, since the nasals and maxillaries of the former are not fully ossified. In addition, in small breeding males the ethmoid is only about one-half ossified, a large frontoparietal foramen is present, the anterior arm of the squamosal extends only about one-fourth the distance to the maxillary (two-thirds the distance in larger specimens), and the tegmen tympani are short, as compared with the long, thin elements in larger specimens. [Illustration: FIG. 4. Variation in the shape of the snout in _Smilisca sordida_; left column females, right column males; all from Costa Rica: (A) Camp Seattle, Rincón de Osa, Puntarenas Prov. (UMMZ 123684); (B) Quebrada Agua Buena, 3 km. SW Rincón de Osa, Puntarenas Prov. (USC 7236); (C) Río Oro, 28.5 km. NW Villa Neily, Puntarenas Prov. (KU 91742); (D) Río Jorco, near Desamparados, San José Prov. (KU 91765); (E-F) Bambú, Limón Prov. (USC 7183). ×3.] The dorsal ground-color of _Smilisca sordida_ is gray to pale tan or reddish brown; the venter is white. The dorsum is variously marked with dark gray, dark brown, reddish brown, or olive-green spots or blotches (Pl. 7C). A dark interorbital bar usually is present. The dorsal markings on the body usually consist of a blotch, or two or more spots, on the occiput, in the scapular region, and in the sacral region. In many specimens, especially females, these markings are in the form of broad transverse bars. A female (USC 7164) from Las Cañas, Guanacaste, Costa Rica, has a tan dorsum with many black flecks and round brown spots bordered by darker brown. One female (KU 91763) from the Río Jorco, San José, Costa Rica, has a unicolor tan dorsum. Some individuals have scattered, small white spots on the dorsum; these are most evident in a male (USC 7153) from La Fortuna, Alajuela. White labial stripes and anal stripes are absent in all specimens. The limbs are marked by dark brown transverse bars; these are indistinct in some specimens from the Meseta Central and Caribbean lowlands, whereas they are distinct in all specimens from the Pacific lowlands. Specimens from the Caribbean lowlands have two to six bars on each shank, whereas specimens from the Pacific slopes have four to six bars on each shank, and specimens from the Meseta Central have as many as eight bars on each shank. A narrow, sometimes broken white line is present on the ventrolateral edge of the forearm. The webbing on the hand is tan or pale gray, and the ventral surfaces of the tarsi and the webbing on the feet are dark gray or brown. Breeding males have dark brown nuptial excrescences on the prepollex. The flanks and posterior surfaces of the thighs usually are marked by bluish white and creamy tan flecks, respectively, but vary considerably. In specimens from the Caribbean lowlands a small amount of flecking is present in the inguinal region, and on the posterior surfaces of the thighs flecks are few or absent. In specimens from the Meseta Central, numerous large flecks or small, round spots (pale bluish white in life) are on the posterior half of the flanks; small flecks are on the posterior surfaces of the thighs. Specimens from the Pacific slopes and lowlands of southern Costa Rica (Puntarenas and San José Provinces) have bold mottling of black and bluish white on the flanks and many bluish white flecks on the posterior surfaces of the thighs. The flanks are reticulated from the axilla to the groin in two females (UMMZ 123684 and USC 7236) from Rincón, Peninsula de Osa. In specimens from the Pacific slopes of Guanacaste in northwestern Costa Rica, flecks are present in the inguinal region; indistinct flecks are on the posterior surfaces of the thighs. The throat is immaculate in specimens from the Caribbean lowlands in Limón Province; the throats are dusky laterally in most other specimens except some from the Meseta Central, in which the throats are heavily flecked with black. This variation occurs in males and females. The color and pattern in life are highly variable. A composite description of living individuals (now KU 91718-41) from 6 kilometers east of Golfito, Puntarenas, Costa Rica, illustrates the variability: "Dorsum pale olive-green, fading to tan posteriorly, or tan all over with dark olive-green or dark brown spots on back and bars on limbs. Flanks dark brown with cream, greenish gray, or bluish gray mottling. Posterior surfaces of thighs dark brown with pale blue, pale green, or tan flecks. Iris creamy silver. Throats white with some brown flecks peripherally." (Duellman, Field notes, February 15, 1965.) A male from the Río Jorco, San José, Costa Rica, was dull olive-tan above with olive-green marks; the flanks were brown with pale tan flecks, and the posterior surfaces of the thighs were pale brown with cream-colored flecks. Six females from the same locality were reddish brown above with olive-brown or dark brown markings; one was uniform orange-tan, and another was dull olive-green with darker markings. The color of the iris in living frogs varies from creamy silver to grayish yellow or bronze with a variable amount of black reticulation. _Natural History._--_Smilisca sordida_ is not associated with any one type of vegetation; instead it lives in the vicinity of rocky streams having low gradients. Breeding takes place primarily in the dry season, when the water in the streams is clear and at a low level. Through most of the range of _S. sordida_ showers, or even short heavy rains, occur in the dry season. After such rains the breeding activity is maximal. Breeding congregations have been found from December through April, but a few calling males and gravid females have been taken in June, July, and August. In the rainy season non-breeding individuals are found sitting on bushes near streams at night. Taylor (1952:843) found specimens in bromeliads by day. Males usually call from rocks or gravel bars in, or at the edge of, streams. Some individuals perch in low bushes overhanging the streams, and some sit in shallows in the streams. Clasping pairs have been found on the banks of streams and in shallow water in streams. The breeding call consists of one to six moderately short, rather high-pitched notes (duration 0.18 to 0.45 seconds) repeated at intervals of 12 seconds to several minutes. Each note is a vibrant rattle having 78 to 135 pulses per second and major frequences of about 1200 to 2600 cycles per second (Pl. 11C). The tadpoles live in shallow parts of the streams, where they cling to the surfaces of small rocks and hide beneath leaves and rocks. A complete developmental series of tadpoles is not available; measurements of those stages examined are summarized in Table 12. A typical tadpole in stage 36 of development (KU 68475 from 15 km. WSW of San Isidro el General, Costa Rica) has a body length of 11.7 mm., tail length of 22.8 mm., and a total length of 34.5 mm.; body about three-fourths as deep as wide; snout broadly rounded in dorsal view, sloping and rounded in lateral view; eyes widely separated, directed dorsolaterally; nostril slightly closer to eye than to tip of snout; mouth ventral; spiracle sinistral, about two-thirds distance from snout to posterior end of body and slightly below midline; anal tube dextral; caudal musculature heavy, straight; dorsal fin not extending onto body; fins deepest at about mid-length of tail; there depth of caudal musculature equal to depth of dorsal fin and half again as deep as ventral fin; musculature extending nearly to tip of tail; body reddish brown above and pale grayish brown with white flecks below; caudal musculature pale tan with brown flecks; a series of reddish brown dashes at base of caudal fin separated from others in series and from dashes on other side by creamy white; fins transparent with reddish brown flecks on posterior one-half of ventral fin and on all of dorsal fin (Fig. 14C). Mouth bordered by two rows of short, pointed papillae; lateral fold present; tooth-rows 2/3; upper rows equal in length; second upper row narrowly interrupted medially; three lower rows complete, nearly as long as upper rows, deeply indented medially; upper beak robust, inner surface not forming continuous arch with short lateral processes; lower beak deep, V-shaped; both beaks bearing short serrations (Fig. 15F). Little variation occurs in structure. In some specimens the second upper tooth-row is complete; no individuals were found to have the row broadly interrupted medially. The series of dark dashes on the dorsal edge of the caudal musculature is diagnostic of all stages studied. In life, tadpoles from 15 and 20 kilometers west-southwest of San Isidro el General, Costa Rica, had a tan body, often with an olive-tan tinge; the caudal musculature was tan; the flecks and dashes were dull red or reddish brown. Tadpoles from 6 kilometers east of Golfito, Costa Rica, had bodies with olive-green flecks. The caudal musculature was brown with bluish green flecks; the fins were transparent with reddish brown flecks. The belly was a silvery golden color. Tadpoles from Bajos de Jorco, Costa Rica, had brown bodies with bluish green flecks; the tail and fins had reddish brown flecks and dashes. The iris was a bronze color in specimens from all three localities, as well as in the young mentioned in the following paragraph. Nine recently metamorphosed young were found on vegetation at the edges of streams in April. These specimens have snout-vent lengths of 13.1 to 15.7 mm. (14.9 mm.) and in life were pale greenish tan or olive-tan above and white below. The hands, feet, and thighs were pale yellowish tan. _Remarks._--The foregoing synonymies indicate that confusion has existed in the application of various names, to this species, as well as in use of the names _sordida_ and _gabbi_ to include the species that we describe and name _Smilisca sila_. Correct allocation of the names involved was possible only after studying and comparing the type specimens, for the descriptions given by the various authors are not sufficiently explicit to determine the nature of many essential features. The presence of a rounded snout and a long white throat in males distinguishes _S. sordida_ from _S. sila_, which has a high truncate snout and short dark throat in males. The two syntypes of _Hyla sordida_ Peters, 1863, (ZMB 3141) are males having snout-vent lengths of 36.9 and 37.0 mm. The two syntypes of _Hyla gabbi_ Cope, 1876 (USNM 30658-9), are females having snout-vent lengths of 52.8 and 53.7 mm., respectively. Also included in the collections made by Gabb is eastern Costa Rica are two males (USNM 30685-6), which Cope (1876) named and described as _Hyla nigripes_. These specimens are soft and faded, but are recognizable as the same as _Hyla sordida_ Peters; the syntypes of _Hyla nigripes_ have snout-vent lengths of 37.6 and 37.7 mm. We have examined one of the syntypes of _Hyla salvini_ Boulenger, 1882 (BMNH 1947.2.24.13), a female having a snout-vent length of 54.6 mm. We are convinced that all of these type specimens are representatives of one species, the earliest name for which is _Hyla sordida_ Peters, 1863. The type localities for three of the named species are in Costa Rica--_H. gabbi_ from Sipurio on the Caribbean lowlands, _H. nigripes_ from the Caribbean slopes of Pico Blanco, and _H. salvini_ from Cartago on the Meseta Central. The type locality of _H. sordida_ was given as "Veraguas" by Peters (1863). At that time Veraguas was often considered to be most of western Panamá. Though we have not seen Panamanian specimens other than the types of _S. sordida_ and one specimen from the Pacific lowlands of western Panamá, the species probably occurs on the Caribbean slopes of western Panamá. The species has been taken on the Caribbean lowlands of Costa Rica within a few kilometers of Panamá; collecting on the Caribbean slopes in the provinces of Bocas del Toro and Veraguas should reveal the presence of _Smilisca sordida_ there. _Distribution._--_Smilisca sordida_ is found along the Pacific slopes and lowlands from Guanacaste, Costa Rica, southeastward to extreme western Panamá, to elevations of about 1200 meters on the Meseta Central in Costa Rica, and on the Caribbean slopes and lowlands of Costa Rica and probably adjacent Panamá (Fig. 5). One specimen purportedly comes from "Río Grande, Nicaragua." [Illustration: FIG. 5. Map showing locality records for _Smilisca sordida_.] _Specimens examined._--412, as follows: NICARAGUA: "Río Grande" (? Depto. Zelaya), MCZ 2634. COSTA RICA: =Alajuela=: Between Atena and Salto de San Mateo, USC 6185; 8 km. N Ciudad Quesada, USC 7155 (4); La Fortuna, USC 7153 (20); 3 km. E La Fortuna, USC 7150; San Carlos, USNM 29969; Sarchi, KU 32990-9, 36792-3. =Cartago=: Cartago, BMNH 1947.2.24.13; headwaters of Río Pacuare, USC 119; Instituto Interamericano de Ciéncias Agricolas, Turrialba, KU 37012, USC 420, 437; Río Reventazón, Turrialba, MCZ 29268: 10 km. N Río Reventazón bridge, USC 7073; 5 km. SW Río Reventazón bridge on Paraiso-Orosi road, USC 669; Turrialba, UMMZ 118405, USC 455, USNM 29936-9. =Heredia=: Puerto Viejo, KU 36791. =Guanacaste=: Las Cañas, USC 7164; Santa Cecilia, MCZ 7924-5; Tilarán, USC 7161 (5). =Limón=: Bambú, USC 7171 (2), 7183 (13); La Lola, USC 820 (6), 6083-94, 8064, 8071; Pandora, USC 7188 (7), 7189, 7190 (3), 7191 (5); Pico Blanco, USNM 30685-6; Río Larí, 14-16 km. SW Amubre, USC 7179, 7180 (10); Sipurio, USNM 30658-9; Suretka, KU 36764, 36765 (skeleton), 36766-78. =Puntarenas=: 6 km. N Dominical, KU 91749-50, 91811 (young), 91812 (tadpoles); Esparta, MCZ 8028; 6 km. E Golfito, KU 91718-41, 91809 (young), 91810 (tadpoles), 91816-9 (skeletons), USC 7103 (23); Quebrada Agua Buena, 3 km. SW Rincón de Osa, USC 7236 (6); Quebrada Boruca, 22 km. E Palmar Norte, KU 64264; Rincón de Osa, Camp Seattle, UMMZ 123680-5, S-2792 (skeleton), USC 705 (5), 6023, 7254; Río Barranca, USC 7119 (2); Río Ceiba, 6 km. NW Buenos Aires, KU 91747-8, USC 7112 (7); Río Ciruelitas, 16 km. NW Esparta, USC 7121 (3); Río Claro, 14.2 km. NW Villa Neily, USC 7110 (4); Río Ferruviosa, 7 km. S Rincón de Osa, USC 7235 (4); Río Lagarto at Pan-American Hwy. (Guanacaste Border), USC 7122 (4); Río La Vieja, 30 km. E Palmar Norte, KU 87684 (tadpoles), 91743-6, USC 7083 (2); Río Oro, 28.5 km. NW Villa Neily, KU 91742; Río Volcán, 10 km. W Buenos Aires, USC 7113; Río Zapote, 7 km. E Palmar, USC 7100 (4); 3-5 km. W Palmar, USC 7101 (18); 7 km. SE Palmar, KU 64261-3; 1.2 km. NW Villa Neily, USC 8032; 3 km. NW Villa Neily, USC 7109 (20); 5 km. NW Villa Neily, USC 6176, 8035. =San José=: Bajos de Jorco, KU 91813 (tadpoles); Escazú, KU 34863, 34869-75, USC 813; between Monrovia and La Hondura, ± 0.5 km. N Santa Rosa, USC 302 (2); Paso Ancho, Río Jorco, UMMZ 122649 (6), USC 530 (3); Río Jorco, near Desamparados, KU 91757-65, 91796-7, 91820-3 (skeletons), USC 228, 513, 7117 (7); Río Peje, 10 km. SSE San Isidro el General, USC 7115 (3); Río Tiriví, MCZ 7972; San Isidro el General, CNHM 101096, KU 28201, 32989, UMMZ 72024; 15 km. WSW San Isidro el General, KU 64245-56, 68473 (tadpoles), 68474 (young), 68475 (tadpoles), 86516, 91754-6, 91793-5, USC 7097 (6); 17.1 km. WSW San Isidro el General, USC 6047; 18 km. WSW San Isidro el General, USC 689; 20 km. WSW San Isidro el General, KU 64257-9, 64260 (skeleton), 68468 (young), 68469 (tadpoles), 68470 (young), 68471-2 (tadpoles), 68476 (young), 68633-4 (skeletons), 91751-3; San José, AMNH 7501-4, USC 298; Santa Rosa, Río Virilla, USC 7145. PANAMA: =Chiriquí=: Río Jacu, 5.8 km. ESE Paso Canoas, KU 91905. "Veraguas," ZMB 3141 (2). ANALYSIS OF MORPHOLOGICAL CHARACTERS Osteology In attempting to assay the taxonomic significance of skeletal differences we are faced with a dearth of data on the skeletons of frogs in general and hylids in particular. Recent reviews by Brattstrom (1957) and Hecht (1962, 1963) have been concerned with general salientian classification and phylogeny, principally at the family level. Savage and Carvalho (1953), Griffiths (1959), and Baldauf (1959) used osteological characters in determining the taxonomic status of the families Pseudidae, Brachycephalidae, and Bufonidae, respectively. Carvalho (1954) presented osteological evidence for the generic separation of New World microhylids. Zweifel (1956) and Tihen (1962) used osteological characters at the levels of the species-group and species in their respective studies on _Scaphiopus_ and _Bufo_. Little has been recorded about the skeletons of the hylids. Goin (1961) mentioned dentigerous elements and cranial co-ossification in his synopsis of the genera of hylids. Copland (1957) in his review of the _Hyla_ of Australia, Funkhouser (1957) in her revision of _Phyllomedusa_, and Zweifel (1958) in his review of _Nyctimystes_ did not consider skeletal characters. Some osteological studies on hylids have yielded worthwhile information. Mittleman and List (1953) used osteological characters in defining the genus _Limnaoedus_: Starrett (1960) used cranial characters in combination with jaw musculature in defining the genus _Smilisca_, and Duellman (1964) used cranial characters in delimiting the _Hyla bistincta_ group. Brief descriptions of cranial structure were given for _Phrynohyas_ (Duellman, 1956) and _Ptychohyla_ (Duellman, 1963a); specific and sexual differences in the skulls of _Hyla chaneque_ and _Hyla taeniopus_ were pointed out by Duellman (1965). Stokely and List (1954) described early cranial development in the hylid _Pseudacris triseriata triseriata_. Because our knowledge of the skeleton in hylids is so incomplete, we are not attempting to place _Smilisca_ in the general scheme of hylid phylogeny on the basis of skeletal characters. Instead, our purposes are to describe the skeleton and its ontogenetic development in one member of the genus (_S. baudini_), and to make comparisons that show taxonomic differences in osteological characters among species of _Smilisca_. The study of 68 dried skeletons and 25 cleared and stained preparations, including an ontogenetic series of _S. baudini_, has resulted in an understanding of the progressive development of skeletal elements and a knowledge of interspecific and intraspecific variation in these elements. Furthermore, investigations of the osteology have provided correlations between some cranial characters and certain aspects of external morphology. _Descriptive Osteology of Smilisca baudini_ The following description is based primarily on an adult female (KU 68184): _Skull._--The skull is large, solid, and broader than long; the greatest width is between the sutures of quadratojugal and maxillary on either side of the skull (Pls. 2-3). The maxillaries bear well-developed dorsal flanges, curve gently, join the moderately convex premaxillaries anteriorly and form a slightly truncate snout. The combined premaxillary width is about one-fourth the width of the skull. The premaxillaries are separated medially, and laterally from the maxillaries by sutures. Each premaxillary bears a dorsomedial alary process, which is anteriorly convex and four times as high as the depth of the lateral wing of premaxillary; each premaxillary also has a ventromedial palatine process that projects dorsally from the lingual edge of the premaxillary. The septomaxillaries are closely associated dorsally with the premaxillaries immediately lateral to the prenasal processes. The nasals are large, widest anteriorly and narrowing posteriorly, parallel to maxillaries, and not separated from the ethmoid by cartilage. The nasals bear long, delicate maxillary processes extending nearly to the maxillaries. Anteriorly, the nasals are widely separated by the partially ossified internasal septum, which is in contact with the premaxillaries between the prenasal processes; the anterior points of the nasals lie approximately one-half the distance between the anterior ends of the ethmoid and the premaxillaries. The ethmoid is large and completely ossified; the margins are smooth. The trunate anterior edge lies between the nasals and is in contact with the internasal septum. The frontoparietals are large, smooth-margined, and bear large supraorbital flanges curving posterolaterally at the rear of the orbit. A small, oval foramen involves the posterior part of the ethmoid and anterior portion of frontoparietals; continued ossification in older specimens fills in the foramen, thereby resulting in a solidly roofed cranium. The auditory regions are relatively massive and bear narrow tegmen tympani; the distal ends of the tegmen tympani are medial to the lateral edge of the pterygoids in dorsal view. The squamosals are large; the long anterior arm is separated from the maxillary by a suture. The delicate, spindle-shaped columellae lie ventral to the tegmen tympani and squamosals, are spatulate distally, and have a broad basal attachment to the auditory region. The vomers are moderately large and are in contact anteriorly with the premaxillaries and posteriorly with the ethmoid. Each vomer has two wide serrated flanges laterally. The tooth-bearing parts of the vomers are widely separated and at a slight angle to one another; the vomers terminate medially in two pointed processes on the ethmoid. The palatines are edentate, but bear strong ridges throughout their lengths. They are broadly in contact with the maxillary, are narrow medially, and are attached by pointed processes to the medial part of the ethmoid. The pterygoids are large, attached to the maxillaries immediately anterior and medial to the squamosal-maxillary connection, bear well-developed pedicles, which are broadly attached to the proötic, and a wide wing is in contact posteriorly with the distal two-thirds of the quadrate. The angular makes up most of the lower jaw, bears a broad articular surface posteriorly, and has a small coronoid process on the lingual edge; anteriorly the angular is separated from the dentary and mentomecklian by Meckel's cartilage. The dentary lies external to the angular and extends from the mentomecklian to approximately the mid-length of the angular. The mentomecklians are ossified, but separated by cartilage medially. _Hyoid._--The hyoid plate is curved, thin, and mostly cartilaginous, but calcined posteriorly (Fig. 6). The anterior cornua are slender, cartilaginous, and curve anteromedially from the hyoid plate and thence laterally and posteriorly, to attach to the posterior surface of the proötics. The lateral cornua are broad, flat, cartilaginous lateral extensions from the bases of the anterior cornua. The posterior cornua are bony, except distally. [Illustration: FIG. 6. Ventral view of hyoid apparatus of an adult male _Smilisca baudini_ showing areas of muscle attachment: _Gen. L._, attachment of geniohyoideus lateralis; _Gen. M._, attachment of geniohyoideus medialis; _Hyo._, attachment of hyoglossus; _Omo._, attachment of omohyoideus; _Pet._, petrohyoideus; _St._, attachment of sternohyoideus. KU 64220, ×5.] _Vertebral Column._--The atlas lacks transverse processes and a neural crest, whereas transverse processes are present on the other seven presacral vertebrae, and knoblike neural crests are present on the second, third, and fourth vertebrae; a faint neural ridge is visible on the fifth vertebra. The transverse processes are directed laterally on the second and sixth vertebrae, ventrolaterally on the third, posterolaterally on the fourth and fifth, and anterolaterally on the seventh and eighth. The processes are slightly expanded on the fourth, and more so on the fifth, vertebra. The sacral diapophyses are expanded and have a border of calcified cartilage laterally. There are two sacral condyles. The slender coccyx has a thin dorsal ridge on the anterior three-fourths of its length. _Pectoral Girdle._--The omosternum is large, ovoid, and cartilaginous; the sternum is a thin cartilaginous sheet deeply notched posteriorly and is not differentiated into episternal and xiphisternal elements. The coracoids are robust, twice as stout as the clavicles. The epicoracoidal cartilages overlap in the usual arciferal manner, except that they are fused anteriorly between the slender clavicles. The clavicles are strongly arched. The clavicle, coracoid, and scapula on each side form a bony articulation at the glenoid fossa. A bifurcation of the ventral end of the scapula results in a large glenoid foramen. The scapula is flat and expanded dorsally; the suprascapula is broad, flat, and calcified in large adults. In young specimens no distinct ossification of the cleithrum or ossification of endochondral centers are evident. _Arm and Hand._--The humerus is equally well-developed in both sexes and has a prominent lateral crest. The radius and ulna are completely fused. A bony prepollex is present in both sexes. The metacarpals are about equal in length. The phalangeal formula is 2-2-3-3; the terminal phalanges are claw-shaped. _Pelvic Girdle._--The ilia are long, slender, and slightly curved. A thin ridge projects laterally from the dorsal edge of the posterior one-half of each ilium. The ilial prominence is large and knoblike when viewed from above. The anterior edge of the ilial prominence is at the level of the anterior edge of the acetabular border. The dorsal acetabular expansion is small. The pubis is slender, and the ischium is elevated and robust. _Leg and Foot._--The slightly curved femur has a distinct crest proximally on the posterior surface. The nearly straight tibio-fibula is slightly longer than the femur. The tibial and fibial elements are completely fused but have a distinct cleft between them. A small foramen exists at the mid-length of the tibio-fibula. The fibulare (calcaneum) is much more robust than the tibiale (astragalus). The prehallux is large and flat. The metatarsals of the third, fourth, and fifth digits are equal in length; the metatarsal of the second is somewhat shorter, and that of the first is much shorter. The phalangeal formula is 2-2-3-4-3; the terminal phalanges are claw-shaped. _Developmental Cranial Morphology of Smilisca baudini_ The following description of development of the skull of _Smilisca baudini_ is based on the examination of 12 cleared and stained specimens. In table 3 the cranial bones are listed in the left hand column in the approximate order of their appearance in the young frogs. Across the top of the table selected specimens designated by developmental stage or snout-vent length are listed. It should be noted that although each individual, from left to right, has an increasing number of ossified bones, the correlation with increasing size is imperfect; the precise ages of the individuals are unknown. The first bones to appear are the septomaxillaries, frontoparietals, part of the exoccipital, and the parasphenoid in developmental stage 40. The frontoparietals are represented by two slender ossifications dorsomedial to the orbits; the septomaxillaries are present as small ossifications anterior to the nasal capsules (Pl. 1A). The parasphenoid is present as a faint median ossification, and the exoccipital shows some ossification. Table 3.--The Order of Occurrence of Cranial Ossifications in the Skull of Smilisca baudini. Where Numbers Are Divided by a Slash Mark, the Left and Right Symbols Correspond to the Left and Right Sides of the Skull, Respectively. =====================+=====+=====+=====+=====+=====+=====+==== Bone |Stage|Stage|12.6 |13.9 |32.0 |27.0 |20.1 | 40 | 44 | mm. | mm. | mm. | mm. | mm. ---------------------+-----+-----+-----+-----+-----+-----+---- Frontoparietal | X | X | X | X | X | X | X Parasphenoid | X | X | X | X | X | X | X Septomaxillaries | X | X | X | X | X | X | X Exoccipitals | X | X | X | X | X | X | X Squamosals | -- | X | X | X | X | X | X Premaxillaries | -- | X | X | X | X | X | X Maxillaries | -- | X | X | X | X | X | X Nasals | -- | -- | X | X | X | X | X Pterygoids | -- | -- | X | X | X | X | X Vomers | -- | -- | -- | X | X | X | X Palatines | -- | -- | -- | X | X | X | X Quadratojugals | -- | -- | -- | X | X | X | X Ethmoid | -- | -- | -- | -- | X | X | X Columellas | -- | -- | -- | -- | X | X | X Supraorbital Flanges | -- | -- | -- | -- | -- | X | X Proötics | -- | -- | -- | -- | -- | -- | X Vomerine Teeth | -- | -- | 1/1 | 4/3 | 5/5 | 3/3 | 5/4 Maxillary Teeth | -- | 0/7 | 3/5 | 6/5 |30/31|30/26|37/36 Premaxillary Teeth | -- | 2/4 | 3/3 | 5/5 | 7/6 | 8/6 | 8/7 ---------------------+-----+-----+-----+-----+-----+-----+---- The dentigerous bones are among the most rapidly developed, although not the first to appear. They are present in developmental stage 44 before metamorphosis is completed. The maxillaries bear a few teeth anteriorly and are ossified posteriorly to a point one-third of the distance from the anterior to the posterior edge of the orbit. Ossification lengthens the posterior termini of the maxillaries to the posterior edge of the orbit. In front of the anterior margin of the orbit, bone is proliferated dorsal to the main axes of the maxillaries and forms moderate dorsal maxillary flanges. The premaxillaries appear simultaneously with the maxillaries. Initially they are widely separated medially from each other, and laterally from the developing maxillaries; each bears two or three teeth, large dorsally blunt alary processes, and small palatine processes. The median and lateral edges of the prenasal processes lengthen heterochronously, causing the median edges to be longest and to lie slightly dorsal to the level of the septomaxillaries. After the maxillaries and premaxillaries develop, the vomers appear as small horizontal ossifications anterior to the parasphenoid. Ossification begins in the lateral flanges, then in the prevomerine processes, and lastly in the posterior dentigerous parts of the bones; the prevomerine processes are the last parts of the vomers to ossify completely. Initially the frontoparietals are present as thin rods of ossification dorsomedial to the orbits; the frontoparietals extend from the anterior to the posterior end of the orbit by developmental stage 44. The anterior ends of the bones remain thin and pointed; ossification progresses medially from the midpoint of the length of the orbit and posteriorly to the level of the exoccipital; a median center of ossification joins the frontoparietals posteriorly, thereby forming the posterior border of the frontoparietal fontanelle. The supraorbital flanges of the frontoparietals do not appear until all other cranial bones are ossified, or nearly so. The most rapid ossification begins laterally at the posterior edge of the orbit and decreases anteriorly over the posterior half of the orbit. This differential rate of proliferation of bone results in the pattern of development of the supraorbital flanges shown in figure 7. The nasals appear as thin slivers of bone half way between the anterior ends of the frontoparietals and the end of the snout. As ossification proceeds the nasals assume a triangular shape in dorsal view. The anterior ends are pointed; the lateral margins are parallel to the maxillaries. The posteromedial points do not reach the lateral margins of the ethmoid, and the maxillary processes extend about three-fourths the distance from the bodies of the nasals to the maxillaries. Following the union of the frontoparietals posteriorly, the nasals widen anteriorly and are narrower at the midpoints of their long axes than anteriorly or posteriorly. With further ossification the maxillary processes extend to the maxillaries and form complete bony anterior margins to the orbits; the mid-parts of the nasals widen (Pl. 1B). [Illustration: FIG. 7. Developmental sequence of the frontoparietal fontanelle and associated bony elements in _Smilisca baudird_: (A) KU 60026, ×5; (B) KU 85438, ×4; (C) KU 26328, ×3; (D) KU 68184, ×2.3.] The parasphenoid is the first of the palatal bones to appear. At metamorphosis the bone is well developed; the anterior tip is situated just in front of the anterior edge of the orbit, and posteriorly the lateral processes extend laterally beyond the ossified parts of the auditory region. The pterygoids do not appear until metamorphosis, when ossification is evident in only the mid-parts of the posterolateral arms. Ossification follows in the mid-parts of the anterolateral arms and occurs last in the pterygoid pedicles. The palatines do not appear until all three arms of the pterygoids are at least partly ossified. Ossification proceeds rapidly from the maxillaries medially to the unossified ethmoid, which is the last of the cranial bones to appear. Initially it is extremely shallow; dorsally it is widely separated from the nasals, and ventrally the posterior margin meets the anterior point of the parasphenoid. In dorsal view, ossification proceeds anteriorly between the nasals and posteriorly, ventral to the frontoparietals; ventrally, ossification proceeds posteriorly dorsal to the parasphenoid. The ventral arms of the squamosal and the supraoccipital region of the exoccipital are the first occipital bones to appear. Ossification follows in the regions of the semicircular canals and occipital condyles. The dorsal end of the ventral arm of the squamosal and the posterior arm of the squamosal ossify as a unit at the same time the quadratojugal appears. Shortly thereafter the anterior arm of the squamosal ossifies, the distal part of the columella appears, and the anterior and lateral parts of the auditory region ossify. The angular and dentary of the lower jaw appear concurrently with the dentigerous bones. Initially, the angular is short and broad; the articular surface is absent, and the anterior end is slightly overlapped by the dentary. The mentomecklians do not ossify until approximately the same time that the quadratojugal appears in the upper jaw. _Comparative Osteology_ The genus _Smilisca_ is characterized by the following combination of cranial osteological characters: (1) A large amount of bone is involved in the skull and a minimal amount of cartilage and/or secondarily ossified cartilage; co-ossification is absent. (2) The skulls are uniformly broad with angular lateral margins, and truncate anteriorly. (3) An internasal septum and quadratojugals are present. (4) A well-developed squamosal minimally extends one-fourth the distance from the dorsal end of the quadrate to the maxillary, and maximally is separated from the maxillary by a suture. (5) The ethmoid is large; the distance between the anterior end of the ethmoid and the anterior edge of the premaxillary varies between 15 and 20 per cent of the total length of the skull. On the basis of cranial osteology two species-groups can be recognized within the genus _Smilisca_. The _sordida_ group, comprising _S. sordida_ and _puma_, is characterized by a broad skull in which the lateral margins of the maxillaries are relatively straight anterior to the orbit. The moderate-sized nasals are rounded anteriorly, and bear relatively short, sometimes blunt, maxillary processes. The long axes of the nasals are not parallel to the maxillaries. The ethmoid is proportionately small in the _sordida_ group. The bony part of the ethmoid terminates near the anterior edge of the orbits and does not extend anteriorly between the nasals; the entire anterior margin of the ethmoid is separated from the nasals by cartilage. The squamosals are generally small. They are narrow in dorsal view, and minimally extend one-fourth the distance from the dorsal end of the quadrate to the maxillary, and maximally, two-thirds the distance. The tegmen tympani are relatively small (Fig. 8). [Illustration: FIG. 8. Dorsal views of the skulls of the species of _Smilisca_: (A) _S. baudini_ (KU 68184); (B) _S. puma_ (KU 68636); (C) _S. phaeota_ (KU 41090); (D) _S. sila_ (KU 80625); (E) _S. cyanosticta_ (KU 55938), and (F) _S. sordida_ (KU 36765). ×1.5.] In contrast to the tendency for reduction of cranial parts in the _sordida_ group, the _baudini_ group, constituted by _S. cyanosticta_, _phaeota_, and _baudini_, is characterized by more ossification of the cranial elements. The skull is broad; the lateral margins are less angular and are gently curved, rather than straight as in the _sordida_ group. The nasals tend to be larger with the long axes parallel to the maxillary. Anteriorly the nasals are pointed, and posteriorly they bear long, delicate palatine processes extending to the maxillary. The ethmoid is fully ossified, extends anteriorly between the nasals, and laterally is separated by a suture from the nasals if the latter are fully ossified. The squamosals are large, and wide in dorsal view. They minimally extend one-fourth the distance from the dorsal end of the quadrate to the maxillary, and maximally are sutured to the maxillary. The tegmen tympani are massive. _Smilisca sila_ is intermediate between the two species-groups described. The skull is broad; the lateral margins are gently curved, and have a pronounced angularity just anterior to the palatines which results in a broad, truncate snout. The nasals are moderate in size; because of the anterior angularity of the lateral margins, the long axes of the nasals lie parallel to the maxillary. The nasals are only slightly pointed anteriorly, and posteriorly they bear short, blunt palatine processes and medial processes in contact with the lateral corners of the ethmoid. The ethmoid is fully ossified, but does not extend anteriorly between the nasals. The squamosals are moderate in size and extend one-fourth the distance from the dorsal end of the quadrate to the maxillary. The tegmen tympani are relatively large, but proportionately short. The cranial characters utilized in the analysis of species groups (general shape, nature of the nasals, ethmoid, squamosals, and tegmen tympani), together with other characters, such as the relative height and shape of the prenasal processes, the extent of the internasal septum, and the nature of the vomers, frontoparietals, maxillaries and pterygoids are useful in distinguishing the various species (Table 4, Fig. 8), as well as in establishing relationships within the species-groups. Within the _sordida_ group, _S. sordida_ and _S. puma_ can be distinguished by the following characters: The bony part of the ethmoid terminates posterior to the anterior edge of the orbit and is thus widely separated from the nasals by cartilage in _S. puma_. In _S. sordida_ the bony part of the ethmoid always terminates at a level equal to, or slightly in front of the anterior edge of the orbit; therefore, less cartilage exists between the ethmoid and nasals in _S. sordida_ than in _S. puma_. The width of the premaxillary comprises about 30 per cent of the width of the skull in _S. sordida_ and 20 per cent in _S. puma_. The proportion of the length of the skull anterior to the bony part of the ethmoid in _S. sordida_ is approximately 21 per cent, as compared with about 29 per cent in _S. puma_. The prenasal processes are convex in _S. sordida_ and straight in _S. puma_. The marked ontogenetic variation in _S. sordida_ is considered in more detail in the account of that species, but it is pertinent to the present discussion to note that with respect to some features of the skull some young breeding specimens of _S. sordida_ are intermediate in appearance between large females of _S. sordida_ and adults of _S. puma_. In some breeding males (usually the smaller individuals) of _S. sordida_ the bony part of the ethmoid terminates at the anterior edge of the orbit and is widely separated from the nasals by cartilage. In small individuals _S. sordida_, especially in males, and in adults of _S. puma_ the tegmen tympani are relatively short, whereas in adult females of _S. sordida_ these elements are long and slender. In the smaller specimens of _S. sordida_ and in _S. puma_ the squamosal is small; it extends only about one-fourth of the distance to the maxillary in the smaller _S. sordida_ and about one-half the distance in _S. puma_. The more massive squamosal in large adult females of _S. sordida_ extends at least two-thirds of the distance to the maxillary. Table 4.--Comparative Cranial Osteology of Smilisca. ===============+==============================+======================= Character | _S. baudini_ | _S. cyanosticta_ ---------------+------------------------------+----------------------- | | Alary Processes| Four times as high as | Three times as high | lateral wing of premaxillary;| as lateral wing of | anteriorly | premaxillary; | convex. | anteriorly | | convex. | | Nasals | Long, wide anteriorly, | Long, widest | narrowing posteriorly; | posteriorly; | attached to ethmoid. | attached to | | ethmoid. | | | | | | Ethmoid | Long; entirely ossified; | Long, entirely | smooth margins. | ossified; | | smooth margins. | | Frontoparietal | Small, ovid fontanelle | Large fontanelle, two | present or absent; | and one-half times as | long, pointed postorbital | long as wide; narrow | processes curving | supraorbital flanges | along posterior | with irregular margins. | border of orbit. | | | Squamosal | Large: anterior arm | Large; anterior arm | in contact with maxillary. | in contact with | | maxillary. ---------------+------------------------------+------------------------ TABLE 4 (Continued) ===============+=============================+========================= Character | _S. phaeota_ | _S. puma_ ---------------+-----------------------------+------------------------- | | Alary Processes| Two and one-half | Two times as high as | times as high as lateral | lateral wing of | wing of premaxillary; | premaxillary; | anteriorly convex. | straight. | | | | Nasals | Long, widest anteriorly | Short, narrow, not | and posteriorly, | attached to ethmoid. | bearing posteromedial | | process; not attached | | to ethmoid. | | | | | Ethmoid | Long, entirely ossified; | Short, about two-thirds | smooth margins. | ossified; irregular | | margins. | | Frontoparietal | Fontanelle absent; | Keyhole-shaped fontanelle; | large supraorbital | smooth margins; | flanges having | flanges absent. | straight edges and extending| | posterolaterally. | | | | | Squamosal | Large; anterior arm | Small; anterior arm | extending 1/2-2/3 way | extending 1/2 way to | to maxillary. | maxillary. ---------------+-----------------------------+-------------------------- TABLE 4 (Continued) ===============+===========================+============================ Character | _S. sila_ | _S. sordida_ ---------------+---------------------------+---------------------------- | | Alary Processes| One and one-half | Two and one-half | times as high as lateral | times as high as lateral | wing of premaxillary; | wing of premaxillary; | straight. | slightly convex | | anteriorly. | | Nasals | Short, wide, bearing | Moderately long narrowest | small posteromedial | anteriorly and | processes; not attached | posteriorly; not attached | to ethmoid. | to ethmoid. | | | | | | Ethmoid | Moderately long; entirely | Short; one-half to entirely | ossified; smooth | ossified; irregular | margins. | margins. | | Frontoparietal | Large, ovoid fontanelle; | Large, elongate fontanelle; | smooth margins; | smooth margins; | flanges absent. | flanges absent. | | | | | | | | Squamosal | Moderately large; anterior| Moderately small; anterior | arm extending | arm extending | 1/4 way to maxillary. | 1/4-2/3 way to maxillary. ---------------+---------------------------+---------------------------- Within the _baudini_ group, the skull of _S. cyanosticta_ is the most generalized of the three species; the cranial characters are intermediate between _S. phaeota_ and _S. baudini_. The lateral margins of the skull in _S. cyanosticta_ are gently curved, and have an angularity anterior to the palatine-maxillary suture; the anterior margins are less angular in _S. phaeota_, which has a broader snout. Posteriorly in _S. baudini_ the margins are slightly curved medially, and the greatest width of the skull is between the quadratojugal-maxillary sutures on either side of the skull. The frontoparietals of _S. cyanosticta_ bear slightly irregular lateral margins and a large fontanelle. There is a tendency for obliteration of the fontanelle with increasing age in both _S. baudini_ and _S. cyanosticta_; the lateral margins of the frontoparietals bear large supraorbital flanges in both of these species. In _S. phaeota_ the flanges are most prominent; they extend posterolaterally with straight margins along two-thirds of the length of the orbit and terminate in rather blunt points. The broad interorbital flanges result in a relatively broad external interorbital distance. In _S. baudini_ the flanges are curved posterolaterally around the orbit and terminate in sharp, thin points. The tegmen tympani of all three species are massive. In _S. cyanosticta_ the proötics slope posteriorly, whereas they slope anteriorly in _S. baudini_ and _S. phaeota_. The skulls of _S. cyanosticta_ and _S. baudini_ are alike in certain respects. The squamosals of both species are large and connected to the maxillary by a bony connection; the squamosals of _S. phaeota_ are large, but extend only two-thirds of the distance from the dorsal end of the quadrate to the maxillary. In _S. baudini_ and _S. cyanosticta_ the nasals are separated throughout their lengths from the ethmoid, whereas the nasals of _S. phaeota_ are separated from the ethmoid by cartilage. The latter separation is due to an incomplete ossification of the nasals in _S. phaeota_. The bony part of each nasal is constricted in the middle of the long axis of the bone, and the nasals are widest anteriorly; posteriorly each nasal bears a medial process, which is narrowly separated from the lateral edge of the ethmoid. Table 5.--Variation in the Number of Teeth in the Species of Smilisca. (All Are Males; N = Number of Jaws, or Twice the Number of Individuals; Means Are Given in Parentheses After the Observed Ranges.) =================+====+==============+==============+=========== Species | N | Maxillary | Premaxillary | Vomerine -----------------+----+--------------+--------------+----------- _S. baudini_ | 20 | 49-65 (56.0) | 9-16 (13.6) | 5-9 (7.2) _S. cyanosticta_ | 8 | 50-64 (57.9) | 10-12 (10.8) | 4-11 (7.1) _S. phaeota_ | 20 | 50-68 (58.1) | 10-15 (12.1) | 5-9 (7.3) _S. puma_ | 6 | 60-67 (63.6) | 11-13 (12.0) | 4-7 (5.3) _S. sila_ | 8 | 48-60 (52.9) | 10-14 (11.3) | 5-7 (5.7) _S. sordida_ | 12 | 39-55 (44.2) | 7-11 (9.3) | 4-6 (5.2) -----------------+----+--------------+--------------+----------- The teeth of all species of _Smilisca_ are spatulate and bifid. The numbers of maxillary, premaxillary, and vomerine teeth are summarized in Table 5. Smaller and presumably younger specimens of all species of _Smilisca_ have fewer teeth than do larger specimens of the same species. This correlation between size and number of teeth does not exist as an interspecific trend within the genus; for example, the smallest species in the genus, _S. puma_, has the highest number of maxillary teeth. In small specimens of a given species wide gaps are present between the maxillary teeth posteriorly; in large specimens the gaps are filled by teeth, beginning anteriorly and progressing posteriorly, until the maxillary dentition is continuous. Musculature No extensive study of the muscular system was undertaken, but certain muscles know to be of taxonomic importance were studied. _Jaw Musculature._--Starrett (1960) pointed out the unique jaw musculature in _Smilisca_. In this genus M. depressor mandibulae consists of two parts, one arising from the dorsal fascia and one from the posterior arm of the squamosal. Two muscles arise from the anterior arm of the squamosal and insert on the lateral face of the mandible. Of these muscles, M. adductor mandibulae posterior subexternus lies medial to the mandibular branch of the trigeminal nerve; the other, M. adductor mandibulae externus superficialis, lies lateral to the same nerve (Fig. 9). In most other hylids the latter muscle is absent. No significant variation in the position of the muscles was noted in the various species of _Smilisca_, though M. adductor mandibulae originate somewhat more anteriorly in _S. baudini_ and _S. cyanosticta_ than in the other members of the genus, all of which have a shorter anterior arm of the squamosal that does not reach the maxillary. The two separate parts of M. depressor mandibulae are not so widely separated in members of the _sordida_ group as in the _baudini_ group. [Illustration: FIG. 9. Lateral view of the left jaw of _Smilisca baudini_; _A. M. E. S._, adductor mandibulae externus superficialis; _A. M. P. S._, adductor mandibulae posterior subexternus; _Col._, columella; _D. M._ depressor mandibulae; _M. B. T. N._, mandibular branch trigeminal nerve; _Sq._, squamosal. KU 64214, ×5.] [Illustration: FIG. 10. Ventral view of throat musculature in an adult male _Smilisca baudini_ (Superficial musculature on left, deep musculature on right); _A. C._ anterior cornua of hyoid; _Gen. L._, geniohyoideus lateralis; _Gen. M._, geniohyoideus medialis; _Hyo._, hyoglossus; _Omo._, omosternum; _Pet._, petrohyoideus; _S._, submentalis; _Sm._, submaxillaris; _St._, sternohyoideus; _V. S._, vocal sac. KU 64220, × 2.5.] _Throat Musculature._--The frogs that comprise the genus _Smilisca_ are characterized by paired subgular vocal sacs, essentially the same as those in _Triprion_ (Duellman and Klaas, 1964). The following description is based on _Smilisca baudini_ (Fig. 10). M. submentalis lies in the anterior angle of the lower jaw, is thick, and consists of transverse fibers extending between the dentaries. M. submaxillaris is thin and arises from the whole of the inner surface of the lower jaw, except for the anterior angle occupied by M. submentalis. Anteriorly M. submaxillaris is broadly attached by fascia to M. hyoglossus and M. geniohyoideus, which lie dorsal to M. submaxillaris. Medially this attachment continues posteriorly for about one-half the length of the hyoglossus. Posteriorly M. submaxillaris is folded and attached to M. sternoradialis of the pectoral girdle. The vocal sacs are formed by a pair of posterolateral evaginations of M. submaxillaris; a broad connection between the pouches allows free passage of air between the pouches. The deeper throat musculature is essentially the same as that described for _Phrynohyas spilomma_ by Duellman (1956), except for slight differences in the place of attachment on the hyoid. Skin _Structure_ The skin of _Smilisca_ is typical of that of most hylids in organization and structure. _Smilisca sila_ is distinguished from other members of the genus by the presence of small wartlike protrusions and peculiar white, pustular spots on the dorsum. The wartlike structures are composed of three or four epidermal cells, which protrude from the surface of the epidermis; the structures are covered by a slightly thickened layer of keratin. The white pustules are slightly elevated above the surrounding skin. Internally they consist of aggregations of swollen, granular, pigment-cells (perhaps lipophores) lying between the epidermis and the melanophores. _Biochemical Variations_ Dried skins of all species of _Smilisca_ were sent to José M. Cei, Instituto Nacional de Cuyo, Mendoza, Argentina, for biochemical screening by means of the chromatographic techniques described by Erspamer and Cei (1963). The species in the _baudini_ group have detectable amounts of penta-hydroxi-trypatamine, whereas only a trace is present in the other species. Furthermore, species in the _baudini_ group differ from _S. sila_ and the _sordida_ group in lacking, or having only a trace of, tryptophan-containing polypeptides. These superficial biochemical tests support the arrangement of species as ascertained by conventional taxonomic characters. External Morphological Characters The features of external morphology that were studied in connection with the taxonomy of the genus _Smilisca_ are discussed below. _Size and Proportions_ The frogs of the genus _Smilisca___ are medium to large tree frogs. The three species comprising the _baudini_ group (_S. baudini_, _cyanosticta_, and _phaeota_) are notably larger than _S. puma_, _sila_, and _sordida_ (Table 6). The largest specimen that we examined is a female of _S. baudini_ having a snout-vent length of 90 mm. _Smilisca puma_ is the smallest species; the largest male has a snout-vent length of 38 mm. and the largest female, 46 mm. Table 6.--Comparison of Sizes and Certain Proportions of the Species of Smilisca. (Means in Parentheses Below Observed Ranges; Data for Males Only.) ================+====+===========+=============+===========+ | | Snout-vent|Tibia length/| Tympanum/ | Species | N | length | snout-vent | eye | ----------------+----+-----------+-------------+-----------+ | | | | | _S. baudini_ |140 | 47.3-75.9 | 42.1-53.6 | 56.1-94.4 | | | (58.7) | (47.8) | (73.5) | | | | | | _S. cyanosticta_| 40 | 44.6-56.8 | 51.9-59.7 | 62.7-88.4 | | | (50.7) | (56.0) | (71.4) | | | | | | _S. phaeota_ | 50 | 40.8-65.5 | 50.9-60.2 | 62.7-85.5 | | | (53.9) | (55.5) | (76.6) | | | | | | _S. puma_ | 20 | 31.9-38.1 | 48.2-53.1 | 52.1-72.2 | | | (34.7) | (51.3) | (64.9) | | | | | | _S. sila_ | 33 | 31.6-44.8 | 49.7-58.1 | 47.6-58.3 | | | (37.7) | (54.8) | (53.2) | | | | | | _S. sordida_ | 55 | 31.9-44.6 | 50.5-57.1 | 46.5-57.1 | | | (37.9) | (53.4) | (49.1) | ----------------+----+-----------+-------------+-----------+ No outstanding differences in proportions exist between species, although certain proportions are sufficiently different in some species to warrant mention. _Smilisca baudini_ is a more squat and stocky frog than other members of the genus; this is reflected in the somewhat shorter hind legs (Table 6). The size of the tympanum relative to that of the eye is highly variable within samples of a given species. Even so, noticeable differences in the tympanum/eye ratio are apparent. Members of the _baudini_ group have the largest tympani, whereas _S. sila_ and _sordida_ have the smallest, and _S. puma_ is intermediate (Table 6). _Shape of Snout_ Although all members of the genus have rather truncate snouts, subtle differences exist among the species (Pl. 12). _Smilisca sila_ has the shortest snout; that of _S. baudini_ is only slightly longer. The snouts of _S. cyanosticta_ and _puma_ are nearly square in lateral profile, whereas those of _S. phaeota_ and _sordida_ are slightly inclined. The shape of the snout is relatively uniform within each species and displays no noticeable sexual dimorphism, except in _S. sordida_, in which there are sexual differences and geographic variation (see p. 324). _Hands and Feet_ The characters of the hands and feet are among the most taxonomically important external features in _Smilisca_. Consistent differences exist in relative lengths of the digits, size of subarticular tubercles, size and number of supernumerary tubercles, size and shape of the inner metatarsal tubercle, and amount of webbing (Pls. 4 and 5). In the _baudini_ group the series of species (_baudini-phaeota-cyanosticta_) show a progressive increase in amount of webbing in the hand and a decrease in number, and corresponding increase in size, of supernumerary tubercles. The amount of webbing in the feet of _S. baudini_ and _phaeota_ is about the same, but the webbing is slightly more extensive in _S. cyanosticta_. _Smilisca puma_ is unique in the genus in lacking webbing in the hand; furthermore, this species is distinctive in having many large subarticular tubercles on the hand and a relatively small inner metatarsal tubercle. The two stream-inhabitants, _S. sila_ and _sordida_, have shorter and stouter fingers than the other species. The webbing is most extensive in both the hands and feet of these species, which also are distinctive in having many small supernumerary tubercles on the feet. _Ontogenetic Changes_ Minor ontogenetic changes in structure involve the shape of the snout, relative size of the eye, development of the tympanum, and amount of webbing in the hand. In recently metamorphosed young the snout is more rounded than in adults; the canthus and loreal concavity are not evident. Usually the tympanum is not differentiated in recently metamorphosed young, and the eye is proportionately large. The webbing in the feet is completely developed at metamorphosis, but young individuals have noticeably less webbing in the hand than do adults of the same species. Coloration Some of the most distinctive characters of the species of _Smilisca_ are color and pattern of the living frogs. Although many chromatic features are lost or subdued in preserved specimens, the patterns usually persist. _Metachrosis_ Change in color, well known in frogs, is common in hylids, especially in species having green dorsal surfaces (_Phyllomedusa_ is a notable exception). The non-green _Smilisca_ (_puma_, _sila_, and _sordida_) changes color, but this mostly is a change in intensity of color. In these species the markings usually are most distinct at night; frequently by day the frogs become pallid. The most striking examples of metachrosis in _Smilisca_ are found in the _baudini_ group, in which the dorsal ground-color changes from green to tan; correlated with the change in ground-color may be a corresponding change in the dorsal markings, but the dorsal markings may change to the opposite color. Chromosomes Chromosomes of all six species of _Smilisca_ were studied by means of the propriono-orcein squash technique described by Duellman and Cole (1965). Karyotype analysis was attempted for several species by means of intraperitoneal injections of colchicine, which affected the mitotic cells as desired, but the testes examined contained too few mitotic cells to allow accurate determination of karyotypes. Haploid (_n_) chromosome numbers were determined from cells in diakinesis, metaphase I, and metaphase II of meiosis. Diploid (2_n_) chromosome numbers were determined from cells in late prophase and metaphase of mitosis. Chromosome counts from as few as 23 meiotic cells of _S. phaeota_ and as many as 80 cells of _S. sordida_ reveal a constant haploid (_n_) number of 12; counts of chromosomes in one to five mitotic cells in all species, except _S. sila_, reveal that the diploid (2_n_) number is 24. NATURAL HISTORY Breeding Like most hylid frogs _Smilisca_ is most readily collected and observed when individuals congregate for breeding. _Time of Breeding_ _Smilisca_ breeds primarily in quiet water and reaches its height of breeding activity at times of plentiful rainfall,--usually from May through October. Through most of its range _Smilisca baudini_ breeds in those months, but in some places where abundant rain falls in other seasons, the species breeds at those times. For example, in southern El Petén and northern Alta Verapaz, Guatemala, _Smilisca baudini_ has been found breeding in February and March. The other pond-breeding species (_S. cyanosticta_, _phaeota_, and _puma_) live in regions lacking a prolonged dry season, and possibly they breed throughout the year, but breeding activity seems to be greatest in the rainiest months. The two stream-breeding species (_S. sila_ and _sordida_) breed in the dry season when the streams are low and clear, principally in December through April. At high elevations the species sometimes breed in the rainy season; also, individuals sometimes breed in the short dry season (summer canicula) in July and August. At several localities species have been found breeding at different times of the year: _S. baudini_ in March and July at Chinajá, Guatemala; _S. phaeota_ in April and August at Palmar Sur, Costa Rica; _S. puma_ in February and July at Puerto Viejo, Costa Rica; and _S. sila_ in February, April, and August at El Volcan, Panamá. These observations indicate only that the population breeds at more than one time in the year, but do not provide any evidence on the breeding cycles of the individual frogs. This is one important aspect of the natural history of _Smilisca_ for which we lack data. _Breeding Sites_ All members of the genus _Smilisca_ presumably deposit their eggs in water. _Smilisca baudini_ usually breeds in temporary rain pools; often these are nothing more than shallow, muddy puddles. In other instances the sites are extensive ditches or large flooded areas (Pl. 8, Fig. 1). This species is an opportunistic breeder, and males gather at any of a wide variety of suitable breeding sites that are formed by torrential rains in the early part of the rainy season. _Smilisca baudini_ nearly always breeds in open pools having bare earthen edges. Frequently congregations of _S. baudini_ are found at such small pools, but are absent from nearby large ponds surrounded by vegetation. Little is known of the breeding habits of _S. cyanosticta_, which inhabits humid forests on foothills and lowlands. Apparently its breeding sites are not unlike those of _S. phaeota_, which usually are pools surrounded by vegetation (Pl. 8, Fig. 2), although sometimes males of _S. cyanosticta_ call from open muddy puddles. In uplands, where standing water is uncommon, this species breeds in quiet pools in streams. _Smilisca puma_ breeds in grass-choked ponds and marshes, where the males call from bases of dense clumps of grass in the water (Pl. 9, Fig. 1). _Smilisca sila_ and _S. sordida_ differ noticeably from other species in the genus by breeding exclusively in streams, where males usually call from rocks or gravel bars in or at the edges of streams (Pl. 9, Fig. 2); sometimes individuals perch on bushes overhanging streams. In the streams, or parts of streams, utilized by these frogs the water is clear, shallow, and has a slow gradient; occasional males have been found calling along cascading mountain streams. Breeding choruses composed of ten or more species of frogs are not uncommon in Middle America, but _Smilisca_ usually breeds alone or with one or two other species and at the most five others. This tendency towards solitary breeding possibly is the result of selection of breeding sites that are unsuitable to many other species of frogs. Nevertheless, many other species of frogs have been found at the breeding sites with the various species of _Smilisca_; these breeding associates (Table 7) are most numerous for _S. baudini_, which has a broad geographic range, including a variety of habitats. _Breeding Behavior_ _Calling sites._--All species of _Smilisca_ usually call from the ground, including rocks and gravel bars; some individuals sit in shallow water near the edge of the pool or stream. Sometimes males of _S. baudini_, _sila_, and _sordida_ call from low bushes or trees near the breeding site. One _S. baudini_ was observed calling while it was floating on the surface of a pond. _Smilisca cyanosticta_, _phaeota_, and _puma_ call from secluded places at the edge of the water or in the water, whereas _S. baudini_, _sila_ and _sordida_ call from open situations. Table 7.--Breeding Associates of the Various Species of Smilisca. ==============================+========+============+========+=====+=====+======== Associate |_S. |_S. |_S. |_S. |_S. |_S. |baudini_|cyanosticta_|phaeota_|puma_|sila_|sordida_ ------------------------------+--------+------------+--------+-----+-----+-------- _Rhinophrynus dorsalis_ | X | - | - | - | - | - _Leptodactylus bolivianus_ | - | - | X | - | - | - _Leptodactylus labialis_ | X | - | X | - | - | - _Leptodactylus melanonotus_ | X | - | X | X | X | - _Leptodactylus occidentalis_ | X | - | - | - | - | - _Leptodactylus quadrivittatus_| - | - | X | - | - | - _Leptodactylus pentadactylus_ | - | - | X | X | - | X _Engystomops pustulosus_ | X | - | X | - | - | - _Bufo canaliferus_ | X | - | - | - | - | - _Bufo cavifrons_ | - | X | - | - | - | - _Bufo coccifer_ | X | - | - | - | - | - _Bufo coniferus_ | - | - | X | - | - | - _Bufo cristatus_ | - | X | - | - | - | - _Bufo gemmifer_ | X | - | - | - | - | - _Bufo haematiticus_ | - | - | X | - | X | X _Bufo kellogi_ | X | - | - | - | - | - _Bufo luetkeni_ | X | - | - | - | - | - _Bufo marinus_ | X | - | X | X | X | X _Bufo marmoreus_ | X | - | - | - | - | - _Bufo mazatlanensis_ | X | - | - | - | - | - _Bufo melanochloris_ | - | - | X | - | X | X _Bufo perplexus_ | X | - | - | - | - | - _Bufo typhonius_ | - | - | X | - | X | - _Atelopus varius_ | - | - | - | - | X | X _Diaglena reticulata_ | X | - | - | - | - | - _Diaglena spatulata_ | X | - | - | - | - | - ------------------------------+--------+------------+--------+-----+-----+-------- Table 7.--_Continued_ ==============================+========+============+========+=====+=====+======== Associate |_S. |_S. |_S. |_S. |_S. |_S. |baudini_|cyanosticta_|phaeota_|puma_|sila_|sordida_ ------------------------------+--------+------------+--------+-----+-----+-------- _Hyla boulengeri_ | - | - | X | - | - | - _Hyla colymba_ | - | - | - | - | X | - _Hyla ebraccata_ | X | - | X | - | - | - _Hyla elaeochroa_ | - | - | X | X | - | - _Hyla eximia_ | X | - | - | - | - | - _Hyla legleri_ | - | - | - | - | - | X _Hyla microcephala_ | X | - | X | - | - | - _Hyla phlebodes_ | - | - | X | X | - | - _Hyla picta_ | X | - | - | - | - | - _Hyla robertmertensi_ | X | - | - | - | - | - _Hyla rosenbergi_ | - | - | X | - | - | - _Hyla rufioculis_ | - | - | - | - | - | X _Hyla smithi_ | X | - | - | - | - | - _Hyla staufferi_ | X | - | - | - | - | - _Hyla walkeri_ | X | - | - | - | - | - _Phrynohyas inflata_ | X | - | - | - | - | - _Phrynohyas spilomma_ | X | - | - | - | - | - _Phrynohyas venulosa_ | X | - | - | - | - | - _Phyllomedusa callidryas_ | X | - | X | - | - | - _Phyllomedusa dacnicolor_ | X | - | - | - | - | - _Phyllomedusa moreleti_ | X | X | - | - | - | - _Pternohyla fodiens_ | X | - | - | - | - | - _Smilisca baudini_ | X | X | - | - | - | - _Smilisca cyanosticta_ | X | X | - | - | - | - _Smilisca phaeota_ | - | - | X | - | - | - _Smilisca puma_ | - | - | - | X | - | - ------------------------------+--------+------------+--------+-----+-----+-------- Table 7.--_Concluded_ ==============================+========+============+========+=====+=====+======== Associate |_S. |_S. |_S. |_S. |_S. |_S. |baudini_|cyanosticta_|phaeota_|puma_|sila_|sordida_ ------------------------------+--------+------------+--------+-----+-----+-------- _Smilisca sila_ | - | - | - | - | X | X _Smilisca sordida_ | - | - | X | - | X | X _Triprion petasatus_ | X | - | - | - | - | - _Cochranella fleischmanni_ | - | - | - | - | X | X _Centrolene prosoblepon_ | - | - | - | - | X | - _Gastrophryne elegans_ | X | - | - | - | - | - _Gastrophryne olivacea_ | X | - | - | - | - | - _Gastrophryne usta_ | X | - | - | - | - | - _Hypopachus alboventer_ | X | - | - | - | - | - _Hypopachus caprimimus_ | X | - | - | - | - | - _Hypopachus inguinalis_ | X | - | - | - | - | - _Hypopachus maculatus_ | X | - | - | - | - | - _Hypopachus oxyrrhinus_ | X | - | - | - | - | - _Hypopachus variolosus_ | X | - | - | - | - | - _Rana palmipes_ | X | - | X | X | - | - _Rana pipiens_ | X | - | - | - | - | - _Rana warschewitschi_ | - | - | X | - | X | X ------------------------------+--------+------------+--------+-----+-----+-------- _Chorus structure._--Limited observations on some of the species of _Smilisca_ show a definite organization of the calling behavior of individuals. _Smilisca baudini_ and _S. phaeota_ call in duets. This is especially noticeable in _S. baudini_, in which the members of a duet often call from sites separated by only a few centimeters. The call of _S. baudini_ consists of a series of like notes (see description of call in following section); the duration of each note is about equal to the interval between notes. Normally one individual utters one note, pauses, and utters a single note again, or series of two or three notes. If there is no response, the first individual often waits several seconds or even several minutes and then repeats the call. The second individual usually responds after the first or second note of the sequence. The notes of the second individual usually are spaced so that they are emitted in the intervals between the notes of the first individual. This can be shown diagrammatically by having the figure "1" represent notes of the first individual and figure "2," the notes of the second; an empty interval is represented by "0": 1-0-1-2-1-2-1-2-1-2-1-2 Usually a chorus is initiated by one duet and is quickly picked up by other individuals also calling in duets. A numerical representation of a chorus of eight frogs would approximate the following organization: 1-0-1-2-1-2-1-2-1-2-1-2-1-2 3-0-3-4-3-4-3-4-3-4-3-4-3 5-6-5-6-5-6-5-6-5-6-5-6 7-8-7-8-7-8-7-8-7-8-7-8 After the first one or two duets are initiated, the second individuals in the following duets usually call immediately after their respective partners have given the first notes. The other noteworthy aspect about the organization is that the entire chorus usually stops abruptly. Normally the first duet stops calling shortly before the others, but this is not invariable. Often one duet or one individual will emit several notes after the rest of the frogs have become silent. An interval of several minutes sometimes elapses before the chorus begins again. Successive choruses apparently are initiated by the same duet. Responses can be initiated artificially by imitating the call, and sometimes any loud noise will start a chorus. Similar duets have been observed in _S. phaeota_. In this species the intervals are often much longer than the notes, and if two males are calling in close proximity, their calls can be mistaken for those of one individual. _Smilisca phaeota_ does not congregate in large numbers; usually only two males call from one restricted site. _Smilisca sila_ has a call consisting of a primary note followed by one or more secondary notes. Males often call in duets, but not necessarily so. In a duet, the first male usually utters only primary notes until the second individual responds; then each individual produces a rapid series of secondary notes. _Smilisca puma_ also produces primary and secondary notes. Although individuals sometimes call alone, duets, trios, or quartets were more common. The chorus is initiated by one individual uttering primary notes until joined by the second, third, and fourth frogs. In one quartet in a marsh 7.5 kilometers west of Puerto Viejo, Costa Rica, on February 19, 1965, the same individual initiated four consecutive choruses. Each time the second member of the chorus was the same; the third and fourth frogs joined the chorus nearly simultaneously. Individuals of _S. sordida_ are usually irregularly situated along a stream. No duets or other combinations of individuals are apparent in the chorus structure, but once an individual calls, a frog nearby calls almost immediately; then a frog near the second individual calls, and so on. The resulting series of calls gives the impression that the sound is moving along the stream as successive individuals join the chorus and the first callers become quiet. It is not known if the same individual initiates successive choruses or if the order of calling is the same in subsequent choruses. These limited observations on chorus structure in _Smilisca_ show the presence of behavioral organization. The methods of establishing the organization and the significance of the call-order in breeding have yet to be discovered. Calling males of _S. baudini_ are often close together; some individuals have been observed almost touching one another, but no indication of territoriality or aggressive behavior has been witnessed. The more distant spacing of the stream-breeding species _S. sila_ and _S. sordida_ may be a function of calling-territories, but no direct evidence is available to substantiate this supposition. _Sex recognition and amplexus._--Observations on _Smilisca baudini_ indicate that the calls of males attract females. At Tehuantepec, Oaxaca, México, a female was first observed about two meters away from a male calling at the edge of a rain pool; in a series of short hops she progressed directly towards the male, although vegetation obscured him until she was less than a meter away. When she approached to within about 20 centimeters of the male, he took notice of her, moved to her, and clasped her. At Chinajá, Alta Verapaz, Guatemala, a female swam directly across a pool about three meters wide to a calling male. Her line of movement took her within a few centimeters of a silent male, to whom she paid no attention. She stopped just in front of the calling male, which immediately clasped her. At a large muddy pond 4 kilometers west-northwest of Esparta, Puntarenas, Costa Rica, a female was observed swimming toward a small submerged tree; a male was calling from a branch about one meter above the water. The female climbed to a branch about 20 centimeters below the male, which upon seeing her there immediately jumped down and clasped her. These few observations of _S. baudini_ show that in this species females are capable of locating calling males by means of phono-orientation; visual reception on the part of females seems to be secondary. Contrariwise, males apparently become aware of the proximity of females by seeing them; once a male sees a female he usually tries to clasp her. Possibly the males receive stimuli by means of chemo-reception, but in each observed instance the male obviously looked at the female. Amplexus is axillary in all members of the genus. Normally amplexing males hunch their backs and press their chins to the females' backs. Clasping pairs are usually found at the edge of the water, but sometimes amplexus takes place in trees or bushes. _Egg deposition._--Oviposition has been observed only in _Smilisca baudini_. On the night of June 28, 1961, at Chinajá, Alta Verapaz, Guatemala, a clasping pair was observed at the edge of a shallow rain pool. After sitting for several minutes in shallow water, the female (with male on her back) swam part way across the pool and grasped an emergent stick with one hand. The female's body was nearly level with the surface of the water, and her hind legs were outstretched as deposition commenced; eggs were extruded rapidly. After a few seconds the female moved slowly to another twig a few centimeters away and deposited more eggs. This process was repeated until the female was spent. The spawn resulted in a surface film covering roughly one square meter. It is doubtful if this type of egg deposition occurs in any other species in the genus, especially those that lay their eggs in streams. _Breeding Call_ The breeding calls of the six species of _Smilisca_ are alike in their explosive nature. Calls are emitted quickly with a short burst of air filling the vocal sac, which immediately deflates. Phonetically the calls can be described as a single "wonk" or series of such notes in _S. baudini_ and _S. cyanosticta_, a low growl in _S. phaeota_, a relatively high pitched rattle in _S. sordida_, and a low squawk usually followed by one or more rattling secondary notes in _S. puma_ and _S. sila_. Quantitatively, the calls of the six species differ in number of notes, duration of notes, and in pitch (Table 8, Pls. 10 and 11). Although no measurements were taken on the intensity of the calls, we observed in the field that each of the species has a loud voice. The call of _S. baudini_ seems to carry farther than any of the others. Table 8.--Comparison of Breeding Calls in Smilisca. (Observed Range Given in Parentheses Below Mean. In Species Having Primary and Secondary Notes, Only the Primary Notes Are Analyzed Here.) ==============+====+=======+===========+=========+=========+=======================+ | | Notes | | | Funda- | Major | Species | | per | Duration | Pulses | mental | frequencies (cps) | | N | call | of note | per |frequency+-----------+-----------+ | | group | (seconds) | second | (cps) | Lower | Upper | --------------+----+-------+-----------+---------+---------+-----------+-----------+ _S. | 20 | 8.0 | 0.11 | 174.7 | 166.2 | 351 | 2507 | baudini_ | | (2-15)|(0.09-0.13)|(140-195)|(135-190)| (175-495) |(2400-2725)| | | | | | | | | _S. | 10 | 1.2 | 0.38 | 147.0 | 145.1 | 841 | 1894 | cyanosticta_| | (1-2) |(0.25-0.45)|(110-180)|(135-160)| (480-975) |(1600-2100)| | | | | | | | | _S. phaeota_ | 10 | 1.6 | 0.31 | 116.0 | 143.0 | 372 | -- | | | (1-2) |(0.10-0.45)|(100-130)|(110-165)| (330-495) | -- | | | | | | | | | _S. puma_ | 28 | 3.7 | 0.13 | 208.2 | 145.6 | 743 | 1868 | | | (2-10)|(0.06-0.35)|(187-240)|(125-200)| (495-980) |(1456-2240)| | | | | | | | | _S. sila_ | 15 | 2.4 | 0.16 | 108.5 | 103.0 | 899 | 2218 | | | (1-6) |(0.06-0.28)| (97-120)| (90-115)| (665-1180)|(1980-2700)| | | | | | | | | _S. sordida_ | 19 | 1.7 | 0.29 | 104.7 | 123.1 | 1216 | 2694 | | | (1-6) |(0.18-0.45)| (78-135)| (90-140)|(1150-1540)|(2340-2990)| --------------+----+-------+-----------+---------+---------+-----------+-----------+ _Call rate._--The rate at which call-groups are produced varies from one every few seconds to one in several minutes. In _S. baudini_, _cyanosticta_, _phaeota_, and _sordida_, call-groups are produced as frequently as every 12 seconds, but usually more time elapses between call groups. In _S. sordida_, five or more minutes sometimes elapse between call-groups. The interval is somewhat less in _S. phaeota_. Calls are repeated at much shorter intervals in _S. puma_ (5-55 seconds) and _S. sila_ (4-20 seconds). _Notes per call-group._--Except for _S. puma_ and _S. sila_, the series of notes produced in any given call of a species of _Smilisca_ is essentially the same; there is no differentiation into primary and secondary notes. _Smilisca cyanosticta_ and _S. phaeota_ emit only one or two relatively long notes per call-group, whereas _S. baudini_ and _S. sordida_ produce as many as 15 and 6 notes, respectively. Males of _S. puma_ and _S. sila_ often produce only the primary note; sometimes this is done several times before the secondary notes are produced. For example, one _S. puma_ (KU 91711; tape No. 379) produced the following number of notes in consecutive call-groups: 1, 1, 1, 1, 2, 2, 3, 1, 4; secondary notes are present in only four of the nine call-groups. A typical series of consecutive call-groups in _S. sila_ (KU 91852; Tape No. 385) has 1, 1, 1, 2, 4, 2 notes per call-group; secondary notes are present in only half of the call-groups. _Smilisca puma_ apparently always produces at least two primary notes before emitting secondary notes; sometimes only primary notes are produced in one series of calls. The number of secondary notes following a given primary varies from one to nine; the modal number is one, and the mean is three in 27 call-groups. _Smilisca sila_ frequently begins a series of calls with two or more primary notes, but sometimes the first primary note is followed immediately by two or more secondary notes. The number of secondary notes following a given primary varies from one to five; the modal number is one, and the average is two in 13 call-groups. _Duration._--The average duration of call-groups consisting of two or more notes is 1.18 seconds in _S. baudini_; 1.02 in _cyanosticta_, 0.91 in _phaeota_, 1.32 in _puma_, 1.48 in _sila_, and 1.29 in _sordida_. Although there is considerable variation in the lengths of the notes (only primary notes in _S. puma_ and _sila_ are considered here), _S. cyanosticta_, _phaeota_, and _sordida_ have noticeably longer notes than do the other species (Table 8). The secondary notes are longer than the primary notes in _S. puma_ (average 0.27 secs. as compared with 0.13 secs.) and in _S. sila_ (average 0.25 secs., as compared with 0.16 secs.). _Note repetition rate._--The rate at which notes in call-groups containing two or more notes are produced varies in _S. baudini_ from 2.5 to 7.1 (average, 3.7) calls per second; _cyanosticta_, 1.8-2.1 (1.9); _phaeota_, 2.0-2.4 (2.2); _puma_, 1.9-2.9 (2.2); _sila_, 1.3-2.4 (1.8); and _sordida_, 1.5-2.6 (2.1). _Smilisca baudini_, which has notes of short duration (0.09 to 0.13 seconds), has the fastest note-repetition rate. Although the individual notes of _S. cyanosticta_ and _S. phaeota_ are relatively long (average, 0.38 and 0.31 seconds, respectively), the intervals between the notes is short; consequently, their note-repetition rates do not differ greatly from those of _S. puma_ and _S. sila_, which have shorter notes (average, 0.13 and 0.16 seconds, respectively) but longer intervals between notes. _Pulse rate._--Pulses vary in frequency from 78 to 240 per second in the calls analyzed (only primary notes in _S. puma_ and _S. sila_), but the variation in any given species is much less than that in the entire genus (Table 8). _Smilisca puma_ is outstanding in having a high pulse rate, which is approached only by that of _S. baudini_. Even in the species having the lowest pulse rates, the pulsations are not audible. The secondary notes produced by _S. puma_ and _S. sila_ have a slower pulse rate than the primary notes; often the pulses are audible. In _S. puma_ the pulse rate of secondary notes is sometimes as low as 48 pulses per second, and in _S. sila_ still lower (as low as 40 pulses per second). The upper limits of pulse rate in the secondary notes in these species merge imperceptibly with the rates of the primary note; consequently, on the basis of pulse rate alone it is not always possible to distinguish primary from secondary notes. _Frequency._--_Smilisca_ produces noisy (as opposed to more musical) calls, and the energy is distributed throughout the frequency spectrum; the calls are poorly modulated, except in _S. sordida_, in which two usually discrete bands of frequency are present (Pl. 11C). For the most part the calls of _Smilisca_ consist of little modified energy of the fundamental frequency and of its harmonics, some of which are emphasized. The upper frequency range varies within each species and even within the calls of one individual. _Smilisca phaeota_ has the lowest upper frequencies; no calls ranged above 4400 cycles per second (cps.), and half of the calls never exceeded 3000 cps. _Smilisca cyanosticta_ produces calls in which the upper frequency is below 7000 cps. and usually below 6000 cps. Likewise, _S. puma_ produces calls that are below 7000 cps., whereas _S. sila_ has frequencies of up to 8400 cps. In both _S. baudini_ and _S. sordida_, the highest frequencies attained are about 9100 cps. Variation in the highest frequencies in a series of consecutive calls by one individual frog was noted in all species. Such variation is especially prevalent in _S. puma_; for example one individual (KU 87771; Tape No. 376) recorded at a temperature of 24° C. at 7.5 kilometers west of Puerto Viejo, Heredia Province, Costa Rica, on July 31, 1964, produced three consecutive primary notes having upper frequencies of about 6000, 4000, and 4000 cps., respectively. Apparently in a given species the production of the higher frequencies in some notes and not in others is correlated with the amount of distention of the vocal sac and is not dependent upon the structure or tension of the vocal cords. Although the dominant frequency in _S. sordida_ is lower than that in _S. baudini_ and _S. cyanosticta_, the call of the former is audibly higher-pitched. This is due primarily to the emphasis on certain harmonics at a high frequency (sometimes as high as 9000 cps.) in _S. sordida_, whereas in _S. baudini_ and other species, if harmonics are present at those frequencies, they are not emphasized. The fundamental frequencies are as low as 90 cps. in _S. sila_ and _S. sordida_ and as high as 200 cps. in _S. puma_ (Table 8). The fundamental frequency seemingly is relatively unimportant in determining the general pitch of the call, a characteristic most dependent on the dominant frequency and emphasized harmonics in the higher-frequency spectrum. In none of the species is the fundamental the dominant frequency. In the low-pitched call of _S. phaeota_ the dominant frequency is the third harmonic (the second harmonic above the fundamental frequency, which is the first harmonic). In all other species a much higher harmonic is dominant; for examples, in _S. cyanosticta_ harmonics from 10 to 15 are dominant; in _S. baudini_, 15-19; and _S. sila_, 20-30. A glance at the audiospectrographs and their accompanying sections (Pls. 10 and 11) reveals the presence of two emphasized bands of frequency in all species except _S. phaeota_, in which only the lower band is present. These two bands of emphasized harmonics are part of a continuous, or nearly continuous, spread of energy throughout the frequency spectrum, except in _S. sordida_ in which the bands are usually distinct. As shown in the sections, certain harmonics in each of the bands are emphasized with nearly equal intensity. Therefore, with the exception of _S. phaeota_, the calls of _Smilisca_ are characterized by two major frequencies, one of which is the dominant frequency and the other is a subdominant frequency (Table 8). The upper major frequency is dominant in all calls in _S. baudini_ and _S. cyanosticta_, but either major frequency may be dominant in other species. The upper major frequency is dominant in 65 per cent of calls by _S. puma_, 87 per cent in _S. sila_, and 68 per cent in _S. sordida_. Individuals of these three species sometimes produce a series of calls in which the dominant frequency changes from one of the major frequencies to the other. Four consecutive notes emitted by an individual of _S. sordida_ recorded 13 kilometers east-northeast of Golfito, Puntarenas Province, Costa Rica, had dominant frequencies of 910, 1950, and 750 cps., respectively. In each case, an alternation of major frequencies took place in respect to dominance. An individual of _S. puma_ from 7.5 kilometers west of Puerto Viejo, Costa Rica, produced a primary note followed by one secondary note; each note had major frequencies at 600 and 1800 cps.; the dominant frequency of the primary note was at 1800 cps., whereas in the secondary note the dominant frequency was at 600 cps. The difference in emphasis on the major frequencies is so slight that shift in dominance is not audible. _Effect of temperature on calls._--The present data are insufficient to test statistically the correlation between temperature and variation within certain components of the calls in _Smilisca_, but even a crude graph shows some general correlations. The widest range of temperatures is associated with the recordings of _S. baudini_. Three individuals recorded at a temperature of 30° C. at Tehuantepec, Oaxaca, had pulse rates of 180 pulses per second and fundamental frequencies of 160-180 cps., as compared with an individual recorded at a temperature of 17° C., which had a pulse rate of 140 and a fundamental frequency of 135 cps. All individuals of _S. baudini_ recorded at higher temperatures had faster pulse rates and higher fundamental frequencies. Pulse rates differ in the other species in the genus but less strikingly (probably owing to narrower ranges of temperatures at which recordings were made). In five recordings of _S. sordida_ made at 20° C. the pulse rate is 80-90, as compared with four recordings made at 25° C. having pulse rates of 120-135. Thirteen recordings of _S. sila_ made at 17° C. have pulse rates of 97-112 (average 105); one individual recorded at 26° C. has 120 pulses per second. Seemingly no correlation exists between temperature and other characteristics of the calls, such as duration and rate of note-repetition. _The breeding call as an isolating mechanism._--Blair (1958), Bogert (1960), Duellman (1963a), Fouquette (1960), Johnson (1959), and others have provided evidence that the breeding calls of male hylids (and other anurans) serve as isolating mechanisms in sympatric species. In summarizing this discussion of the breeding calls of _Smilisca_ we want to point out what seem to be important differences in the calls that may prevent interspecific hybridization in sympatric species of _Smilisca_. The genus is readily divided into two species-groups on morphological characters; this division is supported by the breeding calls. In the species of the _baudini_ group the calls are unmodulated and lack secondary notes. In the _sordida_ group the calls either have secondary notes or are modulated. _Smilisca baudini_ occurs sympatrically with _S. cyanosticta_ and _S. phaeota_; where they occur together, both species sometimes breed in like places at the same time. We are not aware of these species breeding synchronously at exactly the same site, although _S. baudini_ and _S. cyanosticta_ were calling on the same nights and less than 100 meters apart in Oaxaca in June, 1964. Regardless of their respective breeding habits, sympatric species have calls that differ notably. Except for the higher fundamental and dominant frequencies, the calls of _S. cyanosticta_ and _S. phaeota_ closely resemble one another, but the calls of both species differ markedly from that of _S. baudini_. The geographic ranges of _S. cyanosticta_ and _S. phaeota_ are widely separated. The calls of the allopatric species _S. puma_ and _S. sila_ are not greatly different. _Smilisca sordida_ has a distinctive call and occurs sympatrically with _S. puma_ and _S. sila_. In the streams in southern Costa Rica _S. sordida_ and _S. sila_ breed synchronously, but the high-pitched modulated call of the former is notably different from the lower, unmodulated call of _S. sila_. The data indicate that the calls of related sympatric species differ more than the calls of related allopatric species. We postulate that these differences evolved to support the reproductive isolation of the sympatric species. The data are insufficient to determine geographic variation in the calls and to determine if differences in the calls are enhanced in areas of sympatry as compared with the allopatric parts of the ranges. _Other calls._--As stated previously, there is no direct evidence of territoriality in _Smilisca_; we have heard no calls that can be definitely identified as territorial. Single notes of _S. baudini_, _phaeota_, and _sila_ have been heard by day, just prior to rains, or during, or immediately after rains. Such calls can be interpreted as "rain calls," which are well known in _Hyla eximia_ and _Hyla squirella_. Distress calls are known in several species of _Rana_ and in _Leptodactylus pentadactylus_; such calls result from the rapid expulsion of air over the vocal cords and with the mouth open. Distress calls have been heard from _S. baudini_. At Charapendo, Michoacán, México, a male that had one hind limb engulfed by a _Leptodeira maculata_ emitted several long, high-pitched cries. A clasping pair of _S. baudini_ was found in a bush at the edge of a marshy stream 2 kilometers northeast of Las Cañas, Guanacaste Province, Costa Rica. When the pair was grasped, the female emitted a distress call. Eggs Eggs of _S. baudini_, _cyanosticta_, and _phaeota_ have been found in the field, and eggs of _S. sila_ have been observed in the laboratory. The eggs of _S. puma_ and _sordida_ are unknown. Insofar as known, _Smilisca baudini_ is unique in the genus in depositing the eggs in a surface film. Each egg is encased in a vitelline membrane, but individual outer envelopes are lacking. The eggs are small; the diameter of recently-deposited eggs is about 1.3 mm. and that of the vitelline membrane is about 1.5 mm. The eggs of _S. cyanosticta_ and _phaeota_ are deposited in clumps, and the eggs are larger than those of _S. baudini_. Diameters of eggs of _S. cyanosticta_ are about 2.3 mm., and those of the outer envelopes are about 4.0 mm. Artificially fertilized eggs of _S. sila_ raised in the laboratory have diameters of about 2.4 mm.; the diameter of the outer envelopes is about 4.9 mm. In order to determine the reproductive potential of the six species, ovulated eggs were removed from females and counted. The numbers of eggs recorded are: 3 _S. baudini_--2620, 2940, 3320; 1 _S. cyanosticta_--910; 3 _S. phaeota_--1665, 1870, 2010; 1 _S. puma_--518; 3 _S. sila_--369, 390, 473; 3 _S. sordida_--524, 702, 856. These limited data indicate that the large species (_S. baudini_, _cyanosticta_, and _phaeota_) have more eggs than do the smaller species. The stream-breeding species (_S. sila_ and _sordida_) have relatively few eggs by comparison with the pond-breeders. Possibly this is a function of size of eggs rather than a correlation with the site of egg-deposition. Tadpoles The acquisition of tadpoles of all of the species of _Smilisca_ has made possible the use of larval characters in erecting a classification and in estimating the phylogenetic relations of the several species. Furthermore, developmental series of tadpoles of four species allow a comparison of the growth and development in these species. Throughout the discussion of tadpoles we have referred to the various developmental stages by the Stage Numbers proposed by Gosner (1960). _General Structure_ Tadpoles of the genus _Smilisca_ are of a generalized hylid type, having 2/3 tooth-rows, unspecialized beaks, mouth partly or completely bordered by papillae, lateral fold present in the lips, spiracle sinistral, anal tube dextral, and caudal musculature extending nearly to tip of caudal fin. Although minor differences exist in coloration, proportions, and mouthparts, no great modifications of the basic structure are present. _Comparison of Species_ The larval characters of the species of _Smilisca_ are compared below and illustrated in Figures 11-15. _Shape and Proportions._--The bodies of _S. baudini_, _cyanosticta_, _phaeota_, and _puma_ are rounded and about as wide as deep; the eyes are moderately large and directed dorsolaterally, and the nostrils are about midway between the bluntly rounded snout and the eyes. The mouths are medium-sized and directed anteroventrally. The bodies of tadpoles of _S. sila_ and _sordida_ are slightly compressed dorso-ventrally. The snout is moderately long and sloping; the eyes are larger and directed more dorsally than in the other species, and the nostrils are closer to the eyes than the snout. The mouths are moderately large and directed ventrally. The tail is about half again as long as the body in _S. baudini_, _cyanosticta_, _phaeota_, and _puma_; in these species the caudal musculature is moderately heavy, and the caudal fins are deep. The caudal musculature is upturned distally in _S. baudini_ and _phaeota_, and the dorsal fin extends anteriorly onto the body in these two species and in _S. puma_. The tail is about twice as long as the body in _S. sila_ and _sordida_. In both species the caudal fins are shallow in comparison with the depth of the caudal musculature, especially in _S. sordida_ (Fig. 14); in neither species does the dorsal fin extend anteriorly onto the body. [Illustration: FIG. 11. Tadpoles of _Smilisca baudini_: (A) Stage 21 (KU 62155) × 10; (B) Stage 25 (KU 68467) × 5; (C) Stage 30 (KU 60018) × 4; (D) Stage 41 (KU 60018) × 3.] _Mouthparts._--The mouth of _S. sordida_ is completely bordered by two rows of papillae, whereas in the other species the median part of the upper lip is devoid of papillae. _Smilisca baudini_ and _puma_ have two rows of papillae; _S. sila_ has one complete row (except medially on the upper lip) and one incomplete row, and _S. cyanosticta_ and _phaeota_ have only one row (Fig. 15). All species have numerous papillae in the lateral fold; the fewest lateral papillae are found in _S. cyanosticta_ and _phaeota_. Although all species have two rows of teeth in the upper jaw and three rows in the lower jaw, specific differences in the nature of the rows exist between certain species. The second upper tooth-row is narrowly interrupted medially in _S. sila_ and _sordida_ and broadly interrupted in the other species. The first upper row is strongly arched in _S. puma_, moderately arched in _S. baudini_ and _sila_, and weakly arched in the other species. In all species the third lower tooth-row is the shortest, only slightly so in _S. sila_ and _sordida_, but only about half the length of the second lower row in _S. puma_. [Illustration: FIG. 12. Tadpoles of _Smilisca cyanosticta_: (A) Stage 21 (KU 87648) (B) Stage 25 (KU 87651) × 5; (C) Stage 30 (KU 87652) × 4; (D) Stage 40 (KU 87650) × 3.] The beaks are well developed and finely serrate in all species. The lower, broadly V-shaped, beak is slender in _S. puma_, rather robust in _S. baudini_ and _sila_, and moderately heavy in the other species. The lateral processes of the upper beak are shortest in _S. puma_ and longest in _S. baudini_ and _sordida_. In the latter the inner margin of the upper beak and lateral process have the form of a shallow S, whereas in the other species the inner margin of the upper beak forms a continuous arch with the lateral processes (Fig. 15). [Illustration: FIG. 13. Tadpoles of _Smilisca phaeota_: (A) Stage 21 (KU 68479) × 14; (B) Stage 25 (KU 68480) × 5; (C) Stage 30 (KU 68482) × 4; (D) Stage 40 (KU 68483) × 3.] _Coloration._--The tadpoles of _Smilisca_ lack the bright colors or bold markings characteristic of some hylid tadpoles; even so, the subdued colors and arrangement of pigments provide some distinctive markings by which the species can be distinguished from one another. The species comprising the _baudini_ group (_S. baudini_, _cyanosticta_, and _phaeota_) are alike in having the body brown or grayish brown dorsally and transparent with scattered brown pigment ventrally. A cream-colored, crescent-shaped mark is present on the posterior edge of the body; this mark is usually most noticeable in _S. baudini_ and least so in _S. cyanosticta_. Other differences in coloration in members of the _baudini_ group are relative and subtle. _Smilisca phaeota_ usually is more pallid than _baudini_, and _cyanosticta_ usually is darker than _baudini_; both species have larger dark markings on the tail than does _S. phaeota_. _Smilisca baudini_ has a dark streak on the middle of the anterior one-fourth of the tail (Figs. 11-13). _Smilisca puma_ is distinctive in having a grayish brown body and dark gray reticulations on the tail. _Smilisca sila_ and _sordida_ are distinctive in having pairs (sometimes interconnected) of dark marks on the dorsal surfaces of the caudal musculature, and in dorsal view the tail appears to be marked with dark and pale creamy tan transverse bars. These dark marks, as well as the small flecks on the tail, are brown in _S. sila_ and red in _sordida_. _Smilisca sila_ has dark brown flecks on the dorsal surface of the body and small white flecks laterally; these markings are absent in _S. sordida_ (Fig. 14). Descriptions of the coloration of living tadpoles are given in the accounts of the species. [Illustration: FIG. 14. Tadpoles of _Smilisca_; (A) _S. puma_, Stage 30 (KU 91807); (B) _S. sila_, Stage 25 (KU 80260); _S. sordida_, Stage 30 (KU 68475). All × 3.5.] _Growth and Development_ Information on the growth and development of Middle American hylids is scanty. Adequate descriptions have been published for _Phyllomedusa annae_ (Duellman, 1963b), _Phrynohyas venulosa_ (Zweifel, 1964), and _Triprion petasatus_ (Duellman and Klaas, 1964). Material is available for adequate descriptions of the developmental stages of four species of _Smilisca_ (Tables 9-12, Figs. 11-13). Because none of the tadpoles was raised from hatching to metamorphosis, the rate of growth and duration of the larval stages are unknown. [Illustration: FIG. 15. Mouthparts of tadpoles of _Smilisca_; (A) _S. baudini_ (KU 60018); (B) _S. puma_ (KU 91807); (C) _S. cyanosticta_ (KU 87625); (D) _S. sila_ (KU 80620); (E) _S. phaeota_ (KU 68482); (F) _S. sordida_ (KU 68475). All ×17.] Table 9.--Growth and Development of Tadpoles of Smilisca baudini. (Means Are Given in Parentheses After the Observed Ranges.) ==================================================================== Stage | N | Total length | Body length | Tail length -------------------------------------------------------------------- 21 |10 | 5.1-5.4 (5.22) | 2.6-2.7 (2.54) | 2.5-2.7 (2.58) 24 |10 | 6.0-6.5 (6.20) | 2.3-2.6 (2.45) | 3.5-3.9 (3.69) 25 |10 | 7.2-8.3 (7.78) | 3.0-3.3 (3.14) | 4.2-5.0 (4.64) 27 |10 | 18.5-21.5 (20.22) | 8.0-9.0 (8.38) |10.4-13.0 (11.84) 29 |10 | 21.5-24.5 (22.60) | 8.5-10.0 (9.25) |12.5-14.5 (13.35) 37 | 3 | 28.5-31.0 (30.00) |11.0-12.5 (11.67) |17.5-19.0 (18.00) 38 |10 | 35.0-37.5 (35.50) |12.0-13.5 (12.80) |21.5-24.0 (22.70) 40 | 2 | 34.0-37.0 (35.50) |12.5-13.5 (13.00) |21.5-23.5 (22.50) 41 |10 | 34.0-37.0 (35.50) |12.5-13.5 (13.00) |21.5-23.5 (22.50) 42 | 3 | 24.0-30.0 (27.00) |12.5-13.0 (12.67) |11.5-17.0 (14.33) 45 | 6 | 14.0-24.0 (17.58) |12.5-14.0 (13.37) | 1.5-10.0 (4.17) 46 |23 | ---- |12.0-15.5 (13.34) | ---- -------------------------------------------------------------------- Table 10.--Growth and Development of Tadpoles of Smilisca cyanosticta. (Means Are Given in Parentheses After the Observed Ranges.) ====================================================================== Stage | N | Total length | Body length | Tail length ---------------------------------------------------------------------- 21 | 10| 5.8-6.5 (6.28) | 2.8-3.1 (3.00) | 3.0-3.5 (3.28) 25 | 10| 7.9-9.2 (8.44) | 2.7-3.2 (2.96) | 4.8-6.0 (5.48) 30 | 7| 22.5-25.0 (23.50) | 8.5-9.5 (9.00) |14.0-15.5 (14.57) 36 | 10| 27.0-30.0 (28.75) | 9.5-11.5 (10.80) |17.0-18.5 (17.95) 42 | 2| 26.0-27.0 (26.50) | 10.00 |16.0-17.0 (16.50) 46 | 2| -- | 14.00 | -- ---------------------------------------------------------------------- Hatchlings of three species (_S. baudini_, _cyanosticta_, and _phaeota_) are available. These larvae have non-functional eyes and large oral suckers. By the time the larvae have developed to stage 21, external gills are present, the caudal musculature and caudal fin have been differentiated, and the head is distinguishable from the body. In stage 21 oral suckers and a large amount of yolk are still present. The developmental data on the four species show no significant variations; consequently, we will describe the development of only one species, _Smilisca phaeota_ (Table 11, Figs. 13 and 16). _Stage 21._--Bulging cream-colored yolk mass, transparent cornea, and moderately long, unbranched filamentous gills, and oral suckers present; mouth having irregular papillae on lower lip; teeth and beaks absent; caudal myomeres distinct; pigmentation uniform over body and caudal musculature; caudal fin transparent with scattered small flecks. [Illustration: FIG. 16. Relative rate of growth in tadpoles of _Smilisca phaeota_ as correlated with developmental stages. Formulas for the limb bud refer to its length (L) in relation to basal diameter (D).] _Stage 25._--Operculum complete; gills absent; sinistral spiracle apparently functional; cloacal tail-piece, nasal capsules, and external nares present; gut partly formed; mouth bordered by single row of papillae, except medially; small papillae present in lateral fold of lips; two upper and three lower tooth-rows present, but not fully developed; beaks apparently fully developed; depth of dorsal and ventral fins less than depth of caudal musculature: tip of tail upturned; pigment on body most dense on dorsum and sides; faint, nearly pigmentless crescent-shaped mark on posterior edge of body; concentrations of pigment forming small spots on tail. _Stage 28._--Mouthparts complete; limb bud about half as long as thick; other structural features and coloration closely resemble those in stage 25. _Stage 30._--Limb bud approximately twice as long as thick; body as deep as wide; dorsal fin deepest just posterior to body; ventral fin deeper than caudal musculature; tail sharply upturned distally; anal tube dextral; brown pigment sparse on flanks. Table 11.--Growth and Development of Tadpoles of Smilisca phaeota. (Means Are Given in Parentheses After the Observed Ranges.) ==================================================================== Stage | N | Total length | Body length | Tail length -------------------------------------------------------------------- 15 | 10| -- | 1.9-2.1 (1.97) | -- 16 | 8| -- | 2.0-2.2 (2.07) | -- 18 | 4| -- | 2.2-2.6 (2.31) | -- 21 | 3| 7.9-8.6 (8.21) | 4.1-4.5 (4.31) | 3.8-4.1 (3.92) 25 | 10| 8.7-10.6 (9.69) | 4.5-4.8 (4.64) | 4.3-6.0 (5.05) 26 | 11| 12.3-16.1 (14.01) | 4.2-6.3 (5.60) | 6.7-9.8 (8.41) 27 | 10| 13.0-15.7 (14.28) | 4.9-6.2 (5.40) | 7.7-10.5 (8.88) 28 | 13| 13.9-20.9 (15.62) | 5.2-8.3 (5.75) | 8.5-12.6 (9.85) 29 | 8| 17.8-22.3 (19.79) | 6.3-8.4 (7.19) | 11.5-14.0 (12.60) 30 | 9| 20.3-24.8 (22.85) | 8.1-10.5 (9.32) | 10.5-15.5 (13.53) 31 | 5| 24.1-28.5 (26.61) | 9.4-11.2 (10.59) | 14.7-17.3 (16.02) 34 | 5| 24.8-29.4 (27.31) | 9.2-11.6 (10.73) | 15.6-18.5 (16.80) 36 | 3| 30.0-30.1 (30.07) |10.1-12.2 (11.15) | 18.9-20.0 (19.44) 37 | 4| 28.9-34.1 (31.75) |11.5-12.4 (11.88) | 17.4-22.5 (19.88) 38 | 1| 28.98 |12.88 | 16.10 39 | 2| 35.6-36.9 (36.25) |14.00 | 21.6-22.9 (22.25) 40 | 2| 32.3-39.8 (36.05) |14.00 | 18.3-21.8 (20.05) 43 | 2| 21.5-23.0 (22.25) |14.2-14.8 (14.45) | 6.8-8.8 (7.80) 44 | 4| -- |14.5-15.6 (15.08) | -- 46 | 11| -- |12.7-16.7 (14.26) | -- -------------------------------------------------------------------- Table 12.--Growth and Development of Tadpoles of Smilisca sordida. (Means Are Given in Parentheses After the Observed Ranges.) =======+===+==================+==================+================= Stage | N | Total length | Body length | Tail length -------+---+------------------+------------------+----------------- 25 | 6 | 25.5-28.0 (26.1) | 9.0-9.5 (9.3) | 16.2-18.5 (16.7) 33 | 2 | 28.5-30.0 (29.3) | 10.2-10.5 (10.4) | 18.0-19.8 (18.9) 36 | 8 | 29.5-34.5 (32.3) | 10.2-11.7 (10.8) | 19.3-23.0 (21.5) 37 | 7 | 31.6-37.5 (34.6) | 11.0-12.5 (11.5) | 21.6-25.0 (23.2) 41 | 3 | 33.0-37.2 (35.2) | 11.6-12.2 (11.9) | 21.4-25.2 (23.2) 43 | 1 | ---- | 12.4 | ---- 46 | 9 | ---- | 13.1-15.7 (14.9) | ---- -------+---+------------------+------------------+----------------- _Stages 34_, _36_, _37_, and _38_.--Stage 34, foot paddle-shaped with four toe buds; stage 36, five toe buds; stages 37 and 38, lengthening of toes. In all four stages, spiracle persistent, and pigmentation resembling that of early stages. _Stage 39._--Metatarsal tubercle present; greatest total length (36.9 mm.) attained. _Stage 40._--Subarticular tubercles prominent; skin over forelimbs transparent; cloacal tail-piece and spiracle absent; outer tooth-rows degenerating; caudal fins shallower than in preceding stages; distal part of tail nearly straight; size of dark markings on tail decreased; pigment present on hind limb. _Stage 43._--Forelimbs erupted; larval mouthparts absent; corner of mouth between nostril and eye; transverse bands present on hind limbs; tail greatly reduced (about 8 mm. in length). _Stage 44._--Sacral hump barely noticeable; tail reduced to a stub; corner of mouth at level of pupil of eye; dorsal surfaces pale olive-green; venter white. Changes proceed in a definite pattern during the growth and development of tadpoles. Larval teeth are absent in hatchlings; the inner tooth-rows develop first, and the third lower row last. At metamorphosis the third lower row is the first to be lost. The tail increases gradually in length relative to the body. In stage 25 the tail is 52.1 per cent of the total length, and in stage 36, 64.6 per cent. In later stages the tail becomes relatively shorter through resorption. Duellman and Klaas (1964:320) noted a great size-variation in _Triprion_ tadpoles in stage 25. No such variation is apparent in any stage of any of the species of _Smilisca_ studied. The growth and development of the other species of _Smilisca_ do not differ significantly from that of _S. phaeota_. The tadpoles of _S. sila_ and _sordida_ from streams have relatively longer tails at hatching. For example, in tadpoles of _S. sordida_ the average length of tail is 64.0 per cent of the body-length in stage 25, and in stage 37, 67.0 per cent. _Behavior_ The tadpoles of _S. baudini_, _cyanosticta_, _phaeota_, and _puma_ are pelagic inhabitants of shallow ponds. Early stages of _S. baudini_ in which external gills are present have been observed to hang vertically with the gills spread out at the surface of the water, a behavior noted by Zweifel (1964:206) in tadpoles of _Phrynohyas venulosa_, which also develop in warm, standing water having a relatively low oxygen-tension. When disturbed the pelagic tadpoles usually dive and seek shelter amidst vegetation or in mud on the bottom. This behavior was observed in _S. baudini_, _cyanosticta_, and _phaeota_ by day and at night. No tadpoles of _S. puma_ were observed by day; those seen at night were near the surface of small water-filled depressions in a grassy marsh; they responded to light by taking refuge in the dense grass. Perhaps tadpoles of this species are negatively phototactic and remain hidden by day. The stream-inhabiting tadpoles of _S. sila_ and _sordida_ live in clear pools in rocky streams, where they were observed to cling by their mouths to rocks in the stream and to seek shelter amidst pebbles or beneath rocks and leaves on the bottom. These tadpoles are not found in shallow riffles. We have not found tadpoles of two species of _Smilisca_ in the same body of water and therefore cannot offer observations on ecological relationships in sympatric situations. PHYLOGENETIC RELATIONSHIPS Identifiable hylid remains are known from the Miocene to the Recent, but these fossils are mostly fragmentary and provide little useful information regarding the phylogenetic relationships of living genera. Frogs of the genus _Smilisca_ are generalized and show no striking adaptations, either in their structure or in their modes of life history. Interspecific Relationships In attempting to understand the relationships of the species of _Smilisca_ we have emphasized osteological characters. The phylogeny suggested by these characters is supported by other lines of evidence, including external morphology, tadpoles, and breeding calls. Our concept of the prototype of the genus _Smilisca_ is a moderate-sized hylid having: (1) a well-developed frontoparietal fontanelle, (2) frontoparietal lacking lateral processes, (3) no bony squamosal-maxillary arch, (4) a fully ossified ethmoid, (5) paired subgular vocal sac, (6) moderately webbed fingers and toes, (7) relatively few supernumerary tubercles on the digits, (8) eggs deposited in clumps in ponds, (9) anteroventral mouth in tadpoles bordered by one row of labial papillae, but median part of upper lip bare, (10) tail relatively short and deep in tadpoles, and (11) a breeding call consisting of a series of like notes. Two phyletic lines evolved from this prototype. The first of these was the stock that gave rise to the _baudini_ group. The evolutionary changes that took place in this line included increase in size, development of a lateral curvature of the maxillary, and an increased amount of cranial ossification, especially in the dermal roofing bones. This phyletic line retained the larval characters and breeding call of the prototype. The second phyletic line gave rise to the _sordida_ group and diverged from the prototype in the development of an angular maxillary and a breeding call consisting of a primary note followed by secondary notes. The frogs in this phyletic line retained the moderate size of the prototype and did not develop additional dermal bone. Our concept of the phylogenetic relationships is shown graphically in Figure 17. Within the _baudini_ group one stock retained separate nasals and did not develop a bony squamosal-maxillary arch, but broad lateral processes developed on the frontoparietals. The tadpoles remained unchanged from the primitive type. This stock evolved into _S. phaeota_. In the other stock the nasals became fully ossified and a bony squamosal-maxillary arch developed. One branch of this second stock retained tadpoles having only one row of labial papillae and did not develop lateral processes on the frontoparietals; this branch evolved into _S. cyanosticta_. The other branch diverged and gave rise to _S. baudini_ by developing relatively shorter hind legs, large lateral processes on the frontoparietals, and tadpoles having two rows of labial papillae. Within the _sordida_ group the cranial features remained unchanged in one line, which gave rise to _S. sila_, whereas in a second line the nasals were reduced, and their long axes shifted with the result that they are not parallel to the maxillaries; the amount of ossification of the ethmoid was reduced, and the tadpoles developed two rows of labial papillae. In this second line one branch retained the pond-breeding habits and gave rise to _S. puma_, whereas a second branch became adapted to stream-breeding and gave rise to _S. sordida_. _baudini_ \ _cyanosticta_ \ / + _phaeota_ _sordida_ \ / / + puma_ / \ \/ _sila_ \ /_____/ \ / \ / \ / | | Prototype [Illustration: FIG. 17. Hypothesized phylogenetic relationships of the species of _Smilisca_.] Certain aspects of this proposed phylogeny warrant further comment. Features such as the deposition of additional bone that roofs the skull or that forms lateral projections from the frontoparietals, like those in _S. baudini_ and _phaeota_, are minor alterations of dermal elements and not basic modifications of the architecture of the skull. Consequently, we hypothesize the independent development of these dermal changes in _S. baudini_ and _phaeota_. Similar kinds of dermal modifications have evolved independently in many diverse groups of frogs. Likewise, we propose the parallel development of stream-adapted tadpoles in _S. sordida_ and _sila_; in both cases the tadpoles adapted to changing environmental conditions (see following section on evolutionary history). Tadpoles of _S. sordida_ already had two rows of labial papillae before entering the streams; subsequently the tadpoles developed complete rows of papillae, ventral mouths and long tails having low fins. Possibly the tadpoles of _S. sila_ had two rows of labial papillae prior to their adapting to stream conditions; in the process of adapting they developed ventral mouths and long tails having low fins. Similar modifications in tadpoles have occurred in many diverse groups of Middle American hylids, such as _Plectrohyla_, _Ptychohyla_, the _Hyla uranochroa_ group, and the _Hyla taeniopus_ group. Our lack of concern about coloration is due to the fact that, with the exception of the blue spots on the flanks and posterior surfaces of the thighs in some species, the coloration of _Smilisca_, consisting of a pattern of irregular dark marks on a paler dorsum and dark transverse bars on the limbs, is not much different from that of many other Neotropical hylids. Blue is a structural color, rare among Amphibia, which is achieved by the absence of lipophores above the guanophores. Thus, the incident light rays at the blue end of the spectrum are reflected by the guanophores without interference by an overlying yellow lipophore screen. According to Noble (1931), lipophores are capable of amoeboid movement that permits shifts in their positions, between or beneath the guanophores. We do not know whether this behavior of lipophores is widespread and is effected in response to environmental changes, or whether it is a genetically controlled attribute that is restricted in appearance. If the latter is the case we must assume that the prototype of _Smilisca_ possessed such an attribute which was lost in _S. baudini_, _phaeota_, and _puma_. The development of blue spots is not constant in _S. sordida_ and _S. sila_; in _S. cyanosticta_ the spots range in color from blue to pale green. The coloration of the tadpoles is not distinctive, except for the presence of dorsal blotches on the tails of _S. sila_ and _sordida_. However, the similarity in pattern cannot be interpreted as indicating close relationships because nearly identical patterns are present in _Hyla legleri_ and some species of _Prostherapis_. This disruptive coloration seems to be directly associated with the pebble-bottom, stream-inhabiting tadpoles. In the _baudini_ group, _S. phaeota_ and _cyanosticta_ are allopatric, whereas _S. baudini_ occurs sympatrically with both of those species. The call of _S. baudini_ differs notably from the calls of _S. phaeota_ and _cyanosticta_, which are more nearly alike. Although in the phylogenetic scheme proposed here _S. sila_ is considered to be more distantly related to _S. puma_ than is _S. sordida_, the calls of _S. sila_ and _puma_ more closely resemble one another than either resembles that of _S. sordida_. _Smilisca sila_ and _puma_ are allopatric, whereas _S. sordida_ is broadly sympatric with both of those species. We assume that in their respective phyletic lines the differentiation of both _S. baudini_ and _sordida_ was the result of genetic changes in geographically isolated populations. Subsequently, each species dispersed into areas inhabited by other members of their respective groups. Selection for differences in the breeding calls helped to reinforce other differences in the populations and thereby aided in maintaining specificity. Evolutionary History With respect to temporal and spatial aspects of evolution in _Smilisca_, we have tried to correlate the phylogenetic evidence on _Smilisca_ with the geologic data on Middle America presented by Lloyd (1963), Vinson and Brineman (1963), Guzmán and Cserna (1963), Maldonado-Koerdell (1964), and Whitmore and Stewart (1965). Likewise, we have borne in mind the evidence for, and ideas about, the evolution of the Middle American herpetofauna given by Dunn (1931b), Schmidt (1943), Stuart (1950, 1964) Duellman (1958, MS), and Savage (MS). According to Stuart's (1950) historical arrangement of the herpetofauna, _Smilisca_ is a member of the Autochthonous Middle American Faunal Element, and according to Savage's (MS) arrangement the genus belongs to the Middle American Element, a fauna which was derived from a generalized tropical American unit that was isolated in tropical North America by the inundation of the Isthmian Link in early Tertiary, that developed _in situ_ in tropical North America, and that was restricted to Middle America by climatic change in the late Cenozoic. Savage (MS) relied on the paleogeographic maps of Lloyd (1963) to hypothesize the extent and centers of differentiation of the Middle American Faunal Element. According to Lloyd's concept, Middle America in the Miocene consisted of a broad peninsula extending southeastward to about central Nicaragua, separated from the Panamanian Spur of continental South America by shallow seas. A large island, the Talamanca Range, and remnants of the Guanarivas Ridge formed an archipelago in the shallow sea. The recent discovery of remains of mammals having definite North American affinities in the Miocene of the Canal Zone (Whitmore and Stewart, 1965) provides substantial evidence that at least a peninsula was continuous southeastward from Nuclear Central America to the area of the present Canal Zone in early mid-Miocene time. South America was isolated from Central America by the Bolivar Trough until late mid-Pliocene. Thus, in the mid-Tertiary the broad peninsula of Nuclear Central America, which consisted of low and moderately uplifted regions having a tropical mesic climate, provided the site for the evolution of _Smilisca_. It is not possible to determine when the genus evolved, but to explain the differentiation of the species it is unnecessary to have the ancestral _Smilisca_ present prior to the Miocene. We view the Miocene _Smilisca_ as the prototype described in the preceding section, and suppose that it lived in the mesic tropical environment of the eastern part of the Central American Peninsula (in what is now Costa Rica and western Panamá). Two stocks differentiated, probably in middle Miocene times; one of these, the ancestral stock of the _baudini_ group, was widespread on the Caribbean lowlands from the Nicaraguan Depression to the Bolivar Trough, and the other, the ancestral stock of the _sordida_ group, was restricted to the Pacific lowlands of the same region. In late Miocene time the ancestral stock of the _baudini_ group dispersed northwestward around the deep embayment in the Nicaraguan depression into upper Central America (in what is now Honduras and Guatemala) and thence into southern México. Apparently differentiation took place on each side of the Nicaraguan Depression; the frogs to the south of the depression evolved into _S. phaeota_, whereas those to the north of the depression represented the stock from which _S. baudini_ and _cyanosticta_ arose. Prior to the uplift of the mountains in the late Miocene and the Pliocene the _baudini-cyanosticta_ stock probably was widespread in northwestern Central America. The elevation of the mountains resulted in notable climatic changes, principally the development of sub-humid environments on the Pacific lowlands. The frogs living on the Pacific lowlands became adapted to sub-humid conditions and developed into _S. baudini_. The stock on the Caribbean lowlands remained in mesic environments and evolved into _S. cyanosticta_. Possibly in the middle Miocene before the Talamanca Range in Costa Rica and western Panamá was greatly uplifted, the ancestral stock of the _sordida_ group invaded the Caribbean lowlands of what is now Costa Rica. The subsequent elevation of the Talamanca Range in the Pliocene effectively isolated the ancestral stock of _S. sila_ on the Pacific lowlands from the _puma-sordida_ stock on the Caribbean lowlands. The former was subjected to the sub-humid conditions which developed on the Pacific lowlands when the Talamanca Range was uplifted. It adapted to the sub-humid environment by living along streams and evolving stream-adapted tadpoles. On the Caribbean side of the Talamanca Range the _puma-sordida_ stock inhabited mesic environments. The stock that evolved into _S. puma_ remained in the lowlands as a pond-breeding frog, whereas those frogs living on the slopes of the newly elevated mountains became adapted for their montane existence by developing stream-adapted tadpoles and thus differentiated into _S. sordida_. Probably the six species of _Smilisca_ were in existence by the end of the Pliocene; at that time a continuous land connection existed from Central America to South America. The climatic fluctuations in the Pleistocene, and the post-Wisconsin development of present climatic and vegetational patterns in Middle America, brought about the present patterns of distribution of the species. From its place of origin on the Caribbean lowlands of lower Central America, _S. phaeota_ dispersed northward into Nicaragua and southward along the Pacific slopes of northwestern South America. Perhaps in the late Pleistocene or in post-Wisconsin time when mesic conditions were more widespread than now, _S. phaeota_ moved onto the Pacific lowlands of Costa Rica. Its route could have been through the Arenal Depression. Subsequent aridity restricted its range on the Pacific lowlands to the Golfo Dulce region. Climatic fluctuation in northern Central America restricted the distribution of _S. cyanosticta_ to mesic habitats on the slopes of the Mexican and Guatemalan highlands and to certain humid areas on the lowlands. _Smilisca baudini_ was well adapted to sub-humid conditions, and the species dispersed northward to the Rio Grande Embayment and to the edge of the Sonoran Desert and southward into Costa Rica. In southern México and Central America the species invaded mesic habitats. Consequently, in some areas it is sympatric with _S. cyanosticta_ and _phaeota_. _Smilisca puma_ dispersed northward onto the Caribbean lowlands of southern Nicaragua. Its southward movements probably were limited by the ridges of the Talamanca Range that extend to the Caribbean coast in the area of Punta Cahuita in Costa Rica. _Smilisca sila_ dispersed along the Pacific lowlands and slopes of the mountains from eastern Costa Rica and western Panamá through eastern Panamá to northern Colombia. Climatic fluctuation in the Pleistocene evidently provided sufficient altitudinal shifts in environments in the Talamanca Range to permit _S. sordida_ to move onto the Pacific slopes. From its upland distribution the species followed streams down to both the Caribbean and Pacific lowlands, where it is sympatric with _S. puma_ on the Caribbean lowlands and _S. sila_ on the Pacific lowlands. The evolution of the species-groups of _Smilisca_ was effected through isolation by physical barriers in the Cenozoic; the differentiation of the species was initiated by further isolation of populations by changes in physiography and climate. Present patterns of distribution resulted from Pleistocene and post-Wisconsin climatic changes. Today, sympatric species have different breeding habits and breeding calls which reinforce the differences in morphology. SUMMARY AND CONCLUSIONS The genus _Smilisca_ is composed of six species of tree frogs; each species is defined on the basis of adult morphology, larval characters, and breeding behavior. Keys are provided to aid in the identification of adults and of tadpoles. Analysis of the characters and examination of type specimens indicates that several currently-recognized taxa are synonymous, as follows: 1. _Hyla beltrani_ Taylor, 1942 = _Smilisca baudini_. 2. _Hyla gabbi_ Cope, 1876 = _Smilisca sordida_. 3. _Hyla manisorum_ Taylor, 1954 = _Smilisca baudini_. 4. _Hyla nigripes_ Cope, 1876 = _Smilisca sordida_. 5. _Hyla wellmanorum_ Taylor, 1952 = _Smilisca puma_. _Smilisca phaeota cyanosticta_ Smith, 1953 is elevated to specific rank, and one new species, _Smilisca sila_, is named and described. The skeletal system of developmental stages and the adult of _Smilisca baudini_ is described, and the skull is compared with that of other members of the genus. The tadpoles are described, compared, and illustrated; the larval development of _Smilisca phaeota_ is described. Breeding behavior and breeding calls are described and compared. Some species of _Smilisca_ have breeding choruses. Two species, _S. sila_ and _sordida_, breed in streams, whereas the others breed in ponds. The genus is considered to be part of the Middle American Faunal Element; the species are thought to have differentiated in response to ecological diversity and historical opportunities provided by Cenozoic changes in physiography and climate. LITERATURE CITED BAIRD, S. F. 1854. Descriptions of new genera and species of North American frogs. Proc. Acad. Nat. Sci. Philadelphia, 7:59-62. April 27. 1859. Reptiles of the boundary. United States and Mexican boundary survey. Washington, D. C., p. 35, pl. 41. BALDAUF, R. J. 1959. Morphological criteria and their use in showing bufonid phylogeny. Jour. Morph., 104:527-560. May. BARBOUR, T. 1923. Notes on reptiles and amphibians from Panama. Occas. Papers Mus. Zool. Univ. Michigan, 129:1-16. January 25. BLAIR, W. F. 1959. Call structure and species groups in U. S. treefrogs (_Hyla_). Southwest. Nat., 3:77-89. June 1, 1959. 1962. 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H. 1942. New Caudata and Salientia from México. Univ. Kansas Sci. Bull., 28:295-323. November 15. 1952. The frogs and toads of Costa Rica. Univ. Kansas Sci. Bull., 35:577-942. July 1. 1954. Additions to the known herpetological fauna of Costa Rica with comments on other species. No. I. Univ. Kansas Sci. Bull., 36:597-639. June 1. TAYLOR, E. H. and SMITH, H. M. 1945. Summary of the collections of amphibians made in México under the Walter Rathbone Bacon Traveling Scholarship. Proc. U. S. Natl. Mus., 95:521-613, pls. 18-32. June 30. TIHEN, J. A. 1962. Osteological observations on New World Bufo. Amer. Midl. Nat., 67:157-183. January. 1965. Evolutionary trends in frogs. Amer. Zoologist, 5:309-318. VINSON, G. L. and BRINEMAN, J. H. 1963. Nuclear Central America, hub of Antillean Transverse Belt. Amer. Assoc. Petrol. Geol., Mem. 2:101-112. WHITMORE, F. C., JR. and STEWART, R. H. 1965. Miocene mammals and Central American seaways. Science, 148:180-185. April 9. ZWEIFEL, R. G. 1956. Two pelobatid frogs from the Tertiary of North America and their relationships to fossil and Recent forms. Amer. Mus. Novitates, 1762:1-45. April 6. 1958. Results of the Archbold Expeditions. No. 78. Frogs of the Papuan hylid genus _Nyctimystes_. Amer. Mus. Novitates, 1896:1-51. July 22. 1964. Life history of _Phrynohyas venulosa_ (Salientia: Hylidae) in Panamá. Copeia, no. 1:201-208. March 26. _Transmitted March 14, 1966._ [] 31-3430 UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Institutional libraries interested in publications exchange may obtain this series by addressing the Exchange Librarian, University of Kansas Library, Lawrence, Kansas. Copies for individuals, persons working in a particular field of study, may be obtained by addressing instead the Museum of Natural History, University of Kansas, Lawrence, Kansas. 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Eaton, Jr. Pp. 155-180, 10 figures in text. July 10, 1959. 3. The baculum in microtine rodents. By Sidney Anderson. Pp. 181-216, 49 figures in text. February 19, 1960. *4. A new order of fishlike Amphibia from the Pennsylvanian of Kansas. By Theodore H. Eaton, Jr., and Peggy Lou Stewart. Pp. 217-240, 12 figures in text. May 2, 1960. 5. Natural history of the Bell Vireo, Vireo bellii Audubon. By Jon C. Barlow. Pp. 241-296, 6 figures in text. March 7, 1962. 6. Two new pelycosaurs from the lower Permian of Oklahoma. By Richard C. Fox. Pp. 297-307, 6 figures in text. May 21, 1962. 7. Vertebrates from the barrier island of Tamaulipas, México. By Robert K. Selander, Richard F. Johnston, B. J. Wilks, and Gerald G. Raun. Pp. 309-345, pls. 5-8. June 18, 1962. 8. Teeth of edestid sharks. By Theodore H. Eaton, Jr. Pp. 347-362, 10 figures in text. October 1, 1962. 9. Variation in the muscles and nerves of the leg in two genera of grouse (Tympanuchus and Pedioecetes). By E. Bruce Holmes. Pp. 363-474, 20 figures in text. October 25, 1963. $1.00. 10. A new genus of Pennsylvanian fish (Crossopterygii, Coelacanthiformes) from Kansas. By Joan Echols. Pp. 475-501, 7 figures in text. October 25, 1963. 11. Observations on the Mississippi kite in southwestern Kansas. By Henry S. Fitch. Pp. 503-519. October 25, 1963. 12. Jaw musculature of the Mourning and White-winged doves. By Robert L. Merz. Pp. 521-551, 22 figures in text. October 25, 1963. 13. Thoracic and coracoid arteries in two families of birds, Columbidae and Hirundinidae. By Marion Anne Jenkinson. Pp. 553-573, 7 figures in text. March 2, 1964. 14. The breeding birds of Kansas. By Richard F. Johnston. Pp. 575-655, 10 figures in text. May 18, 1964. 75 cents. 15. The adductor muscles of the jaw in some primitive reptiles. By Richard C. Fox. Pp. 657-680, 11 figures in text. May 18, 1964. Index. Pp. 681-694. Vol. 13. 1. Five natural hybrid combinations in minnows (Cyprinidae). By Frank B. Cross and W. L. Minckley. Pp. 1-18. June 1, 1960. 2. A distributional study of the amphibians of the Isthmus of Tehuantepec, México. By William E. Duellman. Pp. 19-72, pls. 1-8, 3 figures in text. August 16, 1960. 50 cents. 3. A new subspecies of the slider turtle (Pseudemys scripta) from Coahuila, México. By John M. Legler. Pp. 73-84, pls. 9-12, 3 figures in text. August 16, 1960. *4. Autecology of the copperhead. By Henry S. Fitch. Pp. 85-288, pls. 13-20, 26 figures in text. November 30, 1960. 5. Occurrence of the garter snake, Thamnophis sirtalis, in the Great Plains and Rocky Mountains. By Henry S. Fitch and T. Paul Maslin. Pp. 289-308. 4 figures in text. February 10, 1961. 6. Fishes of the Wakarusa River in Kansas. By James E. Deacon and Artie L. Metcalf. Pp. 309-322, 1 figure in text. February 10, 1961. 7. Geographic variation in the North American cyprinid fish, Hybopsis gracilis. By Leonard J. Olund and Frank B. Cross. Pp. 323-348, pls. 21-24, 2 figures in text. February 10, 1961. 8. Descriptions of two species of frogs, genus Ptychohyla; studies of American hylid frogs, V. By William E. Duellman. Pp. 349-357, pl. 25, 2 figures in text. April 27, 1961. 9. Fish populations, following a drought, in the Neosho and Marais des Cygnes rivers of Kansas. By James Everett Deacon. Pp. 359-427, pls. 26-30, 3 figures in text. August 11, 1961. 75 cents. 10. North American recent soft-shelled turtles (Family Trionychidae). By Robert G. Webb. Pp. 429-611, pls. 31-54, 24 figures in text. February 16, 1962. $2.00. Index. Pp. 613-624. Vol. 14. 1. Neotropical bats from western México. By Sydney Anderson. Pp. 1-8. October 24, 1960. 2. Geographical variation in the harvest mouse, Reithrodontomys megalotis, on the central Great Plains and in adjacent regions. By J. Knox Jones, Jr., and B. Mursaloglu. Pp. 9-27, 1 figure in text. July 24, 1961. 3. Mammals of Mesa Verde National Park, Colorado. By Sydney Anderson. Pp. 29-67, pls. 1 and 2, 3 figures in text. July 24, 1961. 4. A new subspecies of the black myotis (bat) from eastern México. By E. Raymond Hall and Ticul Alvarez. Pp. 69-72, 1 figure in text. December 29, 1961. 5. North American yellow bats, "Dasypterus," and a list of the named kinds of the genus Lasiurus Gray. By E. Raymond Hall and J. Knox Jones, Jr. Pp. 73-98, 4 figures in text. December 29, 1961. 6. Natural history of the brush mouse (Peromyscus boylii) in Kansas with description of a new subspecies. By Charles A. Long. Pp. 99-110, 1 figure in text. December 29, 1961. 7. Taxonomic status of some mice of the Peromyscus boylii group in eastern México, with description of a new subspecies. By Ticul Alvarez. Pp. 111-120, 1 figure in text. December 29, 1961. 8. A new subspecies of ground squirrel (Spermophilus spilosoma) from Tamaulipas, Mexico. By Ticul Alvarez. Pp. 121-124. March 7, 1962. 9. Taxonomic status of the free-tailed bat, Tadarida yucatanica Miller. By J. Knox Jones, Jr., and Ticul Alvarez. Pp. 125-133, 1 figure in text. March 7, 1962. 10. A new doglike carnivore, genus Cynarctus, from the Clarendonian, Pliocene, of Texas. By E. Raymond Hall and Walter W. Dalquest. Pp. 135-138. 2 figures in text. April 30, 1962. 11. A new subspecies of wood rat (Neotoma) from northeastern Mexico. By Ticul Alvarez. Pp. 139-143. April 30, 1962. 12. Noteworthy mammals from Sinaloa, Mexico. By J. Knox Jones, Jr., Ticul Alvarez, and M. Raymond Lee. Pp. 145-159, 1 figure in text. May 18, 1962. 13. A new bat (Myotis) from Mexico. By E. Raymond Hall. Pp. 161-164, 1 figure in text. May 21, 1962. *14. The mammals of Veracruz. By E. Raymond Hall and Walter W. Dalquest. Pp. 165-362, 2 figures in text. May 20, 1963. $2.00. 15. The Recent mammals of Tamaulipas, México. By Ticul Alvarez. Pp. 363-473, 5 figures in text. May 20, 1963. $1.00. 16. A new subspecies of the fruit-eating bat, Sturnira ludovici, from western Mexico. By J. Knox Jones, Jr., and Gary L. Phillips. Pp. 475-481, 1 figure in text. March 2, 1964. 17. Records of the fossil mammal Sinclairella, Family Apatemyidae, from the Chadronian and Orellan. By William A. Clemens, Jr. Pp. 483-491, 2 figures in text. March 2, 1964. 18. The mammals of Wyoming. By Charles A. Long. Pp. 493-758, 82 figures in text. July 6, 1965. $3.00. Index. Pp. 759-784. Vol. 15. 1. The amphibians and reptiles of Michoacán, México. By William E. Duellman. Pp. 1-148, pls. 1-6, 11 figures in text. December 20, 1961. $1.50. 2. Some reptiles and amphibians from Korea. By Robert G. Webb, J. Knox Jones, Jr., and George W. Byers. Pp. 149-173. January 31, 1962. 3. A new species of frog (genus Tomodactylus) from western México. By Robert G. Webb. Pp. 175-181, 1 figure in text. March 7, 1962. 4. Type specimens of amphibians and reptiles in the Museum of Natural History, The University of Kansas. By William E. Duellman and Barbara Berg. Pp. 183-204. October 26, 1962. 5. Amphibians and reptiles of the rainforests of southern El Petén, Guatemala. By William E. Duellman. Pp. 205-249, pls. 7-10, 6 figures in text. October 4, 1963. 6. A revision of snakes of the genus Conophis (Family Colubridae, from Middle America). By John Wellman. Pp. 251-295, 9 figures in text. October 4, 1963. 7. A review of the Middle American tree frogs of the genus Ptychohyla. By William E. Duellman. Pp. 297-349, pls. 11-18, 7 figures in text. October 18, 1963. 50 cents. 8. Natural history of the racer Coluber constrictor. By Henry S. Fitch. Pp. 351-468, pls. 19-22, 20 figures in text. December 30, 1963. $1.00. 9. A review of the frogs of the Hyla bistincta group. By William E. Duellman. Pp. 469-491, 4 figures in text. March 2, 1964. 10. An ecological study of the garter snake, Thamnophis sirtalis. By Henry S. Fitch. Pp. 493-564, pls. 23-25, 14 figures in text. May 17, 1965. 11. Breeding cycle in the ground skink, Lygosoma laterale. By Henry S. Fitch and Harry W. Greene. Pp. 565-575, 3 figures in text. May 17, 1965. 12. Amphibians and reptiles from the Yucatan Peninsula, México. By William E. Duellman. Pp. 577-614, 1 figure in text. June 22, 1965. 13. A new species of turtle, genus Kinosternon, from Central America. By John M. Legler. Pp. 615-625, pls. 26-28, 2 figures in text. June 20, 1965. 14. A biogeographic account of the herpetofauna of Michoacán, México. By William E. Duellman. Pp. 627-709, pls. 29-36, 5 figures in text. December 30, 1965. 15. Amphibians and reptiles of Mesa Verde National Park, Colorado. By Charles L. Douglas. Pp. 711-744, pls. 37 and 38, 6 figures in text. March 7, 1966. Index in preparation. Vol. 16. 1. Distribution and taxonomy of mammals of Nebraska. By J. Knox Jones, Jr. Pp. 1-356, plates 1-4, 82 figures in text. October 1, 1964. $3.50. 2. Synopsis of the lagomorphs and rodents of Korea. By J. Knox Jones, Jr., and David H. Johnson. Pp. 357-407. February 12, 1965. 3. Mammals from Isla Cozumel, Mexico, with description of a new species of harvest mouse. By J. Knox Jones, Jr. and Timothy E. Lawlor. Pp. 409-419, 1 figure in text. April 13, 1965. 4. The Yucatan deer mouse, Peromyscus yucatanicus. By Timothy E. Lawlor. Pp. 421-438, 2 figures in text. July 20, 1965. 5. Bats from Gautemala. By J. Knox Jones, Jr. Pp. 439-472. April 18, 1966. More numbers will appear in volume 16. Vol. 17. 1. Localities of fossil vertebrates obtained from the Niobrara Formation (Cretaceous) of Kansas. By David Bardack. Pp. 1-14. January 22, 1965. 2. Chorda tympani branch of the facial nerve in the middle ear of tetrapods. By Richard C. Fox. Pp. 15-21. June 22, 1965. 3. Fishes of the Kansas River System in relation to zoogeography of the Great Plains. By Artie L. Metcalf. Pp. 23-189, 4 figures in text, 51 maps. March 24, 1966. 4. Factors affecting growth and production of channel catfish, Ictalurus punctatus. By Bill A. Simco and Frank B. Cross. Pp. 191-256, 13 figures in text. June 6, 1966. 5. A new species of fringe-limbed tree frog, genus Hyla, from Darién, Panamá. By William E. Duellman. Pp. 257-262, 1 figure in text. June 17, 1966. 6. Taxonomic notes on some Mexican and Central American hylid frogs. By William E. Duellman. Pp. 263-279. June 17, 1966. 7. Neotropical hylid frogs, genus Smilisca. By William E. Duellman and Linda Trueb. Pp. 281-375, pls. 1-12, 17 figures in text. July 14, 1966. More numbers will appear in volume 17. Transcriber's Note With the exception of the corrections listed below and several minor corrections not listed, the text presented is that which appeared in the original printed version. The list of Kansas University publications has been compiled at the end of the article. Typographical Corrections Page Correction ==== ================== 287 cleared => cleaned 292 Data based of => Data based on 298 CNMH => CNHM 299 Acahuitzotla => Acahuizotla 304 cyanostica => cyanosticta 305 Quatemala => Guatemala 307 cyanostica => cyanosticta 313 Matagalapa => Matagalpa 322 Carribean => Caribbean 323 Centralia => Centrali 336 proportionaely => proportionately 346 noticably => noticeably 362 Fouquett => Fouquette 372 CARVALJO => CARVALHO 375 Dumeril => Duméril ii trutles => turtles 
35413	----	UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Volume 15, No. 7, pp. 297-349, pls. 11-18, 7 figs. October 18, 1963 A Review of the Middle American Tree Frogs of the Genus Ptychohyla BY WILLIAM E. DUELLMAN UNIVERSITY OF KANSAS LAWRENCE 1963 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 15, No. 7, pp. 297-349, pls. 11-18, 7 figs. Published October 18, 1963 UNIVERSITY OF KANSAS Lawrence, Kansas PRINTED BY JEAN M. NEIBARGER, STATE PRINTER TOPEKA, KANSAS 1963 [Union Label] 29-6531 A Review of the Middle American Tree Frogs of the Genus Ptychohyla BY WILLIAM E. DUELLMAN CONTENTS PAGE INTRODUCTION 301 Acknowledgments 301 Materials and Methods 302 ANALYSIS OF DATA 303 External Morphology 303 Color and Pattern 307 Osteology 307 Tadpoles 310 Breeding Call 312 SYSTEMATIC ACCOUNTS 314 _Ptychohyla_ Taylor, 1944 314 Key to Adults 315 Key to Tadpoles 315 _Ptychohyla euthysanota_ Group 315 _Ptychohyla euthysanota_ 315 _Ptychohyla euthysanota euthysanota_ (Kellogg) 315 _Ptychohyla euthysanota macrotympanum_ (Tanner) 320 _Ptychohyla leonhardschultzei_ (Ahl) 323 _Ptychohyla spinipollex_ (Schmidt) 327 _Ptychohyla schmidtorum_ Group 331 _Ptychohyla schmidtorum_ 331 _Ptychohyla schmidtorum schmidtorum_ Stuart 331 _Ptychohyla schmidtorum chamulae_ Duellman 334 _Ptychohyla ignicolor_ Duellman 337 DISTRIBUTION AND ECOLOGY 340 Geographic Distribution of the Species 340 Habitat Preference 342 Interspecific Competition 343 Reproduction and Development 344 PHYLOGENY OF PTYCHOHYLA 345 _Ptychohyla_ as a Natural Assemblage 345 Generic Relationships 346 Interspecific Relationships 347 LITERATURE CITED 349 INTRODUCTION Probably no ecological group of hylid frogs (some _Hyla_ plus _Plectrohyla_ and _Ptychohyla_) in Middle America is so poorly known as those species that live in the cloud forests on steep mountain slopes and breed in cascading mountain streams. During the last half of the nineteenth century most of the species of hylids living in the lowlands of southern México and northern Central America were named and described. Despite the extensive collecting by Salvin and Godman, Nelson and Goldman, and the various expeditions of the _Mission Scientifique_, no members of the genus _Ptychohyla_ were obtained until 1927, when in the mountains of El Salvador Ruben A. Stirton found a small tree frog that subsequently was described and named _Hyla euthysanota_ by Kellogg (1928). Until recently frogs of this genus were known from few specimens and in the literature by nearly as many names. Although I first collected _Ptychohyla_ in 1956, it was not until 1960 that special efforts were made to obtain specimens of this genus. The summer of 1960 was spent in southern México and Guatemala, where every accessible stream in the cloud forests was searched for tree frogs, especially _Ptychohyla_ and _Plectrohyla_. Similar, but less extensive, investigations were carried out in 1961 and 1962. The result of this field work is a rather large collection of _Ptychohyla_ representing all of the known species, plus tape recordings of the breeding calls and tadpoles of all of the species. Previously, I have discussed the nomenclature of one of the species (Duellman, 1960) and have described two new species (Duellman, 1961). In the latter paper I made reference to a future account (this one) that would deal with the systematics and biology of the entire genus. Although I have series of specimens, tadpoles, osteological preparations, and recordings of breeding calls, thereby having a wide array of data at my disposal, much still remains to be learned about these frogs, especially about various aspects of their life histories. Even the validity of the genus is open to question; this problem is discussed at length in the section beyond entitled "_Ptychohyla_ as a Natural Assemblage." Acknowledgments I am indebted to the following persons for permitting me to examine specimens in their care: Miguel Alvarez del Toro, Museo Zoología de Tuxtla Gutierrez, México (MZTG); Charles M. Bogert and Richard G. Zweifel, American Museum of Natural History (AMNH); Doris M. Cochran, United States National Museum (USNM); Norman Hartweg and Charles F. Walker, University of Michigan Museum of Zoology (UMMZ); Robert F. Inger, Chicago Natural History Museum (CNHM); Hobart M. Smith, University of Illinois Museum of Natural History (UIMNH); Heinz Wermuth, Zoologisches Museum Berlin (ZMB); and Ernest E. Williams, Museum of Comparative Zoology (MCZ). The abbreviations following names of institutions will be used throughout the text; the Museum of Natural History at the University of Kansas is abbreviated KU. Throughout my work on these frogs I have profited from discussions with L. C. Stuart, who has made many valuable suggestions and with his characteristic generosity has placed at my disposal his extensive collections of tadpoles from Guatemala. For his aid I am indeed grateful. I am grateful to Thomas E. Moore for tapes of breeding calls of two species. My own field work was made more enjoyable and profitable through the assistance of Dale L. Hoyt, Craig E. Nelson, Jerome B. Tulecke, and John Wellman, all of whom spent many hours in often unsuccessful attempts to collect specimens and record breeding calls of _Ptychohyla_. I am indebted to many residents of México, Guatemala, and El Salvador for permission to work on their land and for providing shelter, food, and guides. I am especially grateful to Mr. and Mrs. Horatio Kelly of "Colegio Linda Vista" at Pueblo Nuevo Solistahuacán, Chiapas, for a pleasant stay at their school; Jordi Juliá Z. of the Comisión del Papaloapan, Ciudad Alemán, Veracruz, for arranging for field work in northern Oaxaca in 1959; Walter Hannstein and Lothar Menzel for the use of facilities at Finca La Paz, Guatemala, in 1960; Alan Hempstead for the use of facilities at Finca Los Alpes, Guatemala in 1960 and 1961; and Julio Aguirre C. of the Instituto Tropical de Investigaciones Científicas, San Salvador, El Salvador, for providing comfortable working quarters and transportation and guides to the mountains in northern El Salvador. Without the cheerful efforts of Jorge A. Ibarra, Director of the Museo Nacional de Historia Natural in Guatemala, my field work would have been greatly restricted during politically precarious times in that country. Permits to collect in México were furnished by the late Luis Macías Arellano of the Dirección General de Caza. Each of these individuals has my profound thanks for his indispensable aid. Field work on hylid frogs in Middle America has been supported by the National Science Foundation, Grant NSF-G9827, and this is the 9th publication on the results of study of the material from America. Materials and Methods During the course of this study I have examined 247 frogs that I assign to the genus _Ptychohyla_, plus 40 lots of tadpoles and 12 skeletal preparations. Furthermore, I have examined all of the type specimens. I have studied each of the species and subspecies in the field and have examined from seven (_P. euthysanota macrotympanum_) to 33 (_P. spinipollex_) living individuals of each species. Measurements given in the analysis of data and in the descriptions of the species are those described by Duellman (1956). In the descriptions of living colors the capitalized names are from Ridgway (1912). All interpretations of osteological characters are based on specimens cleared in potassium hydroxide and stained with alizarin red. Recordings of the breeding calls were made with a Magnemite Portable Tape-recorder; audiospectrographs were made on a vibralyzer (Kay Electric Company) using normal pattern and wide bandwidth. ANALYSIS OF DATA Data that are used to arrive at a systematic arrangement of the species of _Ptychohyla_ are analyzed and discussed below for the values inherent in the analysis. These data are of some value also in the recognition of species and subspecies but if employed for that purpose the data must be used in combination with the keys and the diagnoses of the individual species and subspecies. External Morphology Each of the external morphological characters used in the systematic treatment of _Ptychohyla_, as well as the nature of the tongue, is discussed below. SIZE AND PROPORTIONS.--Comparisons of size and certain proportions are given in Table 1. Frogs of this genus are small; the largest specimen examined is a female of _P. euthysanota euthysanota_ having a snout-vent length of 53.3 mm. The species comprising the _Ptychohyla schmidtorum_ group are smaller; the largest specimen examined is a female of _P. schmidtorum schmidtorum_ having a snout-vent length of 38.0 mm. An analysis of the various measurements and proportions shows few constant differences. _Ptychohyla ignicolor_ differs from all of the other species in having the head slightly wider than long and the tympanum noticeably less than half the size of eye. _Ptychohyla spinipollex_ has a relatively narrow interorbital distance, approximately equal to the width of the eyelid, whereas in all of the other species that distance is much more than the width of the eyelid. SNOUT.--All species have a blunt snout. In _P. leonhardschultzei_ and _P. ignicolor_ the snout is nearly square in lateral profile; in _P. schmidtorum_ the snout is slightly rounded above and below, and in the other species it is rounded above. _Ptychohyla leonhardschultzei_ and _P. spinipollex_ have a vertical fleshy rostral keel on the snout; in these species, because of this keel, the snout in dorsal profile is pointed. The nostrils are slightly protuberant in all species, and in _P. schmidtorum_ the internarial region is slightly depressed. HAND.--The species in the _Ptychohyla euthysanota_ group have a vestige of web between the first and second fingers; the other fingers are about one-third webbed. Breeding males have a cluster of horny nuptial spines on the thumb. The spines are largest in _P. spinipollex_ (Fig. 1) and vary in number from 35 to 66 (average 47.4) on each thumb. In the other species of the _Ptychohyla euthysanota_ group the spines are smaller and usually more numerous; the numbers of spines on each thumb (means in parentheses) in members of this group are: _P. euthysanota euthysanota_, 44-143 (83.8); _P. euthysanota macrotympanum_, 40-110 (63.0); _P. leonhardschultzei_, 24-80 (54.7). The species in the _Ptychohyla schmidtorum_ group have no web between the first and second fingers and only a vestige of web between the other fingers. Furthermore, these species lack nuptial spines in breeding males. Like the usual horny excrescences on the thumbs of many species of frogs, the horny spines on the thumbs of members of the _Ptychohyla euthysanota_ group are seasonal in development. TABLE 1.--VARIATION IN CERTAIN CHARACTERS IN THE SPECIES OF PTYCHOHYLA. (MEANS ARE IN PARENTHESES BELOW THE RANGES.) Key to Table Columns A) Number of specimens B) Maximum snout-vent length C) Tibia length/Snout-vent length D) Tympanum/Eye E) Vomerine teeth ==================+========+======+=======+=========+=========+======= Species | Sex | A | B | C | D | E ------------------+--------+------+-----------------+----------------- | | | | | | _P. euthysanota | [Male] | 17 | 38.1 |44.4-55.0|48.6-63.8| 4-6 euthysanota_ | | | | (48.7) | (56.3) | (5.1) | | | | | | |[Female]| 15 | 53.3 |46.5-56.6|42.9-56.4| 6-18 | | | | (51.4) | (51.4) | (9.6) | | | | | | _P. euthysanota | [Male] | 5 | 38.0 |48.8-52.0|50.0-57.1| 0-4 macrotympanum_| | | | (50.2) | (54.1) | (2.6) | | | | | | |[Female]| 5 | 44.8 |46.4-54.1|48.7-58.9| 8-10 | | | | (50.2) | (53.7) | (9.2) | | | | | | _P. leonhard | [Male] | 16 | 35.6 |48.8-56.1|48.7-61.9| 6-9 schultzei_ | | | | (51.2) | (52.1) | (6.5) | | | | | | |[Female]| 3 | 41.6 |52.3-59.5|47.5-48.6| 7-12 | | | | (54.7) | (48.1) | (9.5) | | | | | | _P. spinipollex_ | [Male] | 32 | 41.2 |46.9-53.1|45.0-55.2| 3-7 | | | | (49.0) | (49.5) | (4.9) | | | | | | |[Female]| 6 | 44.6 |46.1-50.2|47.7-53.8| 6-10 | | | | (48.8) | (50.4) | (7.6) | | | | | | _P. schmidtorum | [Male] | 25 | 32.8 |45.3-52.4|51.5-59.3| 5-11 schmidtorum_ | | | | (48.1) | (54.7) | (6.2) | | | | | | |[Female]| 9 | 38.0 |46.5-49.1|51.3-58.3| 7-11 | | | | (47.7) | (54.9) | (8.7) | | | | | | _P. schmidtorum | [Male] | 40 | 30.5 |46.0-51.9|48.2-65.6| 4-6 chamulae_ | | | | (48.2) | (54.9) | (4.7) | | | | | | |[Female]| 4 | 31.8 |48.1-52.4|51.4-61.7| 4-9 | | | | (50.5) | (55.7) | (6.2) | | | | | | _P. ignicolor_ | [Male] | 13 | 30.5 |45.9-52.2|37.1-47.1| 3-9 | | | | (49.6) | (43.2) | (6.1) ------------------+--------+------+-------+---------+---------+------- [Illustration: FIG. 1. Palmar views of right hands of (A) _Ptychohyla spinipollex_ (KU 58054) and (B) _Ptychohyla schmidtorum schmidtorum_ (KU 58043).] Many workers have used the presence of a bifid subarticular tubercle beneath the fourth finger as a diagnostic character of certain species of hylids. Examination of the subarticular tubercles in _Ptychohyla_ reveals considerable intraspecific variation. Bifid tubercles beneath the fourth finger are found in all species except _P. ignicolor_, which is known from only two specimens. In _P. euthysanota euthysanota_ nearly 60 per cent and in _P. schmidtorum schmidtorum_ about 90 per cent of the specimens have a bifid tubercle beneath the fourth finger on one or both hands. All specimens of _P. leonhardschultzei_ have either a bifid or double tubercle beneath the fourth finger, and some have a bifid distal tubercle beneath the third finger. FEET.--Members of the _Ptychohyla euthysanota_ group have a weak tarsal fold, whereas in the species comprising the _Ptychohyla schmidtorum_ group the tarsal fold is absent. Webbing on the foot extends to the discs of the third and fifth toes and to the base of the penultimate phalanx of the fourth toe, except in _P. ignicolor_, which has less webbing. VENTROLATERAL GLANDS.--Breeding males develop thickened, pigmented glandular areas on the sides of the body. In living specimens of _P. schmidtorum_ and _P. ignicolor_ the glands are not readily visible, but in preservative they show as distinctive orange-colored areas. These glands are most distinct in _P. euthysanota_; in many specimens of this species the glands are elevated above the surrounding skin. The extent of the glands is variable (Fig. 2); probably this variability is due to different degrees of development in individual frogs rather than to interspecific differences. All _Ptychohyla ignicolor_ and some _P. schmidtorum chamulae_ have a small, round glandular area on the chin; to my knowledge this does not occur in the other species. Superficial examination of microscopic preparations of the glands reveals no histological differences between species. The glands occupy most of the thickened area and have narrow ducts leading to the exterior. Detailed studies of the histology will be reported elsewhere. Since the glands are developed only in breeding males, it is surmised that the glands are associated with some phase of the breeding activity. [Illustration: FIG. 2. Normal extent of ventrolateral glands in (A) _Ptychohyla euthysanota euthysanota_ (KU 58008), (B) _Ptychohyla schmidtorum schmidtorum_ (KU 58037), and (C) _Ptychohyla ignicolor_ (UMMZ 119603).] TONGUE.--The shape of the tongue varies intraspecifically. Usually the tongue is ovoid; in some specimens it is barely notched posteriorly, whereas in others it is deeply notched, making the tongue cordiform. Deeply notched cordiform tongues are found in _P. leonhardschultzei_ and _P. schmidtorum_; with the exception of these two species, some individuals of all species have emarginate tongues. Some individuals of all species have tongues that are shallowly notched posteriorly. Color and Pattern The dorsum in living frogs of the genus _Ptychohyla_ is primarily yellowish or reddish brown, except in _P. schmidtorum chamulae_ and _P. ignicolor_ in which it is green. Usually there are some darker blotches or reticulations on the dorsum. The venter usually is white; in _P. ignicolor_ it is yellow. The venter is spotted in all members of the _Ptychohyla euthysanota_ group; the species, arranged from least to most spotting ventrally, are: _P. euthysanota euthysanota_, _P. euthysanota macrotympanum_, _P. leonhardschultzei_, and _P. spinipollex_. The last two species also have bold dark spots on the flanks. _Ptychohyla schmidtorum_ lacks spots on the venter, whereas _P. ignicolor_ has small dark flecks ventrally. _Ptychohyla euthysanota_ and _P. schmidtorum_ have white stripes on the upper lips and on the flanks. All species have some form of a pale stripe above the anus and usually rather distinct white or pale stripes along the ventrolateral edges of the tarsi and forearms. There are no bright or boldly marked flash-colors (colors that are revealed only when the hind limbs are extended), except in _P. ignicolor_, which has bright red flash-colors in the groin and on the thighs. In life the iris varies from several different shades of bronze color to deep red in _P. schmidtorum schmidtorum_. The degree of metachrosis is moderate. Usually any change of color in life consists only of change in the intensity of color. At times when the over-all coloration is darkened some markings are obscured. Osteology The following description of the skull, hyoid, sternum, and prepollex is based on a male specimen of _P. spinipollex_ (KU 68632) that has been cleared and stained. The broad, flat skull (Fig. 3) has a large frontoparietal fontanelle. The ethmoid is large and has a flange laterally. The nasals are of moderate size and in broad contact with the ethmoid, but are separated from one another medially. The anterior half of the maxillary bears a thin, high flange. The anterior process of the squamosal is short and widely separated from the maxillary. The quadratojugal is a small spine-shaped element projecting anteriorly from the ventral base of the quadrate; the quadratojugal does not articulate with the maxillary. [Illustration: FIG. 3. Dorsal aspect of skull of _Ptychohyla spinipollex_ (KU 68632). Arrow indicates reduced quadratojugal.] The posteromedian part of the hyoid plate is calcified; from this plate the long bony, posterior cornua (thyrohyales) extend posterolaterally. The omosternum is calcified, widest anteriorly, and has a convex anterior edge. The calcified xiphisternum is roughly bell-shaped having short lateral processes anteriorly and a deep notch posteriorly. The swollen thumb is supported by a dorsoventrally flattened spine that does not extrude through the skin. VARIATION.--In general, the skull varies little. Usually the quadratojugal is present only as a short element attached to the quadrate, but in one specimen of _P. spinipollex_ the quadratojugal articulates with the maxillary and forms a complete quadratojugal-maxillary arch on each side of the skull. One specimen of _P. leonhardschultzei_ has a complete arch on one side and an incomplete arch on the other. Only _P. spinipollex_ has lateral processes anteriorly on the xiphisternum; in the other species the xiphisternum is deeply bell-shaped. _Ptychohyla schmidtorum_ and _P. ignicolor_ have slightly longer premaxillaries than the other species. The longer premaxillary is reflected in the larger number of teeth on the bone--9 to 11 (average 10) in four specimens of _P. schmidtorum_ and 10 teeth in one _P. ignicolor_, as compared with 6 to 10 (average 7.9) in seven specimens of the other species. The number of maxillary teeth in the various species are: _P. euthysanota euthysanota_, 43; _P. euthysanota macrotympanum_, 38; _P. leonhardschultzei_, 38 and 40; _P. spinipollex_, 34 and 40; _P. schmidtorum schmidtorum_, 37 and 43; _P. schmidtorum chamulae_, 40 and 41; _P. ignicolor_, 43. The teeth on the premaxillary and anterior part of the maxillary are long, pointed, and terminally curved backwards. Posteriorly on the maxillary the teeth become progressively shorter and blunter. Variation in number of vomerine teeth is shown in Table 1. [Illustration: FIG. 4. Tadpoles of the _Ptychohyla euthysanota_ group: (A) _P. euthysanota euthysanota_ (KU 60042), (B) _P. euthysanota macrotympanum_ (KU 60049), (C) _P. leonhardschultzei_ (KU 68556), and (D) _P. spinipollex_ (KU 60053).] Tadpoles Tadpoles of the genus _Ptychohyla_ are adapted to live in mountain streams. The bodies are streamlined, and the tails are long and have low fins (Figs. 4 and 5). The mouths are large and directed ventrally. Tadpoles of the two groups of species have strikingly different mouthparts. [Illustration: FIG. 5. Tadpoles of (A) _Ptychohyla schmidtorum schmidtorum_ (KU 60051), (B) _P. schmidtorum chamulae_ (KU 58199), and (C) _P. ignicolor_ (KU 71716).] Lips of tadpoles of the _Ptychohyla euthysanota_ group (Fig. 6 A-D) are folded laterally; there are 4/6 or sometimes 4/7 tooth-rows. A lateral "wing" projects on either side of the upper beak. The beaks have blunt, peglike serrations. Lips of tadpoles of the _Ptychohyla schmidtorum_ group (Fig. 6 E-G) are greatly expanded and form a funnel-shaped disc; there are 3/3 short tooth-rows. There is no lateral projection or "wing" on either side of the upper beak. The beaks have long, pointed serrations. [Illustration: FIG. 6. Mouthparts of tadpoles of _Ptychohyla_: (A) _P. euthysanota euthysanota_ (KU 60042), (B) _P. euthysanota macrotympanum_ (KU 60049), (C) _P. leonhardschultzei_ (KU 68556), (D) _P. spinipollex_ (KU 60053), (E) _P. schmidtorum schmidtorum_ (KU60051), (F) _P. schmidtorum chamulae_ (KU 58199), and (G) _P. ignicolor_ (KU 71716). × 10.] Variation in certain structural details and in coloration is discussed for each species and subspecies in the systematic accounts that follow. Sizes, proportions, and numbers of tooth-rows are tabulated in Table 2. TABLE 2.--COMPARISON OF CERTAIN LARVAL CHARACTERS IN THE SPECIES OF PTYCHOHYLA. (MEANS ARE IN PARENTHESES BELOW THE RANGES.) ==============================+=========+=======+============+========== | Number |Maximum| Head length| Species | of | total |------------|Tooth-rows |specimens| length|Total length| ------------------------------+---------+-------+------------+---------- _P. euthysanota euthysanota_ | 23 | 40.8 | 30.9-37.3 | 4/6 | | | (33.5) | _P. euthysanota macrotympanum_| 13 | 43.3 | 30.6-33.4 | 4/6 | | | (32.7) | _P. leonhardschultzei_ | 7 | 47.5 | 29.2-32.7 | 4/6 | | | (31.1) | _P. spinipollex_ | 32 | 45.0 | 30.2-35.9 | 4/7 | | | (33.0) | _P. schmidtorum schmidtorum_ | 14 | 42.5 | 28.9-31.2 | 3/3 | | | (29.9) | _P. schmidtorum chamulae_ | 4 | 45.0 | 26.9-29.3 | 3/3 | | | (27.8) | _P. ignicolor_ | 2 | 39.6 | 29.6-29.8 | 3/3 | | | (29.7) | ------------------------------+---------+-------+------------+---------- Evidence on the pattern of development of tooth-rows indicates that the inner rows develop first. A small tadpole of _P. euthysanota euthysanota_ has six lower rows and three fully developed upper rows and only the beginning of the first (outer) upper row. A small tadpole of _P. euthysanota macrotympanum_ has four upper rows and five lower rows. In a small tadpole of _P. leonhardschultzei_ the three upper and four lower tooth-rows are well developed; the first upper and fifth lower rows are beginning to develop, and the sixth lower row is absent. In small tadpoles of _P. spinipollex_, the sixth lower row is poorly developed, and the seventh row is absent; large individuals normally have seven lower rows. A small tadpole of _P. schmidtorum chamulae_ has 3/2 tooth-rows. Breeding Call Breeding calls of all species and subspecies of _Ptychohyla_ were recorded in the field. Obtaining series of calls of _Ptychohyla_ is difficult because these frogs call mostly from vegetation along roaring mountain streams and only by locating a calling frog some distance from the water or along a quiet stretch of the stream can good recordings be obtained. For example, four individuals of _P. spinipollex_ were recorded, but only one recording was sufficiently free of background noise to be analyzed. Analysis of breeding calls supports the division of the genus _Ptychohyla_ into two groups of species. The call of each member of the _Ptychohyla euthysanota_ group consists of a single long note, whereas the call of species in the _Ptychohyla schmidtorum_ group consists of a series of short notes. Since no differences were found between the calls of subspecies of any given species, the following discussion of breeding calls pertains to species. These calls are described briefly below and at greater length in the systematic accounts farther on. Audiospectrographs of the breeding calls are shown in Plate 11, and comparisons of the characteristics of the calls are given in Table 3. [Illustration: PLATE 11 Audiospectrographs of the breeding calls of the five species of _Ptychohyla_: (A) _P. spinipollex_ (KU Tape No. 41), (B) _P. euthysanota macrotympanum_ (KU Tape No. 48), (C) _P. leonhardschultzei_ (UMMZ Tape No. 525), (D) _P. schmidtorum chamulae_ (KU Tape No. 52), (E) _P. ignicolor_ (UMMZ Tape No. 526).] TABLE 3.--COMPARISON OF THE BREEDING CALLS OF PTYCHOHYLA -------------------------------------------------------------------------- ----------------+----+--------+-----------+---------+---------+----------- | | Notes | Duration | Pulses |Frequency| Dominant Species |Num-|per call| of note | per | range | frequency | ber| group | (seconds) | second | (cps) | (cps) ----------------+----+--------+-----------+---------+---------+----------- _P. spinipollex_| 1 | 1 | .46 | 147 |3000-5100| 4300 | | | | | | _P. euthysanota_| 7 | 1 | .62 | 95.3 |1800-4200| 3070 | | | (.60-.65) | (91-102)| |(3000-3200) | | | | | | _P. leonhard- | 2 | 1 | .79 | 77 |1500-3500| 2750 schultzei_| | | (.62-.95) | (76-78) | |(2700-2800) | | | | | | _P. schmidtorum_| 6 | 8.5[A] | .064 | 110 |1400-5800| 3400 | | (8-9) |(.054-.070)| (96-121)| |(3350-3450) | | | | | | _P. ignicolor_ | 2 | 12[A] | .079 | 126 |1000-5000| 3150 | |(11-13) |(.078-.080)|(123-129)| |(3100-3200) ----------------+----+--------+-----------+---------+---------+----------- [Footnote A: Only an analysis of the long series of calls is given here; see text for explanation.] _P. spinipollex_ (Pl. 11A).--One long note is repeated at intervals of 45 seconds to four minutes and has an average dominant frequency of 4300 cycles per second. _P. euthysanota_ (Pl. 11B).--One long note is repeated six to nine times at intervals of 2.7 to 3.4 seconds and has an average dominant frequency of 3070 cycles per second. _P. leonhardschultzei_ (Pl. 11C).--One long note is repeated once after 10 to 13 seconds and has an average dominant frequency of 2750 cycles per second. _P. schmidtorum_ (Pl. 11D).--The complete call consists of one short series of notes alternating with two long series. Numbers of notes per series in one individual having a typical call were 5-8-8-3-9-9. The average dominant frequency of notes in the short and long series alike is 3400 cycles per second. _P. ignicolor_ (Pl. 11E).--The complete call consists of a short series of notes alternating with a long series. In one complete recording the numbers of notes in these series were 4-13-3-11. The notes in the short series have an average dominant frequency of 2100 cycles per second, whereas the notes in the long series have an average dominant frequency of 3150 cycles per second. The four series of notes were given in one minute and 15 seconds. SYSTEMATIC ACCOUNTS The museum catalogue numbers of the specimens examined, together with the localities from which they came, are listed at the end of the account of each subspecies or monotypic species. The localities that are represented by symbols on the distribution map (Fig. 7) are in roman type; those that are not represented on the map, because overlapping of symbols would have occurred, are in italic type. =Ptychohyla= Taylor, 1944 _Ptychohyla_ Taylor, Univ. Kansas Sci. Bull., 30:41, May 15, 1944. Type, _Ptychohyla adipoventris_ Taylor, 1944 [= _Hyla leonhardschultzei_ (Ahl), 1934]. _Diagnosis._--Small hylids having stream-adapted tadpoles and differing from other hylid genera in having large ventrolateral glands in breeding males. _Composition._--Five species, two of which are made up of two subspecies, arranged in two groups of species on the basis of morphological characters of adults and tadpoles and on the basis of breeding calls. _Distribution._--Moderate elevations from southern Guerrero and northern Oaxaca, México, to northern El Salvador and central Honduras. KEY TO ADULTS 1. A weak tarsal fold; outer fingers one-third webbed; males having spiny nuptial tuberosities; color in life tan or brown with blotches or reticulations, never green; iris bronze color _P. euthysanota_ group--2 No tarsal fold; outer fingers having only vestige of web; males lacking nuptial tuberosities; color in life green or brown; iris red or golden color _P. schmidtorum_ group--5 2. Chest, throat, and flanks usually having brown or black spots; no distinct white stripe on upper lip or on flanks; a faint white line usually present above anal opening; a rostral keel 3 Chest, throat, and flanks usually unspotted; distinct white line on upper lip and on flank present or not; white line above anal opening faint or well defined; no rostral keel 4 3. Interorbital region much wider than eyelid; spots on throat and chest black; spots only occasionally present on belly; flanks marbled with black and white; nuptial spines small, as many as 80 on one thumb _P. leonhardschultzei_ Interorbital region about as wide as eyelid; spots on chest and throat brown or black; spots usually present on belly; flanks having round brown or black spots; nuptial spines moderate in size, conical, seldom more than 60 on one thumb _P. spinipollex_ 4. A distinct, broad, white lateral stripe usually present; usually a distinct white line above anal opening; a distinct white stripe on upper lip _P. euthysanota euthysanota_ No white lateral stripe; a faint white stripe above anal opening; no distinct white stripe on upper lip _P. euthysanota macrotympanum_ 5. A distinct, broad, lateral stripe; a white stripe on upper lip expanded to form a large spot below eye; hidden surfaces of thighs and webs of feet not red in life; internarial region slightly depressed; diameter of tympanum greater than one-half diameter of eye 6 No lateral white stripe; no stripe on upper lip; in life dorsum green, hidden surfaces of thighs and webs of feet orange tan to bright red, and eye golden color; internarial region flat; diameter of tympanum less than one-half diameter of eye _P. ignicolor_ 6. Webs of feet and posterior surfaces of thighs pale cream color; dorsum in life reddish brown; iris bright red _P. schmidtorum schmidtorum_ Webs of feet and posterior surfaces of thighs pale brown; dorsum in life green; iris reddish bronze color _P. schmidtorum chamulae_ KEY TO TADPOLES 1. Lips greatly expanded forming a funnel-shaped mouth; tooth-rows 3/3 _P. schmidtorum_ group--2 Lips folded laterally, not forming a funnel-shaped mouth; tooth-rows 4/6 or more _P. euthysanota_ group--4 2. Belly and mouth mottled; tail cream color heavily blotched with brown 3 Belly dark gray; tail cream color with dense brown flecking, giving brown appearance _P. schmidtorum chamulae_ 3. Belly cream color with brown mottling; no large tubercle at each end of first lower tooth-row _P. schmidtorum schmidtorum_ Belly grayish green with brown mottling; a large tubercle at each end of first lower tooth-row _P. ignicolor_ 4. Tooth-rows 4/6; cream-colored crescent-shaped mark on posterior part of body bordered posteriorly by large brown mark 5 Tooth-rows usually 4/7 (sometimes 4/6); cream-colored crescent-shaped mark on posterior part of body usually indistinct, not bordered posteriorly by large brown mark _P. spinipollex_ 5. Caudal musculature uniformly flecked with brown; lower tooth-rows 1-4 about equal in length to upper rows _P. euthysanota euthysanota_ Caudal musculature having brown square blotches dorsally on anterior one-half of tail; lower tooth-rows 1-4 usually slightly shorter than upper rows 6 6. Dorsal caudal blotches well defined and extending onto sides of tail; moderately large brown flecks on caudal fin; eye in life pale reddish brown _P. leonhardschultzei_ Dorsal caudal blotches faint, not extending onto sides of tail; small brown flecks on caudal fin; eye in life silvery bronze _P. euthysanota macrotympanum_ The _Ptychohyla euthysanota_ Group Three species in group; adults having moderate amount of webbing between fingers, and tarsal fold; breeding males having spinous, horny, nuptial tuberosities on pollex; mouths of tadpoles having lateral folds in lips and 4/6 or 4/7 tooth-rows; breeding call consisting of one long note. =Ptychohyla euthysanota= _Diagnosis._--Rostral keel absent; nuptial spines in males small; interorbital region much wider than eyelid. [Illustration: PLATE 12 _Ptychohyla euthysanota euthysanota_ (KU 58008). × 2.] =Ptychohyla euthysanota euthysanota= (Kellogg) _Hyla euthysanota_ Kellogg, Proc. Biol. Soc. Washington, 41:123-124, June 29, 1928 [Holotype.--USNM 73296 from Los Esemiles, Depto. Chalatenango, El Salvador; Ruben A. Stirton collector]. Mertens, Senckenbergiana, 33:169-171, June 15, 1952; Abhand. Senckenbergische Naturf. Gesell., 487:29, December 1, 1952. Stuart, Proc. Biol. Soc. Washington, 67:169, August 5, 1954. _Hyla rozellae_ Taylor, Univ. Kansas Sci. Bull., 28:78-80, pl. 9, fig. 1, May 15, 1942 [Holotype.--USNM 115039 from Salto de Agua, Chiapas, México; Hobart M. and Rozella Smith collectors]. Taylor and Smith, Proc. U. S. Natl. Mus., 95:587, June 30, 1945. Smith and Taylor, Bull. U. S. Natl. Mus., 194:86, June 17, 1948. Stuart, Proc. Biol. Soc. Washington, 67:169, August 5, 1954. _Ptychohyla bogerti_ Taylor, Amer. Mus. Novitates, 1437:13-16, fig. 5, December 7, 1949 [Holotype.--AMNH 51847 from Río Grande, Oaxaca, México; Thomas MacDougall collector]. Stuart, Proc. Biol. Soc. Washington, 67:169, August 5, 1954. _Ptychohyla euthysanota_, Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 13:351, April 27, 1961. _Diagnosis._--Dorsum tan to reddish brown; venter white; rarely flecked with brown or black; a white stripe on upper lip, on flank, and usually above anus. _Description._--The following description is based on KU 58008 from Finca La Paz, Depto. San Marcos, Guatemala (Pl. 12). Adult male having a snout-vent length of 35.0 mm.; tibia length, 16.5 mm.; tibia length/snout-vent length, 47.1 per cent; foot length, 14.2 mm.; head length, 11.0 mm.; head length/snout-vent length, 31.4 per cent; head width, 10.7 mm.; head width/snout-vent length, 30.6 per cent; diameter of eye, 3.3 mm.; diameter of tympanum, 1.8 mm.; tympanum/eye, 54.5 per cent. Snout in lateral profile nearly square, slightly rounded above, and in dorsal profile bluntly rounded; canthus pronounced; loreal region moderately concave; lips thick, rounded, and slightly flaring; nostrils protuberant; internarial distance, 3.0 mm.; top of head flat; interorbital distance, 4.1 mm., and approximately a third broader than width of eyelid, 2.9 mm. Moderately heavy dermal fold from posterior corner of eye above tympanum to point above insertion of forelimb, covering upper edge of tympanum; tympanum round, its diameter slightly more than its distance from eye. Forearm moderately robust, having distinct dermal fold on wrist; dermal fold, but no row of tubercles along ventrolateral surface of forearm; pollex only slightly enlarged, bearing triangular shaped patch of small horn-covered spines (128 on right, 134 on left); second and fourth fingers equal in length; subarticular tubercles round, distal one on fourth finger bifid; discs moderate in size, that of third finger equal to diameter of tympanum; no web between first and second fingers; other fingers one-third webbed. Heels broadly overlap when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; low rounded tarsal fold; inner metatarsal tubercle large, elliptical, and flat; outer metatarsal tubercle small and round; low dermal fold from heel to disc of fifth toe; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third and fifth toes webbed to base of disc; fourth toe webbed to proximal end of penultimate phalanx; thin dermal fold from inner metatarsal tubercle to disc of first toe; disc smaller than on fingers. Anal opening at the level of the upper edge of thighs; anal flap short; anal opening bordered above by thin transverse dermal fold and laterally by heavy dermal fold. Skin of dorsum and ventral surfaces of forelimbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands moderately developed, not reaching axilla or groin and broadly separated midventrally. Tongue ovoid, emarginate, and only slightly free posteriorly; vomerine teeth 2-2, situated on small triangular elevations between ovoid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus. Dorsal ground-color of head, body, and limbs dull reddish brown with irregular dark brown reticulations on head and body and dark brown transverse bands on limbs; dorsal surfaces of first and second fingers and webbing on hand cream color; dorsal surfaces of third and fourth fingers dull brown; anterior surfaces of thighs dull creamy yellow; posterior surfaces of thighs dull brown; tarsi and toes tan with brown flecks; webbing of feet brown; faint creamy white stripe along lateral edges of tarsi and forearms; thin white line along edge of upper lip; distinct white stripe above and beside anal opening; axilla white; throat, chest, belly, and ventral surfaces of forelimbs creamy white; flanks white, separated from pale venter by a row of partly connected dark brown spots; ventral surfaces of thighs dull creamy yellow; feet grayish brown; ventrolateral glands pale grayish brown; small brown flecks on periphery of chin. In life the dorsal ground-color was pale reddish brown (Orange-Cinnamon); dorsal reticulations dark brown (Chocolate); dorsal surfaces of first and second fingers and webbing on hands creamy tan (Light Pinkish Cinnamon); posterior surfaces of thighs reddish brown (Vinaceous-Tawny); webbing of feet gray (Deep Mouse Gray); throat and belly grayish white (Pale Gull Gray); ventral surfaces of hind limbs creamy white (Marguerite Yellow); spots on flanks dark brown (Warm Sepia); iris reddish bronze (Apricot Orange). _Variation._--No geographic variation in structural characters is discernible; variation in size and proportions is given in Table 1. Of 32 adults examined, seven have the tongue shallowly notched posteriorly; in the others the tongue is emarginate. Twenty specimens have a bifid subarticular tubercle beneath the fourth finger; in the others there are no bifid tubercles. The coloration described above is typical of the 16 specimens available from Finca La Paz. The living coloration at night, when the frogs were collected, was somewhat darker than the living colors described above, which were recorded for the frogs the morning after collection, at which time one individual had a pale reddish brown dorsum (Orange-Cinnamon) with dull olive green (Deep Grape Green) reticulations on the back and transverse bands on the limbs; the dorsal surfaces of the first and second fingers and the discs on the third and fourth fingers were orange (Mikado Orange). More than half of the specimens from Finca La Paz agree in all essential characters with the description given above. The distinctness of the white stripe on the upper lip is variable; in two individuals the stripe is barely discernible. Likewise, in some individuals the white stripe on the flanks is not distinct, either because there are few or no brown spots separating the stripe from the pale venter, or because the ventrolateral gland has diffused the pale color on the flanks. There is some noticeable variation in dorsal coloration, either through a greater or lesser development of dark pigment. One specimen (KU 58007) is grayish tan above with dark brown markings; the posterior surfaces of the thighs are dull grayish yellow; the first and second fingers and the webbing on the hands are pale yellowish gray; the belly and throat are dusty white; the flecks on the throat are gray; the ventral surfaces of the feet are grayish brown. Dark individuals, such as KU 58009 have a uniform dark brownish black dorsum; the belly is cream; the first and second fingers and the webbing on the hands are dull creamy tan; the dorsal and ventral surfaces of the feet are dark brown. In KU 58013 there is a heavy suffusion of brown on the throat and flanks. Two specimens have scattered white flecks on the dorsum. The reddish brown dorsal ground-color with dark brown reticulations on the head and body and dark brown transverse bands on the limbs seems to be rather constant throughout the range of the subspecies. Likewise, the presence of the white stripe on the upper lip and the white stripe around the anal opening are present on most specimens. In breeding males having well-developed ventrolateral glands the lateral white stripe often is obliterated. _Description of Tadpole._--The following description is based on KU 60042 from Finca La Paz, Depto. San Marcos, Guatemala (Figs. 4A and 6A). No limb buds; total length, 35.8 mm.; body length, 11.2 mm.; body length/total length, 31.3 per cent. Body moderately depressed, slightly wider than deep, ovoid in dorsal profile; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils slightly protuberant and directed anteriorly, closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Caudal fin low, rounded posteriorly; depth of caudal musculature about one-half greatest depth of caudal fin; musculature extends nearly to tip of tail. Mouth large; lips having deep lateral folds; two complete rows of papillae on lips; five to six rows of papillae laterally. Beaks moderately developed, bearing peglike serrations; slender lateral projections on upper beak; tooth-rows 4/6; upper rows subequal in length, second longest; fourth row interrupted medially; lower rows complete; lower rows 1-4 equal in length to upper rows; fifth lower row somewhat shorter; sixth lower row short. Body brown above; tip of snout cream color; grayish cream color below; caudal musculature creamy tan; caudal fin transparent; cream-colored crescent-shaped mark on posterior edge of body and anterior part of caudal musculature, bordered posteriorly by dark brown blotch; scattered brown flecks on caudal musculature and posterior part of caudal fin. Eye bronze color in life. _Variation._--The variation in size and proportions is given in Table 2. In some specimens the first upper tooth-row is irregular, sometimes broken, and often shorter than other upper tooth-rows. Usually the fourth upper and first lower, and sometimes the sixth lower, tooth-rows are interrupted medially. One specimen has a short, irregular, seventh lower tooth-row; all others have six. The cream-colored crescent-shaped mark usually is distinct. The brown blotch posterior to this mark is variously shaped ranging from a narrow vertical bar to a triangular blotch. Brown flecks seldom are present on the anterior part of the ventral caudal fin. _Comparisons._--Aside from the characters given in the diagnosis, _P. euthysanota euthysanota_ can be distinguished from both _P. spinipollex_ and _P. leonhardschultzei_ by the absence of bold black and white marbling on the flanks; furthermore, from the former it can be distinguished by having more and smaller horny nuptial spines and from the latter by having the snout, in lateral profile, rounded above and not acutely angulate. _Ptychohyla euthysanota euthysanota_ differs from _P. euthysanota macrotympanum_ by normally having a darker dorsal color, broader stripe on upper lip, and a distinct lateral stripe. Occurring sympatrically with _Ptychohyla euthysanota euthysanota_ are several species of _Plectrohyla_, all of which differ in having a bony prepollex, rather rugose skin on the dorsum, and more squat bodies. Other sympatric species are _Ptychohyla schmidtorum schmidtorum_, which lacks a tarsal fold and nuptial spines and has a red eye in life, _Hyla salvadorensis_, which has a green dorsum and lacks spinous nuptial tuberosities, and _Hyla sumichrasti_, a small yellow frog usually lacking vomerine teeth. _Life History._--This subspecies breeds in clear, swift mountain streams. Males call from stems and leaves of plants at the edge of, or overhanging, the streams. The breeding call consists of a soft "wraack," repeated at intervals of three to four seconds. Each note has a duration of 0.60 to 0.65 seconds and has 91 to 102 pulses per second; the dominant frequency falls between 3000 and 3200 cycles per second. Tadpoles in various stages of development were found at Finca La Paz, Guatemala, in late July. This indicates that there is either extreme differential growth, or, more probably, an extended breeding season. A tadpole having a body length of 6.8 mm. and a total length of 19.1 mm. has a short median first upper tooth-row; lower tooth-rows 3-6 are only two-thirds as long as lower rows 1 and 2. Two recently metamorphosed young have snout-vent lengths of 14.2 and 14.8 mm.; they are colored like the adults. _Remarks._--The type specimen of _Hyla euthysanota_ Kellogg (1928:123) is a female; therefore, when Taylor (1944) proposed the name _Ptychohyla_ for hylids having ventrolateral glands in breeding males, he was unaware that _Hyla euthysanota_ was a member of this group. In his description of _Hyla rozellae_, Taylor (1942) did not compare his specimens with _Hyla euthysanota_, but instead placed _H. rozellae_ with _H. loquax_ and _H. rickardsi_. The type series of _H. rozellae_ consists of one large adult female and several metamorphosing young. Taylor (1949:16) based the description of _Ptychohyla bogerti_ on two males and compared these specimens with _P. adipoventris_ Taylor [= _P. leonhardschultzei_ (Ahl)]. Thus, in a period of 22 years the females of this species were given two names and the male another. Stuart (1954:169) suggested that _Hyla euthysanota_ and _Hyla rozellae_ were _Ptychohyla_. Now that sufficient specimens are available from throughout the range it is possible to determine that the various named populations are conspecific. _Distribution._--This subspecies inhabits cloud forests at elevations of 660 to 2200 meters on the Pacific slopes of the Sierra Madre from extreme eastern Oaxaca and western Chiapas, México, through Guatemala to northern El Salvador; probably it occurs also in southwestern Honduras. Aside from the specimens listed below, three in the Frankfurt Museum from Depto. Santa Ana, El Salvador (44571, Hacienda San José; 43040, Hacienda Los Planes; 65119, Miramundo) are listed by Mertens (1952:29). _Specimens examined._--MEXICO: _Chiapas: Cascarada, 30 km. W of Cíltapec_, UMMZ 87851-2; Cerro Ovando, UMMZ 87853-4; Chicomuselo, UMMZ 94439-40; Finca Juárez, 28 km. N of Escuintla, USNM 115052-5; _Las Nubes, Cerro Ovando_, USNM 115030-8; Salto de Agua, USNM 115039-51. _Oaxaca_: Cerro Pecho Blanco, UIMNH 40963; between La Gloria and Cerro Azul, UIMNH 40976-7; Río Grande, AMNH 51847-8; Santo Tomás Tecpan, UIMNH 41071. GUATEMALA: _San Marcos_: Finca La Paz, 2 km. W of La Reforma, KU 58001-14, 59937 (skeleton), 60042-3 (tadpoles), 60044 (4 young), MCZ 34997, UMMZ 107739, 123151-7 (tadpoles); Finca Pirineos, Río Samalá, CNHM 35066. _Santa Rosa_: Finca La Gloria, UMMZ 123148 (tadpoles), 123150 (tadpoles). _Sololá_: Finca Santo Tomás, UMMZ 123149 (tadpoles); Olas de Mocá, near Mocá, CNHM 20208. EL SALVADOR: _Chalatenango_: Los Esemiles, USNM 73296. _Santa Ana_: Miramundo, CNHM 65120. [Illustration: PLATE 13 _Ptychohyla euthysanota macrotympanum_ (KU 58049). × 2.] =Ptychohyla euthysanota macrotympanum= (Tanner) _Hyla macrotympanum_ Tanner, Great Basin Nat., 17:52-53, July 31, 1957 [Holotype.--AMNH 62141 (formerly BYU 13752) from 10 miles east of Chiapa de Corzo, Chiapas, México; Robert Bohlman collector]. _Ptychohyla macrotympanum_, Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 13:351, April 27, 1961. _Diagnosis._--Dorsum usually pale tan; venter white with scattered brown or black flecks; a thin white stripe on upper lip and another above anal opening; no distinct white stripe on flanks. _Description._--The following description is based on KU 58049 from Linda Vista, Chiapas, México (Pl. 13). Adult male having a snout-vent length of 38.0 mm.; tibia length, 19.5 mm.; tibia length/snout-vent length, 51.3 per cent; foot length, 15.7 mm.; head length, 11.8 mm.; head length/snout-vent length, 31.1 per cent; head width, 11.7 mm.; head width/snout-vent length, 30.8 per cent; diameter of eye, 3.8 mm.; diameter of tympanum, 2.1 mm.; tympanum/eye, 55.2 per cent. Snout in lateral profile nearly square, slightly rounded above, and in dorsal profile bluntly rounded; canthus pronounced; loreal region concave; lips thick, rounded, and slightly flaring; nostrils protuberant; internarial distance, 3.1 mm.; top of head flat; interorbital distance, 3.8 mm., and approximately a fourth broader than width of eyelid, 3.1 mm. A moderately heavy dermal fold from posterior corner of eye above tympanum to point above insertion of forelimb, covering upper edge of tympanum; tympanum round, its diameter equal to its distance from eye. Forearm moderately robust, having a distinct dermal fold on wrist; dermal fold, but no row of tubercles along ventrolateral surface of forearm; pollex only slightly enlarged, bearing triangular patch of small horn covered spines (94 on right, 100 on left); fourth finger slightly longer than second; subarticular tubercles round, none bifid; discs moderate in size, that of third finger equal to diameter of tympanum; vestige of web between first and second fingers; other fingers one-third webbed. Heels broadly overlap when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; weak tarsal fold on distal two-thirds of tarsus; inner metatarsal tubercle large, elliptical, and flat; outer metatarsal tubercle small and round; no dermal fold from heel to disc of fifth toe; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third toe webbed to base of disc; fifth toe webbed to middle of penultimate phalanx; fourth toe webbed to proximal end of penultimate phalanx; no fold of skin from inner metatarsal tubercle to base of disc on first toe; discs much smaller than on fingers. Anal opening near upper edge of thighs; short anal flap bordered above by thin dermal fold; small tubercles and heavy dermal fold lateral to anal opening. Skin of dorsum and ventral surfaces of fore limbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands weakly developed, not reaching axilla or groin and broadly separated midventrally. Tongue ovoid, shallowly notched posteriorly, and barely free behind; vomerine teeth 2-2, situated on small triangular elevations between ovoid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus. Dorsal ground-color of head, body, and limbs pale pinkish tan with the greatest part of head and body covered by large gray interconnected blotches; black flecks over most of dorsum; grayish brown transverse bands on shanks; dorsal surfaces of first and second fingers pale grayish yellow; dorsal surfaces of third and fourth fingers and webbing on hand pale grayish tan; anterior surfaces of thighs pale flesh-color; posterior surfaces of thighs pale grayish yellow; dorsal surfaces of tarsi and toes pale grayish tan with black flecks; webbing of feet pale gray; faint creamy white stripes along ventrolateral edges of tarsi and forearms; a very thin white line along edge of upper lip; a narrow grayish white stripe above anal opening; axilla gray; throat, chest, belly, and ventral surfaces of forelimbs pale grayish white; ventral surfaces of hind limbs cream color; flanks gray flecked with brown; ventral surfaces of feet grayish tan; ventrolateral glands pinkish tan; anterior one-half of chin flecked with brown. In life the dorsum was pale tan (Pinkish Buff); the dark markings on dorsum dull brown (Tawny-Olive); tarsi pale tan (Pale Pinkish Buff); flanks pinkish tan (Pale Cinnamon-Pink); iris coppery bronze (Capucine Orange). _Variation._--The few specimens from a limited geographic region preclude any analysis of geographic variation. All specimens, except the one described above, have the fifth toe webbed to the base of the disc. Many individuals have a bifid subarticular tubercle beneath the fourth finger. The shape of the posterior edge of the tongue varies from nearly straight and shallowly notched to bluntly rounded and emarginate. Two females (KU 58050-1) have more pointed snouts in dorsal profile than do males. Some specimens, such as KU 58048, are notably darker than the specimen described above; in dark specimens the dorsum is brown with dark brown markings; all fingers and the webbing on the hand are brown. The tarsi and feet are like those in the specimen described above, but the posterior surfaces of the thighs are yellowish tan heavily suffused with brown; the venter is cream color. In life KU 58048 had a brown (Verona Brown) dorsum with dark brown (Chocolate) markings. KU 58047 is slightly darker than KU 58048 and has scattered small white flecks on the dorsum. All specimens have the thin white line on the upper lip, but in some individuals it is indistinct. The grayish white line above the anus is present in all specimens. _Description of Tadpole._--The following description is based on KU 60049 from Río Hondo, 9.5 kilometers south of Pueblo Nuevo Solistahuacán, Chiapas, México (Figs. 4B and 6B). No limb buds; total length, 36.2 mm.; body length, 11.1 mm.; body length/total length, 30.6 per cent. Body moderately depressed, slightly wider than deep, ovoid in dorsal profile; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils slightly protuberant and directed anteriorly, somewhat closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Caudal fin low, acutely rounded posteriorly; depth of caudal musculature slightly more than one-half greatest depth of caudal fin; caudal musculature extending nearly to tip of tail. Mouth large; lips having deep lateral folds; two complete rows of papillae on lips; five or six rows of papillae laterally. Beaks moderately developed, bearing small peglike serrations; moderately wide lateral projections on upper beak; tooth-rows 4/6; upper rows subequal in length; fourth row interrupted medially; length of lower rows 1-4 subequal to upper rows; fifth and sixth lower rows decreasing in length; first lower row interrupted medially. Body brown above; tip of snout cream color; venter creamy white; caudal musculature creamy tan; caudal fin transparent; cream-colored crescent-shaped mark on posterior edge of body and anterior part of caudal musculature, bordered posterodorsally by dark brown blotch; four dark brown blotches on dorsum of anterior part of caudal musculature; scattered brown flecks on caudal musculature and fin; eye silvery bronze in life. _Variation._--The variation in size and proportions is given in Table 2. All specimens have 4/6 tooth-rows; in some the first lower row is interrupted medially. Specimens from Jacaltenango and two kilometers west of San Pedro Necta, Depto. Huehuetenango, Guatemala, have weakly developed sixth lower tooth-rows. The cream-colored crescent-shaped mark is distinct in all specimens; the dorsal blotches on the anterior part of the caudal musculature are narrow and do not extend far onto the sides of the tail. The blotches are most distinct in small tadpoles and sometimes indistinct in large ones. _Comparisons._--_Ptychohyla euthysanota macrotympanum_ can be distinguished from both _P. spinipollex_ and _P. leonhardschultzei_ by the absence of bold black and white marbling on the flanks, as well as by the characters given in the diagnosis; furthermore, from the former it differs in having more and smaller horny nuptial tuberosities and from the latter by having the snout, in lateral profile, rounded above instead of angulate. _Ptychohyla euthysanota macrotympanum_ differs from _P. e. euthysanota_ by normally having a paler dorsum, narrower stripe on upper lip, and no distinct lateral stripe. _Ptychohyla euthysanota macrotympanum_ occurs sympatrically with _Plectrohyla guatemalensis_ and _P. matudai matudai_. Each of the last two has a bony prepollex, rather rugose skin on the dorsum, and more squat body. Other sympatric species are _Hyla walkeri_, which has a green dorsum with brown markings and a rather pointed snout, and _Hyla sumichrasti_, a small yellow frog usually lacking vomerine teeth. _Life History._--This species breeds in clear mountain streams in mixed pine and broad-leafed forest. Males call from trees and bushes along the streams. The breeding call consists of a soft "wraack," repeated three to nine times with intervals of 2.7 to 3.4 seconds between notes. Each note has a duration of 0.60 to 0.65 second, and a rate of 92 to 100 pulses per second; the dominant frequency falls between 3000 and 3200 cycles per second (Pl. 11B). The call is indistinguishable from that of _P. e. euthysanota_. Tadpoles in various stages of development were found in the Río Hondo, Chiapas, on June 16, 1960. The smallest tadpole has a total length of 24.1 mm.; in this individual the sixth lower tooth row has barely started to develop. A metamorphosing frog taken at the same time has a snout-vent length of 19.8 mm., a short remnant of the tail, and the mouth and tongue developed, whereas another individual having a snout-vent length of 17.8 mm. and a tail 31.0 mm. in length still has larval teeth. Three completely metamorphosed juveniles collected by L. C. Stuart at Jacaltenango, Guatemala, on June 6 and 7, 1955, have snout-vent lengths of 16.0, 16.0, and 16.1 mm. _Remarks._--Tanner (1957:52) based the description of _Hyla macrotympanum_ on a single female, which, of course, lacked the characters diagnostic of _Ptychohyla_. On the basis of general external characters Tanner suggested that _Hyla macrotympanum_ was related to _H. miotympanum_, from which it differed in having a larger tympanum and a bifid subarticular tubercle beneath the fourth finger. The collection of additional females, together with males of the species, has shown that _Hyla macrotympanum_ is a _Ptychohyla_. Intergradation between _Ptychohyla euthysanota_ and _P. macrotympanum_ has not been demonstrated. Currently their ranges are separated by the dry valleys of the Río Grijalva and Río Cuilco. The similarity in structure of the adults and tadpoles and the indistinguishable breeding calls are the basis for considering the two populations subspecies. _Distribution._--This species occurs in mixed pine and broad-leafed forests at elevations of 700 to 1700 meters on the southern slopes of the Chiapan Highlands and Sierra de Cuchumatanes, in Guatemala. These forests are on the south facing slopes north of the valleys of the Río Grijalva and Río Cuilco. _Specimens examined._--MEXICO: _Chiapas_: 6 km. NE of Chiapa de Corzo, TCWC 16183; 16 km. E of Chiapa de Corzo, AMNH 62141; Linda Vista, 2 km. NW of Pueblo Nuevo Solistahuacán, KU 58049-51, 59939 (skeleton); _Río Hondo, 9.5 km. S of Pueblo Nuevo Solistahuacán_, KU 58047-8, 60046-7, 60048-9 (tadpoles); San Fernando, MZTG 15, 17; Tonina (ruins), KU 41592. GUATEMALA: _Huehuetenango_: Jacaltenango, UMMZ 123139 (tadpoles); 0.5 km. E of Jacaltenango, UMMZ 123142-3; 2 km. S of Jacaltenango, UMMZ 123141; 2 km. W of San Pedro Necta, UMMZ 123140 (tadpoles). [Illustration: PLATE 14 _Ptychohyla leonhardschultzei_ (KU 64117). × 2.] =Ptychohyla leonhardschultzei= (Ahl) _Hyla leonhard-schultzei_ Ahl, Zool. Anz., 106:185-186, fig. 1, April 15, 1934 [Holotype.--ZMB 34353 from Malinaltepec, Guerrero, México; Leonhard Schultze collector]. Smith and Taylor, Bull. U. S. Natl. Mus., 184:87, June 17, 1948. _Hyla godmani_, Ahl, Zool. Anz., 106:186, April 15, 1934. _Hyla pinorum_ Taylor, Proc. Biol. Soc. Washington, 50:46-48, pl. 2, fig. 2, April 21, 1937 [Holotype.--UIMNH 25049 from Agua del Obispo, Guerrero, México; Edward H. Taylor collector]. Smith and Taylor, Bull. U. S. Natl. Mus., 194:87, June 17, 1948. _Ptychohyla adipoventris_ Taylor, Univ. Kansas Sci. Bull., 30:41-45, May 15, 1944 [Holotype.--UIMNH 25047 from Agua del Obispo, Guerrero, México; Edward T. Taylor collector]. Smith and Taylor, Bull. U. S. Natl. Mus., 194:91, June 17, 1948. Taylor, Amer. Mus. Novitates, 1437:16, December 7, 1949. Stuart, Proc. Biol. Soc. Washington, 67:169, August 5, 1954. _Hyla milleri_ Shannon, Proc. U. S. Natl. Mus., 101:473-477, figs. 92b, 93a-c, May 17, 1951 [Holotype.--USNM 123700 from San Lucas Camotlán, Oaxaca, México; Walter S. Miller collector]. _Ptychohyla leonhard-schultzei_, Duellman, Herpetologica, 16:191-197, figs. 1-3, September 23, 1960; Univ. Kansas Publ. Mus. Nat. Hist., 13:351, April 27, 1961. _Diagnosis._--Rostral keel present; snout in lateral profile not rounded above; interorbital region much broader than eyelid; distal subarticular tubercle beneath fourth finger bifid or double; no white stripe on edge of upper lip; flanks white with black spots. _Description._--The following description is based on KU 64117 from Vista Hermosa, Oaxaca, México (Pl. 14). Adult male having a snout-vent length of 35.6 mm.; tibia length, 18.0 mm.; tibia length/snout-vent length, 50.5 per cent; foot length, 14.3 mm.; head length, 10.7 mm.; head length/snout-vent length, 30.1 per cent; head width, 10.6 mm.; head width/snout-vent length, 29.8 per cent; diameter of eye, 3.6 mm.; diameter of tympanum, 1.8 mm.; tympanum/eye, 50.0 per cent. Snout in lateral profile square, not rounded above, and in dorsal profile rounded with pointed tip resulting from vertical rostral keel; canthus pronounced; loreal region barely concave; lips thick, rounded, and barely flaring; nostrils protuberant; internarial distance, 3.2 mm.; top of head flat; interorbital distance, 3.8 mm., and approximately a fifth broader than width of eyelid, 3.2 mm. A moderately heavy dermal fold from posterior corner of eye above tympanum and curving ventrad to anterior edge of insertion of forelimb, covering upper edge of tympanum; tympanum round, its diameter equal to its distance from eye. Forearm moderately robust, having distinct dermal fold on wrist; row of small, low, rounded tubercles along ventrolateral surface of forearm; pollex only slightly enlarged, bearing triangular patch of small horn-covered spines (56 on right, 62 on left); second finger noticeably shorter than fourth; subarticular tubercles round, distal ones on third and fourth toes bifid; discs moderate in size, that of third finger slightly larger than diameter of tympanum; no web between first and second fingers; other fingers one-third webbed. Heels broadly overlap when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; a low rounded tarsal fold on distal half of tarsus; inner metatarsal tubercle elevated, flat, and elliptical; outer metatarsal tubercle at base of fourth toe, round; row of low, sometimes indistinct, tubercles from heel to base of fifth toe; subarticular tubercles round; length of digits from shortest to longest 1-2-3-5-4, third and fifth being about equal in length; third and fifth toes webbed to base of disc; fourth toe webbed to base of penultimate phalanx; discs of toes much smaller than on fingers. Anal opening near dorsal surface of thighs; short anal flap; opening bordered laterally by heavy dermal fold and ventrolaterally by large tubercles. Skin of dorsum and ventral surfaces of forelimbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands moderately developed, reaching axilla but not to groin and broadly separated midventrally. Tongue cordiform, shallowly notched behind and barely free posteriorly; vomerine teeth 4-3, situated on transverse elevations between ovoid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus. Dorsal ground-color of head, body, and limbs pale tan with large interconnected dark brown blotches on head and body and broad dark brown transverse bands on limbs; dorsal surfaces of first and second fingers and of webbing of hands pale brown; dorsal surfaces of third and fourth fingers dark brown; anterior surfaces of thighs flesh-color; posterior surfaces of thighs brown; dorsal surfaces of tarsi and feet dark brown; narrow white stripe along ventrolateral edges of forearms and tarsi; a faint creamy white stripe above anal opening; axilla white; flanks creamy white, boldly spotted with black; throat and chest white; ventral surfaces of tarsi and feet dark brown; other ventral surfaces dusty cream color; large brown spots on chin and anterior part of abdomen. In life the dorsum was reddish brown (Orange-Cinnamon) with dark brown (Chocolate) blotches; first and second fingers and webbing on hand pale reddish brown (Cinnamon); webbing on feet dark brown (Clove Brown); flanks pale creamy white (Pale Olive Buff) with dark brown (Bone Brown) spots; iris reddish bronze (Apricot Orange). _Variation._--No noticeable geographic variation is apparent in the few available specimens; variations in proportions are given in Table 1. The distal subarticular tubercle of the fourth finger is either bifid or double in all specimens; that on the third finger usually is bifid, sometimes single. The vertical rostral keel is prominent in all freshly preserved specimens; in some older specimens it is indistinct. The tongue always is notched posteriorly; in some individuals the notch is shallow; in others it is deep. Some specimens are paler and less boldly marked than the specimen described above. All specimens from Agua del Obispo and some specimens from the northern slopes of the Sierra Madre Oriental in Oaxaca have a pale tan dorsum with brown markings. In most individuals the white color in the axilla extends onto the posterior edge of the upper arm. The creamy white color of the flanks is constant and usually extends slightly dorsad in the inguinal region. The white stripe above, and sometimes continuing down beside, the anal opening varies from a thin indistinct line or row of flecks to a distinct continuous stripe. Two specimens have dark brown spots on the belly; in the others the spots are confined to the flanks and throat. _Description of tadpole._--The following description is based on KU 68556 from 7.5 kilometers south of Yetla, Oaxaca, México (Figs. 4C and 6C). No limb buds; total length, 37.3 mm.; body length, 12.2 mm.; body length/total length, 32.7 per cent; body slightly depressed, barely wider than deep, ovoid in dorsal profile; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant and directed anterolaterally, about midway between snout and eye; spiracle sinistral and posteroventrad to eye; anal tube dextral. Caudal fin low, bluntly rounded posteriorly; greatest depth of caudal musculature about one-half depth of caudal fin; musculature extends nearly to tip of tail. Mouth large; lips having deep lateral folds; two complete rows of papillae on lips; five to seven rows of papillae laterally; beaks moderately developed, bearing short peglike serrations; moderately wide lateral projections on upper beak; tooth-rows 4/6; upper rows subequal in length; fourth row interrupted medially; length of lower rows 1-4 equal to upper rows; fifth and sixth lower rows shorter; first lower row interrupted medially. Body brown above; tip of snout brown; venter creamy gray; caudal musculature creamy tan; caudal fin transparent; cream-colored crescent-shaped mark on posterior edge of body; dark brown flecks on caudal musculature and all except anterior two-thirds of ventral caudal fin; large brown square blotches on dorsum of caudal fin; eye reddish brown in life. _Variation._--The variation in size and proportions is given in Table 2. With the exception of one specimen having a short, broken, seventh tooth-row, all specimens have 4/6 tooth-rows that are like those described above. In some specimens the brown blotches on the dorsum of the caudal musculature are fused and marked with cream-colored flecks. _Comparisons._--_Ptychohyla leonhardschultzei_ differs from all other members of the _Ptychohyla euthysanota_ group in having a square snout, and further differs from _P. spinipollex_ in more numerous and smaller nuptial spines and in transverse, instead of posteromedially slanting, vomerine processes between the inner nares. _Ptychohyla leonhardschultzei_ differs from _P. euthysanota_ in having a rostral keel and in having white flanks boldly spotted with black. All small hylids that are sympatric with _Ptychohyla leonhardschultzei_ are either yellow (_Hyla dendroscarta_ and _H. melanomma_) or green (_Hyla erythromma_, which has a red eye, _Hyla hazelae_, which has a black line on the canthus, and _Ptychohyla ignicolor_, which has red flash colors on the thighs). _Life History._--This frog has been found along streams in cloud forests and in pine-oak forest. Males call from vegetation along the stream or from rocks in and at the edge of the stream. The call is a single, long, soft "wraack," repeated at intervals of anywhere from several seconds to three or four minutes. Each note has a duration of 0.62 to 0.95 of a second and a rate of 76 to 78 pulses per second; the dominant frequency falls between 2700 and 2800 cycles per second (Pl. 11C). Tadpoles were found in several streams in northern Oaxaca. A tadpole having a total length of 21.1 mm. has three upper and four lower tooth-rows well developed; the fourth upper and fifth lower rows are weakly present, and the sixth lower row has not started to develop. Two metamorphosed young have snout-vent lengths of 15.2 and 15.5 mm. _Remarks._--Four specific names have been applied to this species. Ahl (1934:185) based his description of _Hyla leonhardschultzei_ on a small, poorly preserved female. Taylor (1944:41) proposed the generic name _Ptychohyla_ for a species (named therein as _P. adipoventris_) of hylid having ventrolateral glands and horn-covered nuptial spines. Obviously, Taylor was unaware that _Hyla leonhardschultzei_ was the same species. Earlier Taylor (1937:46) described _Hyla pinorum_. The types of all of these species came from the Pacific slopes of the Sierra del Sur in Guerrero. Examination of the types and other available specimens shows that they are representatives of a single species. The type of _Hyla pinorum_ is an immature male having a snout-vent length of 26.7 mm. All of these specimens have the square snout and black and white flanks characteristic of _Ptychohyla leonhard-schultzei_. Although Shannon (1951:473) based his description of _Hyla milleri_ on a male having well-developed ventrolateral glands, he overlooked the presence of these glands in his description and discussion of relationships. The acquisition of more specimens from northern Oaxaca has shown that _Hyla milleri_ is the same as _Ptychohyla leonhardschultzei_. _Distribution._--This species is known from pine-oak forest and cloud forest on the Pacific slopes of the Sierra Madre del Sur in Guerrero and Oaxaca and from the Atlantic slopes of the Sierra Madre Oriental in northern Oaxaca. Specimens have been collected at elevations between 700 and 1650 meters. Probably the species occurs in humid forests at similar elevations around the eastern end of the Mexican Highlands in Oaxaca. _Specimens examined._--MEXICO: _Guerrero_: Agua del Obispo, CNHM 123489-90, 126651, 106300, MCZ 29639, UIMNH 25047, 25049, USNM 114551; Malinaltepec, ZMB 34351, 34353. _Oaxaca_: 2.5 km. N of La Soledad, KU 58061; San Lucas Camotlán, UIMNH 3201, USNM 123700-1; Vista Hermosa, KU 64116-7, 64119, 68560 (tadpoles), 71344, 71717-8 (tadpoles), UMMZ 119604; 5 km. S of Yetla, KU 60045 (tadpoles); _7.5 km. S of Yetla_, KU 64118, 68556-7 (tadpoles), 68559 (tadpoles), 68561 (2 young), 68630 (skeleton), UMMZ 115514-5, 118863 (tadpoles); 9 km. S of Yetla, KU 68558 (tadpoles). [Illustration: PLATE 15 _Ptychohyla spinipollex_ (KU 58054). × 2.] =Ptychohyla spinipollex= (Schmidt) _Hyla euthysanota_, Dunn and Emlen, Proc. Acad. Nat. Sci. Philadelphia, 84:25, March 22, 1932. _Hyla spinipollex_ Schmidt, Proc. Biol. Soc. Washington, 49:45-46, May 1, 1936 [Holotype.--MCZ 21300 from the mountains behind Ceiba, Depto. Atlantidad, Honduras; Raymond E. Stadelman collector]. Stuart, Misc. Publ. Mus. Zool. Univ. Michigan, 69:32-34, figs. 5-6, June 12, 1948; Contr. Lab. Vert. Biol. Univ. Michigan, 45:22, 52, 54, 57, May, 1950; Proc. Biol. Soc. Washington, 67:169, August 5, 1954. _Ptychohyla spinipollex_, Stuart, Contr. Lab. Vert. Biol. Univ. Michigan, 68:48, November, 1954. Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 13:351, April 27, 1961. _Diagnosis._--Rostral keel present; snout in lateral profile rounded above; eyelid nearly as wide as interorbital region; flanks white with brown spots; belly spotted; nuptial spines pointed and moderate in size. _Description._--The following description is based on KU 58054 from Finca Los Alpes, Depto. Alta Verapaz, Guatemala (Pl. 15). Adult male having a snout-vent length of 37.7 mm.; tibia length, 18.2 mm.; tibia length/snout-vent length, 48.2 per cent; foot length, 15.8 mm.; head length, 11.7 mm.; head length/snout-vent length, 31.0 per cent; head width, 11.7 mm.; head width/snout-vent length, 31.0 per cent; diameter of eye, 3.6 mm.; diameter of tympanum, 1.9 mm.; tympanum/eye, 52.7 per cent. Snout in lateral profile nearly square, slightly rounded above, and in dorsal profile rounded with a pointed tip resulting from vertical rostral keel; canthus pronounced; loreal region barely concave; lips thick, rounded, and barely flaring; nostrils protuberant; internarial distance, 3.0 mm.; top of head flat; interorbital distance, 3.7 mm., about equal to width of eyelid, 3.6 mm. A heavy dermal fold from posterior corner of eye above tympanum to point above insertion of forearm, covering upper edge of tympanum; tympanum round, its diameter equal to its distance from eye. Forearm moderately robust, having faint dermal fold on wrist; row of low, rounded tubercles along ventrolateral edge of forearm; pollex only slightly enlarged, bearing triangular patch of moderate-sized, pointed, horn-covered spines (38 on right, 43 on left); second finger noticeably shorter than fourth; subarticular tubercles round, distal one on fourth finger bifid; discs of fingers of moderate size, that of third finger slightly smaller than diameter of tympanum; vestigial web between first and second fingers; other fingers one-third webbed. Heels broadly overlapping when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; distinct, but low, tarsal fold extending length of tarsus; inner metatarsal tubercle elevated, flat, and elliptical; outer metatarsal tubercle small and round, near base of fourth toe; row of low indistinct tubercles from heel to base of fifth toe; subarticular tubercles round; length of toes from shortest to longest 1-2-3-5-4, the third and fifth being about equal in length; third and fifth toes webbed to base of disc; fourth toe webbed to base of penultimate phalanx; discs of toes slightly smaller than those on fingers. Anal opening near upper edge of thighs; opening bordered laterally by moderately heavy dermal folds and ventrolaterally by tubercles. Skin of dorsum and ventral surfaces of forelimbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands barely evident. Tongue ovoid, barely notched behind and slightly free posteriorly; vomerine teeth 2-3, situated on V-shaped elevations between round inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus. Dorsal ground-color of head, body, and limbs grayish tan with dark brown reticulations on head and body and dark brown transverse bars or spots on limbs; first and second fingers cream color; third and fourth fingers and webbing on hands pale grayish brown; anterior surfaces of thighs reddish tan; posterior surfaces of thighs yellowish tan; tarsi and toes pale grayish tan with brown flecks; webbing on foot pale brown; faint white stripe along ventrolateral edges of tarsi and forearms; narrow white line above and beside anal opening; no white stripe on edge of upper lip; axilla pale flesh-color; throat, chest, and ventral surfaces of limbs pale creamy gray; belly white with scattered brown flecks; flanks grayish white with dark brown flecks; ventral surfaces of tarsi dark brown; ventrolateral glands grayish tan. In life the dorsal ground-color of the head, body, fore limbs, and thighs was yellowish tan (Pinkish Buff); dorsal surfaces of shanks and tarsi pale yellowish tan (Pale Pinkish Buff); markings on head and back brown (Snuff Brown) to dark brown (Chocolate); dark bands on limbs brown (Tawny-Olive); first and second fingers creamy tan (Light Pinkish Cinnamon); posterior surfaces of thighs creamy tan (Light Pinkish Cinnamon); third and fourth fingers and webbing on hand grayish brown (Avellaneous); webbing on feet dark brown (Olive Brown); axilla pale pink (Hydrangea Pink); flanks buff (Cream-Buff) becoming yellow (Lemon Chrome) in groin; spots on flanks dark brown (Clove Brown); iris dull grayish bronze (Orange-Citrine). _Variation._--The distal subarticular tubercle beneath the fourth finger is bifid in about two-thirds of the specimens; in the rest it is round. The posterior edge of the tongue varies from being emarginate to shallowly notched. In most specimens the row of tubercles along the outer edge of the tarsus is made up of discrete tubercles, but in some individuals the tubercles form a nearly continuous dermal fold. Most specimens have the vomerine teeth situated on V-shaped elevations, but in some individuals the elevations are more nearly transversely situated between the inner nares. All 42 specimens from Finca Los Alpes, Guatemala, have dark brown spots and flecks on the venter. Some individuals have only a few flecks on the throat and a few large spots on the flanks, as does KU 64125. Other specimens, such as KU 64132, have dense spotting over the entire venter. The color of the dorsum varies from pale tan to dark brown with darker brown markings; the white line above the anus is present in all specimens, but in some it is indistinct. KU 58053 and 64127 have a dark brown dorsum with large pale tan, square blotches; in life the blotches were pale tan (Pinkish Buff); the rest of the dorsum was dark brown (Sayal Brown). KU 58052 is dark brown with many small white flecks on the dorsum; in life the dorsum was deep olive brown (Dark Olive). Aside from the differences mentioned above, all specimens from Guatemala are similar in coloration. Three specimens from Honduras (MCZ 21300 and UMMZ 113102-3) have unspotted white venters. MCZ 21300, the holotype of _P. spinipollex_, lacks a white stripe above the anal opening, whereas the stripe is indistinct in UMMZ 113102-3. _Description of tadpole._--The following description is based on KU 60053 from Fina Los Alpes, Depto. Alta Verapaz, Guatemala (Figs. 4D and 6D). No limb buds; total length, 37.2 mm.; body length, 12.2 mm.; body length/total length, 32.8 per cent. Body rounded, not depressed, as wide as deep, ovoid in dorsal profile; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant and directed anterolaterally, somewhat closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Caudal fin low, bluntly rounded posteriorly; greatest depth of caudal musculature about one-half depth of caudal fin; musculature extends nearly to tip of tail. Mouth large; lips having deep lateral folds; two complete rows of papillae on lips; six or seven rows of papillae laterally; beaks moderately developed, bearing fine blunt serrations; slender lateral projections on upper beak; tooth-rows 4/7; upper rows subequal in length; fourth row interrupted medially; lower rows 1-4 equal in length to upper rows; lower rows 5-7 decreasing in length; first lower row interrupted medially. Top of head and tip of snout brown; venter creamy gray; caudal musculature tan; caudal fin transparent; faint cream-colored, narrow, crescent-shaped mark on posterior edge of body, not bordered posteriorly by dark brown mark; brown flecks scattered on caudal musculature and caudal fin; only a few flecks on anterior half of ventral caudal fin; eye bronze-color in life. _Variation._--The variation in size and proportions as compared with tadpoles of other species is given in Table 2. Of the 57 tadpoles of this species that I have examined, 21 have only six lower tooth-rows, although in some of these specimens a faint ridge for a seventh row is present. In those specimens having seven lower rows, the seventh often is broken. There is considerable variation in coloration. None has a distinct cream-colored, crescent-shaped mark bordered posteriorly by a dark brown bar or triangle, as in the other species in the _Ptychohyla euthysanota_ group. Most specimens have a rather indistinct crescent; some have no crescent. In a few specimens there is a weakly outlined dark mark posterior to the crescent. Some specimens in a series of tadpoles from 32 kilometers north of Morazán, Baja Verapaz, Guatemala, have faint dorsal blotches on the dorsal musculature, much like those in tadpoles of _Ptychohyla leonhardschultzei_. _Comparisons._--_Ptychohyla spinipollex_ differs from all other species in the genus by having moderate-sized, instead of small, pointed nuptial spines; also it has fewer spines than the other species (see discussion of this character in Analysis of Data). The nearly equal interorbital breadth and width of the upper eyelid also is diagnostic of this species. Other hylids sympatric with _Ptychohyla spinipollex_ include three species of _Plectrohyla_, each of which has a bony prepollex, heavy body, and rugose skin on the dorsum. The only other sympatric hylid that could be confused with _Ptychohyla spinipollex_ is _Hyla bromeliacea_, which has a round snout and yellowish tan dorsum not marked with dark brown. _Life History._--At Finca Los Alpes, Guatemala, in July, 1960, and in August, 1961, calling males were found on bushes and trees along cascading mountain streams. The breeding call consists of a soft "wraack," repeated at intervals of 45 seconds to four minutes. Each note has a duration of about .46 of a second and a rate of 147 pulses per second. The dominant frequency is 4300 cycles per second (Pl. 11A). Tadpoles have been found in cascading mountain streams. Two metamorphosed young have snout-vent lengths of 15.0 and 15.5 mm. _Remarks._--There is little doubt that all of the specimens herein referred to _Ptychohyla spinipollex_ are conspecific. However, the three specimens from Honduras, including the type of _Ptychohyla spinipollex_, differ from Guatemalan specimens in lacking all dark spotting on the venter. Additional specimens from Honduras and eastern Guatemala may show that two subspecies are recognizable, in which case the nominal subspecies will be the population in Honduras. _Distribution._--This species lives in cloud forests at elevations of 800 to 1700 meters on the Atlantic side of the Guatemalan Highlands from the Sierra de Cuchumatanes in western Guatemala eastward to central Honduras. _Specimens examined._--GUATEMALA: _Alta Verapaz_: Finca Chichén, UMMZ 90876 (tadpoles); Finca Los Alpes, KU 58052-60, 59939 (skeleton), 60053 (tadpoles), 64122-41, 68562, 68563 (tadpoles), 68631-2 (skeletons), MCZ 35000-1, UMMZ 90873, 90874 (3), 90875 (tadpoles); La Primavera, UMMZ 90877 (tadpoles); Panzamalá, UMMZ 90878 (tadpoles). _Baja Verapaz_: 32 km. N of Morazán, KU 68564 (tadpoles); _Santa Elena_, UMMZ 98119, 98120 (2). _Huehuetenango_: 1 km. E of Barillas, UMMZ 123136-7 (tadpoles). _Progreso_: Finca Bucaral, UMMZ 106783 (3), 123138 (tadpoles), S-1292 (skeleton). HONDURAS: _Atlantidad_: Mountains behind Ceiba, MCZ 21300. _Morazán_: Cerro Uyuca, UMMZ 123102-3. The _Ptychohyla schmidtorum_ Group Two species in group; adults having only vestige of web between fingers and lacking tarsal fold; pollex of breeding males lacking spinous, horny, nuptial tuberosities; mouth of tadpole greatly expanded, funnel-shaped, lacking lateral folds, and having 3/3 tooth-rows; breeding call consisting of series of short notes. =Ptychohyla schmidtorum= _Diagnosis._--Diameter of tympanum more than half of diameter of eye; internarial region depressed; toes three-fourths webbed; no red flash-colors on thighs. [Illustration: PLATE 16 _Ptychohyla schmidtorum schmidtorum_ (KU 58043). × 2.] =Ptychohyla schmidtorum schmidtorum= Stuart _Ptychohyla schmidtorum_ Stuart, Proc. Biol. Soc. Washington, 67:169-172, August 5, 1954 [Holotype.--CNHM 27055 from El Porvenir (17 kilometers air-line west of San Marcos), Depto. San Marcos, Guatemala; Karl P. Schmidt collector]. Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 13:351, 355, April 27, 1961. _Diagnosis._--Vomerine teeth 5-11; dorsum dark brown; white spot below eye; eye red in life. _Description._--The following description is based on KU 58043 from Finca La Paz, Depto. San Marcos, Guatemala (Pl. 16). Adult male having snout-vent length of 31.6 mm.; tibia length, 15.0 mm.; tibia length/snout-vent length, 47.5 per cent; foot length, 12.5 mm.; head length, 10.2 mm.; head length/snout-vent length, 32.3 per cent; head width, 9.9 mm.; head width/snout-vent length, 31.3 per cent; diameter of eye, 3.4 mm.; diameter of tympanum, 1.8 mm.; tympanum/eye, 52.9 per cent. Snout in lateral profile nearly square, slightly rounded above and below, and in dorsal profile bluntly squared; canthus pronounced; loreal region concave; lips thick, rounded, and flaring; nostrils protuberant; internarial distance, 2.2 mm.; internarial region depressed; top of head flat; interorbital distance, 3.4 mm., much greater than width of eyelid, 2.5 mm. Thin dermal fold from posterior corner of eye above tympanum to insertion of forelimb, covering upper edge of tympanum; tympanum round, its diameter equal to its distance from eye. Forearm slender, lacking distinct dermal fold on wrist; row of low rounded tubercles along ventrolateral edge of forearm; pollex slightly enlarged; no nuptial spines; second and fourth fingers about equal in length; subarticular tubercles small and round, distal one beneath fourth finger bifid; discs small, that of third finger noticeably smaller than tympanum; no web between first and second fingers; vestige of web between other fingers. Heels overlap when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; no tarsal fold; inner metatarsal tubercle large, flat, and elliptical; outer metatarsal tubercle small, ovoid, slightly more distal than inner; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third and fifth toes webbed to base of discs; fourth toe webbed to base of penultimate phalanx; discs of toes smaller than on fingers. Anal opening directed posteriorly at upper edge of thighs; no anal flap; pair of large tubercles below anal opening and smaller tubercles farther below. Skin of dorsum and ventral surfaces of forelimbs and shanks smooth; that of belly and ventral surfaces of thighs granular. Ventrolateral glands well developed, reaching axilla and groin and narrowly separated on chest. Tongue ovoid, emarginate posteriorly, and only slightly free behind; vomerine teeth 3-3, situated on small triangular elevations between ovid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus. Dorsum of head, body, and limbs reddish brown with indistinct, irregular darker brown markings on body and dark brown transverse bands or spots on limbs; first and second fingers creamy white; third and fourth fingers brown; dorsal surfaces of tarsi and third, fourth, and fifth toes tan with brown spots; first and second toes and webbing on feet creamy tan; enamel-white stripe along edge of upper lip continuing over, and on posterior edge of, forearm to groin, expanded to form spot below eye; belly white, unspotted; ventrolateral glands pale brown; ventral surfaces of hind limbs and anterior and posterior surfaces of thighs cream color; enamel-white stripe on heel; creamy white stripe along ventrolateral edges of tarsi and forearms. In life dorsum reddish brown (Terra Cotta) with dark brown (Burnt Umber) markings; first and second fingers and first and second toes orange-yellow (Light Orange-Yellow); posterior surfaces of thighs pale reddish tan (Ochraceous-Salmon); webbing on feet yellowish tan (Deep Colonial Buff); belly white; iris red (Nopal Red). _Variation._--Little variation in structural characters was observed. All but five specimens have bifid subarticular tubercles beneath the fourth finger. Three specimens have cordiform tongues, and in four others the tongue is ovoid and shallowly notched behind; all other specimens have an emarginate ovoid tongue. Some individuals when active at night had a pale brown (Ochraceous-Tawny) dorsum with dull olive green (Dark Olive Buff) markings. Otherwise there was no noticeable variation in color. _Description of tadpole._--The following description is based on KU 60051 from Finca La Paz, Depto. San Marcos, Guatemala (Figs. 5A and 6E). Small hind limbs; total length, 37.9 mm.; body length, 11.6 mm.; body length/total length, 30.6 per cent. Body only slightly depressed, nearly as deep as wide, in dorsal profile ovoid, widest just posterior to eyes; in lateral profile snout rounded; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant, directed anteriorly, somewhat closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Tail long and slender; caudal fin low and rounded posteriorly; depth of caudal musculature one-half greatest depth of caudal fin; musculature not extending to tip of tail. Mouth large; thin fleshy lips greatly expanded and forming large funnel-shaped disc; width of mouth two-thirds greatest width of body; outer edge of lips having one row of small papillae; inner surfaces of mouth smooth; scattered large papillae forming one nearly complete row around teeth; other large papillae laterally; beaks moderately developed, bearing long, pointed denticulations; no lateral projections on upper beak; tooth-rows 3/3, all short; second and third upper rows subequal in length; first upper row shorter; first and third upper rows interrupted medially; first lower row interrupted medially, equal in length to second and third upper rows; second lower row slightly shorter; third lower row shortest. Body mottled brown and creamy gray above and below; mouth colored like body; caudal musculature creamy tan; caudal fin transparent; dark brown streak mid-laterally on anterior third of caudal musculature; rest of tail and all of caudal fin heavily flecked with brown; eye red in life. _Variation._--The third upper tooth-row is interrupted in all specimens; in some individuals the first upper and first lower rows are complete. The variation in size and proportions is given in Table 2. The dark brown lateral streak on the anterior part of the caudal musculature is distinct on most specimens; the only other variation in coloration is in the amount of brown flecking on the caudal musculature and fin. _Comparisons._--_Ptychohyla schmidtorum schmidtorum_ differs from _P. schmidtorum chamulae_ as stated in the diagnosis and in having pale creamy tan, as opposed to dark brown, webbing on the feet; and from _P. ignicolor_ in having a depressed, as opposed to a flat, internarial region. Tadpoles of _P. s. schmidtorum_ have a mottled appearance, as opposed to the more uniform brown color of _P. s. chamulae_. _Ptychohyla schmidtorum schmidtorum_ and several species of _Plectrohyla_ are sympatric. All species of the latter genus have a bony prepollex, rugose skin on the dorsum, and heavy body; also sympatric is _Ptychohyla e. euthysanota_, which has a tarsal fold and in breeding males spinous nuptial tuberosities. _Life History._--This species breeds in clear mountain streams where males call from vegetation along the stream. The call consists of series of short notes, three to nine notes per series, sounding like "raa-raa-raa." The duration of each note is approximately .065 of a second, and has a rate of 96 to 119 pulses per second; the dominant frequency is about 3400 cycles per second. The call is almost indistinguishable from that of _Ptychohyla schmidtorum chamulae_. Tadpoles and metamorphosing young were found at Finca La Paz, Guatemala, in late July, 1960. Two young lacking tails but not having completely developed mouths have snout-vent lengths of 14.2 and 14.6 mm. L. C. Stuart collected four metamorphosing young at Finca La Paz on May 6, 1949. By May 10 the frogs were completely metamorphosed, at which time they had snout-vent lengths of 15.5 to 17.0 (average 16.1) mm. _Remarks._--There is no doubt that this frog is most closely related to _Ptychohyla schmidtorum chamulae_, even though the ranges of the two subspecies are separated by the interior depression of Chiapas. Since at least at Finca La Paz, Guatemala, _P. s. schmidtorum_ occurs with _P. e. euthysanota_, it is surprising that the former species has not been found at more localities along the Pacific slopes on northern Central America. At Finca La Paz in July, 1960, _P. s. schmidtorum_ was more abundant than _P. e. euthysanota_. _Distribution._--This species is known only from a limited area at elevations between 1300 and 2200 meters on the Pacific slopes of the Sierra Madre in extreme eastern Chiapas and western Guatemala. _Specimens examined._--MEXICO: _Chiapas_: Finca Irlandia, UMMZ 105429-30. GUATEMALA: _San Marcos_: El Porvenir, CNHM 20755, 20761, 69904, UMMZ 80918; Finca La Paz, 2 km. W of La Reforma, KU 58016-44, 59940-2 (skeletons), 60050 (3 young), 60051 (tadpoles), 60052 (4 young), MCZ 34998-9, UMMZ 123144-7 (tadpoles). [Illustration: PLATE 17 _Ptychohyla schmidtorum chamulae_ (KU 58069). × 2.] =Ptychohyla schmidtorum chamulae= Duellman _Ptychohyla chamulae_ Duellman, Univ. Kansas Publ. Mus. Nat. Hist., 13: 354-357, pl. 25, fig. 2, April 27, 1961 [Holotype.--KU 58063 from 6.2 kilometers south of Rayón Mescalapa, Chiapas, México; William E. Duellman collector]. _Diagnosis._--Vomerine teeth 4-6; dorsum bright green; white lateral stripe; eye reddish bronze in life. _Description._--The following description is based on KU 58069 from 6.2 kilometers south of Rayón Mescalapa, Chiapas, México (Pl. 17). Adult male having a snout-vent length of 27.6 mm.; tibia length, 13.0 mm.; tibia length/snout-vent length, 47.1 per cent; foot length, 10.8 mm.; head length, 9.6 mm.; head length/snout-vent length, 34.7 per cent; head width, 9.2 mm.; head width/snout-vent length, 33.1 per cent; diameter of eye, 3.0 mm.; diameter of tympanum, 1.6 mm.; tympanum/eye, 53.3 per cent. Snout in lateral profile nearly square, slightly rounded above and below, and in dorsal profile blunt, almost square; canthus pronounced; loreal region concave; lips thick, rounded and flaring; nostrils protuberant; internarial distance, 2.5 mm.; internarial region slightly depressed; top of head flat; interorbital distance, 3.3 mm., much greater than width of eyelid, 2.5 mm. Thin dermal fold, from posterior corner of eye above tympanum to insertion of fore limb, covering upper edge of tympanum; tympanum nearly round, its diameter equal to its distance from eye. Forearm slender, lacking distinct fold on wrist; row of low, rounded tubercles on ventrolateral surface of forearm; pollex slightly enlarged, without nuptial spines; second and fourth fingers equal in length; subarticular tubercles round, that under fourth finger bifid; discs small, that of third finger noticeably smaller than tympanum; no web between first and second fingers; vestige of web between other fingers. Heels overlapping when hind limbs adpressed; tibiotarsal articulation reaches to middle of eye; no tarsal fold; inner metatarsal tubercle large, flat, and elliptical; outer metatarsal tubercle small, elliptical, slightly more distal than inner; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third and fifth toes webbed to base of disc; fourth toe webbed to base of penultimate phalanx; discs smaller on toes than on fingers. Anal opening directed posteriorly at upper edge of thighs; no anal flap; pair of large tubercles below anal opening. Skin of dorsum and of ventral surfaces of forelimbs and shanks smooth; that of throat, belly, and ventral surfaces of thighs granular. Ventrolateral glands well developed, not reaching axilla or groin and broadly separated midventrally. Tongue cordiform, shallowly notched behind and only slightly free posteriorly; vomerine teeth 2-3, situated on small triangular elevations between ovoid inner nares; openings to vocal sac large, one situated along inner posterior edge of each mandibular ramus. Dorsum of head, body and limbs reddish brown with dark purplish brown markings on back and shanks; first finger creamy tan; other fingers pale brown; dorsal surfaces of tarsi, third, fourth, and fifth toes dull tan with brown spots; first and second toes creamy tan; webbing on feet brown; anterior and posterior surfaces of thighs tan; faint creamy white stripe along ventrolateral edges of tarsi and forearms; enamel-white stripe on heel; axilla and groin gray; enamel-white stripe on edge of upper lip, continuing onto proximal upper surfaces of forelimb and on flanks to groin, widened under eye to form large spot, and bordered below on flanks by dark brown stripe; white stripe above and white spots below anal opening; throat and chest white; belly and ventral surfaces of limbs cream color; brown dash on either side of chin and brown spot on throat near angle of jaws; few brown flecks on belly; ventrolateral glands orange-tan; ventral surfaces of tarsi and feet brown. In life, dorsal surfaces of head, body, and limbs bright green (Shamrock Green); first and second fingers pale orange (Apricot Yellow); stripe on upper lip and spot below eye enamel-white; stripe on flanks silvery white, bordered below by brown (Saccardo's Umber) brown; anterior and posterior surfaces of thighs yellowish brown (Old Gold); webbing of feet dull brown (Brownish Olive); belly deep yellow (Amber Yellow); iris reddish bronze (English Red). _Variation._--Tubercles beneath the fourth fingers are bifid in 20 specimens and rounded in all others. The tongue is emarginate in 12 specimens and cordiform in all others. In most specimens the white stripe on the upper lip continues onto the flanks and to the groin; in five specimens the stripe terminates above the forearm, and in three it terminates at mid-flank. The lateral stripe is absent in two specimens. All specimens were uniform green above when found at night; later some changed to pale green (Light Oriental Green) on the dorsum with irregular yellowish tan (Naples Yellow) blotches. Most males have brown flecks on the throat and ventrolateral gland, but some specimens are immaculate below, and one has dark brown mottling on the throat. Several males have a round, orange-tan glandular area on the chin, as does _P. ignicolor_. _Description of tadpole._--The following description is based on KU 58199 from 6.2 kilometers south of Rayón Mescalapa, Chiapas, México (Figs. 5B and 6F). Hind limbs small; total length, 39.0 mm.; body length, 10.5 mm.; body length/total length, 26.9 per cent. Body barely depressed, only slightly wider than deep, widest just posterior to eyes; in dorsal profile ovoid; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant, directed anterodorsally, slightly closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Tail long and slender; caudal fin low, rounded posteriorly; depth of caudal musculature one-half greatest depth of caudal fin; musculature not extending to tip of tail. Mouth large; thin fleshy lips greatly expanded and forming funnel-shaped disc; outer edge of lips having one row of small papillae; inner surfaces of mouth smooth; scattered large papillae forming nearly one complete row around teeth; other papillae laterally; beaks moderately developed, bearing long, pointed denticulations; no lateral projections on upper beak; tooth-rows 3/3, all short; second and third upper rows subequal in length; first upper row shorter; first and third upper rows interrupted medially; first lower row interrupted medially, equal in length to second and third upper rows; second lower row slightly shorter; third lower row shortest. Body dark brown above and dark gray below; fleshy part of mouth creamy gray mottled with dark brown; caudal musculature pale tan with heavy suffusion of brown flecks; caudal fin transparent with brown spots; dark brown streak mid-laterally on anterior one-fifth of caudal musculature, bordered below by cream-colored spot; eye brown in life. _Variation._--The third upper tooth-row is interrupted in all specimens, but in some individuals the first upper row and first lower row are complete. The only noted variation in color is the intensity of brown pigmentation on the caudal musculature, which in most specimens is sufficiently dense to make the tail look brown. In some specimens the mid-lateral streak is indistinct, and the pale spot below the streak is absent. _Comparisons._--Aside from the characters listed in the diagnosis, _Ptychohyla schmidtorum chamulae_ differs from _P. schmidtorum schmidtorum_ by having dark brown webbing on the feet, instead of pale creamy tan webbing, and in having in life a yellow venter, instead of a white venter. _Ptychohyla ignicolor_ also is green in life, but has red flash-colors on the thighs, red webbing on the feet, and lacks the white lateral stripe diagnostic of _P. schmidtorum chamulae_. _Plectrohyla matudai matudai_ and _P. guatemalensis_ are sympatric with _Ptychohyla schmidtorum chamulae_. Each of the first two has a bony prepollex, rugose skin on the dorsum, and heavy body. Also living with _Ptychohyla chamulae_ are _Hyla chaneque_, a large species having a tuberculate dorsum and webbed fingers, and _Hyla bivocata_, a small yellow species having a broad, flat head, small indistinct tympanum, and an axillary membrane. _Life History._--Calling males were found on leaves of herbs and bushes by cascading streams in cloud forest. The call consists of series of short notes, three to nine notes per series, sounding like "raa-raa-raa." The duration of each note is .054 to .070 of a second, and has a rate of 96 to 110 pulses per second. The dominant frequency falls between 3350 and 3450 cycles per second (Pl. 11D). The call is almost indistinguishable from that of _Ptychohyla schmidtorum schmidtorum_. Tadpoles were found in the cascading streams; the smallest tadpole has a total length of 17.2 mm. and has only 3/2 tooth-rows. At a stream 6.2 kilometers south of Rayón Mescalapa, Chiapas, metamorphosing young were found on June 16 and August 5, 1960. Each of two completely metamorphosed young has a snout-vent length of 15.7 mm. Another having a snout-vent length of 16.2 mm. has a tail stub 2 mm. long and a completely metamorphosed mouth. Two others have snout-vent lengths of 13.6 and 14.1 mm. and tail lengths of 11.5 and 8.1 mm. respectively; in these the mouth parts are incompletely metamorphosed. _Remarks._--Duellman (1961:354) described _Ptychohyla chamulae_ and stated that it probably was most closely related to _P. schmidtorum_. Further study has revealed additional resemblance in morphological and behavioral details. It is concluded that the two populations are more realistically treated as subspecies than as species. The geographic ranges, as now known, are disjunct. _Ptychohyla schmidtorum chamulae_ inhabits cloud forest on the Atlantic slopes of the Chiapan Highlands, whereas _P. s. schmidtorum_ lives in cloud forest on the Pacific slopes of the Sierra Madre in Chiapas and Guatemala. Between their known geographic ranges are the pine clad Sierra Madre and Chiapan Highlands, and intervening sub-humid Grijalva Valley. _Distribution._--This species is known only from elevations between 1500 and 1700 meters on the Atlantic slopes of the Chiapan Highlands; it is to be expected in cloud forests on the northern slopes of the Sierra de Cuchumatanes in Guatemala. _Specimens examined._--MEXICO: _Chiapas: 15 km. N of Pueblo Nuevo Solistahuacán_, UMMZ 123325 (4); _16.5 km. N of Pueblo Nuevo Solistahuacán_, UMMZ 123322 (10); _18 km. N of Pueblo Nuevo Solistahuacán_, UMMZ 121395-9, 123324 (8), 123326 (5); _18.6 km. N of Pueblo Nuevo Solistahuacán_, UMMZ 123323 (4); _5.6 km. S of Rayón Mescalapa_, KU 58062, 58200 (tadpoles); _6.2 km. S of Rayón Mescalapa_, KU 58063-74, 58199 (tadpole), 58234-8, 59936 (skeleton). [Illustration: PLATE 18 _Ptychohyla ignicolor_ (UMMZ 119603). × 2.] =Ptychohyla ignicolor= Duellman _Ptychohyla ignicolor_ Duellman, Uni. Kansas Publ. Mus. Nat. Hist., 13:352-353, pl. 25, fig. 1, April 27, 1961 [Holotype.--UMMZ 119603 from 6 kilometers south of Vista Hermosa, Oaxaca, México; Thomas E. Moore collector]. _Diagnosis._--Diameter of tympanum less than one-half diameter of eye; internarial region flat; 3-7 vomerine teeth; toes one-half webbed; no white spot below eye; no lateral white stripe; in life dorsum green; groin and thighs having bright red flash-colors. _Description._--The following description is based on UMMZ 119603 from 6 kilometers south of Vista Hermosa, Oaxaca, México (Pl. 18). Adult male having a snout-vent length of 30.0 mm.; tibia length, 14.6 mm.; tibia length/snout-vent length, 48.7 per cent; foot length, 12.3 mm.; head length, 9.2 mm.; head length/snout-vent length, 30.7 per cent; head width, 9.3 mm.; head width/snout-vent length, 31.0 per cent; diameter of eye, 3.2 mm.; diameter of tympanum, 1.3 mm.; tympanum/eye, 40.6 per cent. Snout in lateral profile square, and in dorsal profile rounded; canthus pronounced; loreal region slightly concave; lips moderately flaring; top of head flat; nostrils protuberant; internarial distance, 2.8 mm.; internarial region flat; interorbital distance, 3.3 mm., much broader than width of eyelid, 2.8 mm. A heavy dermal fold from posterior corner of eye above tympanum to insertion of forelimb, covering upper edge of tympanum; tympanum elliptical, its greatest diameter equal to its distance from eye. Forearm moderately robust having distinct dermal fold on wrist; pollex moderately enlarged without nuptial spines; second and fourth fingers equal in length; subarticular tubercles round, none is bifid; discs on fingers moderate in size, that on third finger slightly larger than tympanum; no web between first and second fingers; vestige of web between other fingers. Heels overlap when hind limbs adpressed; tibiotarsal articulation extends to anterior corner of eye; no tarsal fold; inner metatarsal tubercle large, flat, and elliptical; outer metatarsal tubercle near inner one and triangular in shape; subarticular tubercles round; length of digits from shortest to longest 1-2-5-3-4; third toe webbed to proximal end of penultimate phalanx; fourth toe webbed to distal part of antepenultimate phalanx; fifth toe webbed to middle of penultimate phalanx; discs on toes smaller than on fingers. Anal opening directed posteriorly at upper edge of thighs; no anal flap; pair of large tubercles below anal opening; small tubercles ventral and lateral to these. Skin of dorsum and ventral surfaces of limbs smooth; that of throat and belly granular. Ventrolateral glands noticeably thickened, extending from axilla nearly to groin and only narrowly separated midventrally on chest; skin of anterior part of chin thickened and glandular. Tongue cordiform, shallowly notched behind and only slightly free posteriorly; vomerine teeth 0-3, situated on rounded elevations between somewhat larger, round inner nares; openings to vocal sac large, one situated along posterior margin of each mandibular ramus. Dorsal ground-color of head, body, and limbs dull brown with dark brown reticulations on head and body and dark brown transverse bands or spots on limbs; first and second fingers cream color; third and fourth fingers dull tan; anterior surfaces of thighs pale brown; posterior surfaces of thighs cream color with heavy suffusion of brown; dorsal surfaces of tarsi and third, fourth, and fifth toes dull brown with dark brown spots; first and second toes creamy white; webbing on foot brown; axilla and groin cream color; flanks brown; no white stripes on edge of upper lip or on flank; faint, barely discernible tan streak above anal opening; faint creamy tan line on ventrolateral edges of tarsi; throat, belly, ventral surfaces of limbs, inner edges of tarsi, and first toes cream color; outer ventral surfaces of tarsi and other toes brown; chest and throat spotted with brown; ventrolateral and chin glands orange-brown. In life the dorsum was uniform green (Cosse Green) becoming paler green (Bright Green-Yellow) on flanks, later changing to paler green (Javel Green) on dorsum with irregular darker green (Lettuce Green) markings and greenish yellow (Green-Yellow) on flanks; anterior and posterior surfaces of thighs, ventral surfaces of shanks, anterior surfaces of tarsi, and upper proximal surfaces of first, second, and third toes red (Coral Red); venter pale creamy yellow (Sulfur Yellow); iris pale golden color (Aniline Yellow). _Variation._--Of 13 specimens, six have a cordiform tongue; the others have an emarginate tongue. Five specimens have round subarticular tubercles beneath the fourth fingers; six specimens have a bifid tubercle on one hand, and two specimens have bifid tubercles on both hands. A round gland is present on the chin of all specimens; in some the gland is barely visible, but in others it is large and distinct. In two specimens the ventrolateral glands are weakly developed; in the others the glands are well developed and orange-tan. The white anal stripe varies from a thin line to a series of white flecks. Dark brown or black flecks are present on the throat, chest, and flanks of all specimens. In some the flecks are small and widely scattered; in others the flecks are larger and more numerous. All specimens were pale green above when calling at night; later they changed to dull green with darker green reticulations. The flash-colors on the thighs and in the groin vary from red to orange-red or brownish red. _Description of tadpole._--The following description is based on KU 71716 from Vista Hermosa, Oaxaca, México (Figs. 5C and 6G). Hind limbs small; total length, 39.6 mm.; body length, 11.8 mm.; body length/total length, 29.8 per cent. Body moderately depressed, only slightly wider than deep, in dorsal profile ovoid, widest just posterior to eyes; in lateral profile snout rounded; mouth directed ventrally; eyes small, directed dorsolaterally; nostrils barely protuberant, directed anteriorly, somewhat closer to eye than snout; spiracle sinistral and posteroventrad to eye; anal tube dextral. Tail long and slender; caudal fin low and rounded posteriorly; depth of caudal musculature about one-half greatest depth of caudal fin; musculature not extending to tip of tail. Mouth large; thin fleshy lips greatly expanded and forming large funnel-shaped disc; width of mouth about two-thirds greatest width of body; outer edge of lips having one row of small papillae; inner surface of mouth smooth; scattered large papillae forming one nearly complete row around teeth; other papillae laterally; one large papilla just above each end of first lower tooth-row; beaks moderately developed bearing long, pointed denticulations; no lateral projections on upper beak; tooth-rows 3/3, all short; second and third upper rows subequal in length; first upper row shorter; first lower row equal in length to second and third upper rows; second lower row slightly shorter; third lower row shortest. Body creamy gray with dark brown flecks above and below; mouth colored like body; caudal musculature creamy tan; caudal fin transparent; dark brown streak on anterior third of caudal musculature; rest of tail and all of caudal fin, except anterior two-thirds of ventral fin, heavily flecked with brown; iris silvery bronze color in life. _Variation._--The only other known tadpole, which was collected with the individual described above, differs in having only two upper tooth-rows. The first upper tooth-row seems not to have developed. _Comparisons._--From _P. schmidtorum chamulae_ and _P. s. schmidtorum_, _P. ignicolor_ differs as follows: Tympanum smaller; snout more nearly square; less webbing on toes; internarial region flat instead of depressed; white lateral stripes lacking. _Ptychohyla ignicolor_ and several small and moderate sized hylids are sympatric. From _P. ignicolor_ these hylids can be distinguished as follows: _Hyla dendroscarta_ has a round snout and yellow dorsum; _Hyla erythromma_ has a round snout, green dorsum, white flanks, and a red eye; _Hyla hazelae_ has a tarsal fold, green dorsum, and a black line on the canthus; and _Ptychohyla leonhardschultzei_ has a tarsal fold, brown dorsum, black and white flanks, and horny nuptial spines in breeding males. _Life History._--At Vista Hermosa, Oaxaca, males were calling on vegetation above small streams on March 30, 1959, and on June 28, 1962; males were found on vegetation overhanging a stream 6 kilometers south of Vista Hermosa on June 27 and July 3, 1962. The call consists of a series of short notes, three to thirteen notes per series, sounding like "raa-raa-raa." The duration of each note is about .08 of a second and has a rate of 123 to 129 pulses per second. The dominant frequency of notes in short series is about 2100 cycles per second, whereas the dominant frequency of notes in long series is about 3150 cycles per second (Pl. 11E). On June 28, 1962, two tadpoles of this species were found in a quiet pool in a spring-fed rivulet at Vista Hermosa, Oaxaca. Females are unknown. _Remarks._--The absence of a tarsal fold and of nuptial spines in breeding males, the nature of the breeding call, and the form of tadpole are characters that place _Ptychohyla ignicolor_ in the _P. schmidtorum_-group. _Distribution._--This species is known from only two localities at elevations of 1500 and 1850 meters in the cloud forest on the northern (Atlantic) slopes of the Sierra Madre Oriental in northern Oaxaca. _Specimens examined._--MEXICO: _Oaxaca: Vista Hermosa_, KU 71334, 71716 (tadpoles), UMMZ 119602; 6 km. S of Vista Hermosa, KU 71335-42, 71343 (skeleton), UMMZ 119603, 123327 (2). DISTRIBUTION AND ECOLOGY Geographic Distribution of the Species The distribution of species of _Ptychohyla_ reflects the distribution of cloud forest in southern México and northern Central America. The frogs are restricted to mountainous areas, usually at elevations higher than 1000 meters above sea level. _Ptychohyla_ does not range to great heights in the mountains, where west of the Isthmus of Tehuantepec the mountain streams are inhabited by frogs of the _Hyla bistincta_ group, and in Chiapas and Guatemala by species of _Plectrohyla_. Frogs of the _Ptychohyla euthysanota_ group have a greater combined geographic range than the species comprising the _Ptychohyla schmidtorum_ group (Fig. 7). No two species in the same group are sympatric, but members of different groups are sympatric in at least parts of their ranges. Apparently _P. leonhardschultzei_ ranges around the southern edge of the Mexican Highlands, where the species occurs on both Atlantic and Pacific slopes; as can be seen from the distribution map, there are many gaps in the known range of this species. The range of _P. euthysanota euthysanota_ is along the Pacific slopes of the Sierra Madre in Chiapas, Guatemala, and El Salvador, whereas that of _P. euthysanota macrotympanum_ is along the southern interior slopes of the Central Highlands of Chiapas and the Sierra de Cuchumatanes in Guatemala. _Ptychohyla spinipollex_ occurs on the wet Atlantic slopes of the Guatemalan and Honduranean Highlands; the range of the species in Honduras is poorly known. [Illustration: FIG. 7. Map showing locality records for the species and subspecies of _Ptychohyla_.] The frogs of the _Ptychohyla schmidtorum_ group have more restricted geographic ranges than members of the former group. _Ptychohyla schmidtorum schmidtorum_ occurs on the Pacific slopes of the Sierra Madre in Chiapas and Guatemala, where it occurs with _P. euthysanota euthysanota_; _P. schmidtorum chamulae_ is known from only two localities on the Atlantic slopes of the Central Highlands of Chiapas, where it occurs close to, but as now known not with, _P. euthysanota macrotympanum_. On the Atlantic slopes of the Sierra Madre Oriental in northern Oaxaca _P. ignicolor_ occurs with _P. leonhardschultzei_. In the Sierra de los Tuxtlas in southern Veracruz and in the cloud forests along the eastern slopes of the Sierra Madre Oriental northward to Nuevo León, _Hyla miotympanum_ seems to be the ecological replacement of _Ptychohyla_. On the Pacific slopes north of Guerrero, México, humid forests in which there are cascading mountain streams are absent; consequently, no _Ptychohyla_ are known from that region. In the mountains of El Salvador _Ptychohyla euthysanota euthysanota_ occurs sympatrically with another small stream-breeding hylid, _Hyla salvadorensis_. To the south of Honduras the highlands diminish into the lowlands of Nicaragua, where habitat suitable for _Ptychohyla_ apparently does not exist. In the mountains of Costa Rica and Panamá, the habitats occupied by _Ptychohyla_ in northern Central America are filled by a variety of stream-breeding _Hyla_, such as _Hyla legleri_, _H. rivularis_, _H. rufioculis_, _H. alleei_, and _H. uranochroa_. Although members of the genus _Ptychohyla_ occur in the southern part of the Mexican Highlands to the west of the Isthmus of Tehuantepec, the greater distribution and differentiation in the genus is in the Chiapan-Guatemalan Highlands. In this respect _Ptychohyla_ is a counterpart of _Plectrohyla_. Habitat Preference Frogs of the genus _Ptychohyla_ are ecologically associated with mountain streams at elevations between 650 and 2200 meters; in the geographic region where these frogs occur the vegetation between those elevations consists of cloud forest or pine-oak forest. In some places the frogs have been found in a mixture of oak and semi-deciduous scrub forest. At Vista Hermosa, Oaxaca, _P. leonhardschultzei_ and _P. ignicolor_ were found in cloud forest, whereas at Agua del Obispo, Guerrero, the former species was found in pine-oak forest. _Ptychohyla schmidtorum_ is known only from cloud forest; _P. euthysanota euthysanota_ and _P. spinipollex_ generally are found in cloud forest, but in some places they live in pine-oak forest. _Ptychohyla euthysanota macrotympanum_ has been found in pine-oak forest and in a mixture of oak and semi-deciduous scrub forest. With the possible exception of the members of the _Ptychohyla schmidtorum_ group, which has been found only in cloud forest, it seems as though the type of vegetation is not the controlling factor in the ecological distribution of these frogs. _Ptychohyla_ has been found only where there are clear, cascading streams overhung by vegetation, on which adults and young perch at night, or even by day. The presence of these streams, in which the tadpoles live, seems to be an important factor in the distribution of _Ptychohyla_. As has been shown previously, the tadpoles of _Ptychohyla_ are adapted for existence in torrential streams, where the water is cool, and the amount of oxygen is high. Clearly these tadpoles are unsuited for life in ponds or sluggish streams in the lowlands, where the temperature of the water is high, a layer of silt on the bottom is deep, and the amount of oxygen is low. The tadpoles cling to rocks on the bottom of the streams; there they move slowly across the rocks, apparently feeding on the thin covering of algae. Tadpoles were not observed on rocks having a thick covering of algae or moss. The tadpoles were observed to swim against the current in torrential streams, in which no fishes were found. Therefore, it seems as though the presence of the stream-habitat for the tadpoles is a significant factor in the ecological distribution of the species of _Ptychohyla_. Interspecific Competition At localities where two species of _Ptychohyla_ occur sympatrically (_P. ignicolor_ and _P. leonhardschultzei_ at Vista Hermosa, Oaxaca, and _P. euthysanota euthysanota_ and _P. schmidtorum schmidtorum_ at Finca La Paz, Depto. San Marcos, Guatemala) effort was made to determine what, if any, ecological interspecific relationships existed. Although adults of the sympatric species were found on adjacent leaves or branches of bushes overhanging the streams at both localities, segregation at the time of breeding seems to be maintained by the notably different breeding calls in sympatric species (see discussion of breeding calls). Thus, as has been shown by Blair (1956), Fouquette (1960), and others working on a variety of pond-breeding frogs and toads, the breeding call in _Ptychohyla_ acts as an important reproductive isolating mechanism. At no locality were _Ptychohyla_ and associated species of hylids found so abundantly as were species of pond-breeding hylids in the lowlands. Apparently reproductive activity is not concentrated in a short breeding season, and it is highly doubtful if the populations of these frogs are as large as those of the lowland pond-breeders. The continual humid conditions and abundance of insect food throughout the year in the cloud forest are perhaps indicative of little interspecific competition among adults of _Ptychohyla_ and other sympatric hylids. At Finca La Paz, Guatemala, tadpoles of two species of _Ptychohyla_ were ecologically segregated. The tadpoles of _P. euthysanota euthysanota_ were found in riffles in the streams, whereas those of _P. schmidtorum schmidtorum_ were found in slower water, chiefly in small pools in the streams. At Vista Hermosa, Oaxaca, tadpoles of _P. leonhardschultzei_ were found in riffles, and tadpoles of the sympatric _P. ignicolor_ were found in a small pool in a stream. Similar ecological relationships were observed for several species of Costa Rican hylids. Throughout the range of _Ptychohyla_ east of the Isthmus of Tehuantepec, members of the genus occur with species of _Plectrohyla_, all of which are larger than _Ptychohyla_, and all of which have tadpoles that live in torrential streams. Tadpoles of _Ptychohyla spinipollex_ have been found in streams inhabited by the tadpoles of _Plectrohyla guatemalensis_ and _P. quecchi_; tadpoles of _Ptychohyla euthysanota euthysanota_ and _P. schmidtorum schmidtorum_ were found in streams inhabited by tadpoles of _Plectrohyla guatemalensis_, _P. matudai_, and _P. sagorum_. In some streams great numbers of tadpoles occur. The habitat is rather restricted, and the food supply is limited. Consequently, interspecific competition among the various species of hylids whose tadpoles live in the torrential streams probably is highest during the larval stage. Unfortunately, this aspect of salientian population ecology has received no intensive study. Reproduction and Development Since the cloud forests inhabited by _Ptychohyla_ are daily bathed in clouds and have a fairly evenly distributed rainfall throughout the year, the frogs living in these forests are active throughout the year. At least some of the species evidently have a long breeding season, for I found calling males of _P. leonhardschultzei_ in February, March, and August, and found tadpoles in February, March, June, and August. Tadpoles of the various species have been obtained throughout much of the year, as follows: _P. euthysanota euthysanota_, February, March, May, and July; _P. euthysanota macrotympanum_, March, June, and August; _P. spinipollex_, February, March, April, June, July, and August; _P. schmidtorum schmidtorum_, March, May, June, July, and August; _P. schmidtorum chamulae_, June and August; _P. ignicolor_, June. I suspect that this temporal distribution more accurately reflects the seasonal activities of collectors than of the frogs. Calling frogs usually are on vegetation adjacent to or overhanging streams; some calling males of _P. spinipollex_ were on rocks in or by streams. Clasping pairs of _P. euthysanota_ and _P. schmidtorum_ were observed on vegetation by streams. Despite intensive search, no eggs were found. It is doubtful if _Ptychohyla_ deposit eggs on vegetation overhanging streams, as do centrolenids and _Phyllomedusa_, for egg-clutches of these frogs are easily found. Possibly the eggs are laid separately on vegetation above the stream, in which case they could be overlooked easily. In streams where _Ptychohyla_ and other hylid tadpoles occur, empty egg capsules have been found on the lee sides of rocks, but there is no way to determine which species laid the eggs. Numbers of eggs were counted in gravid females; the largest eggs have diameters ranging from 2.5 to 3.0 mm. The smaller species, comprising the _Ptychohyla schmidtorum_ group, have fewer eggs than do the larger species. Numbers of eggs found in females of the various species are: _P. euthysanota euthysanota_, 108; _P. euthysanota macrotympanum_, 136, 160; _P. leonhardschultzei_, 141; _P. spinipollex_, 119, 134, 143; _P. schmidtorum schmidtorum_, 59, 61, 90; _P. schmidtorum chamulae_, 60, 71, 89. Duration of the larval stage is unknown. Metamorphosing young have been found from May through August. From two to six completely metamorphosed young are available for each of the species, except for _P. ignicolor_ of which none is available. The smallest young frog is a _P. euthysanota_ having a snout-vent length of 14.2 mm.; the largest young frog is a _P. schmidtorum schmidtorum_ having a snout-vent length of 17.0 mm. PHYLOGENY OF PTYCHOHYLA The preceding data on morphology, life histories, and behavior form the basis for the following interpretation of the phylogeny of _Ptychohyla_. Additional data are needed to support some of the ideas discussed below; many of the data that are available for _Ptychohyla_ are lacking for other, possibly related, hylids. The family Hylidae is composed of several hundred species, and most of the species are poorly known. Consequently, any attempt to place _Ptychohyla_ in the over-all scheme of hylid phylogeny would be premature at this time. But, as between the five species of two species-groups here recognized as constituting the genus _Ptychohyla_, some estimate of relationships can be made. First, it is necessary to determine the validity of the genus itself. Ptychohyla as a Natural Assemblage As stated in the diagnosis of the genus, the only character that sets this group of species apart from other hylids is the presence of ventrolateral glands in the breeding males. To many systematists the thought of being able to identify to genus only breeding males is sufficiently disturbing to cause them to view with disfavor the recognition of the genus. Nonetheless, the question is raised: Do the five species herein placed in the genus _Ptychohyla_ constitute a natural assemblage? If the genus is considered to be more than a category of convenience, that is to say, a group of related species having a common origin, the primary problem is to determine whether or not the five species form a phylogenetic unit. The species of _Ptychohyla_ are divided into two groups on the basis of external morphology, breeding calls, and tadpoles. The _Ptychohyla euthysanota_ group seems to be a natural group composed of three species, all of which are more closely related to one another than to any other hylid. Likewise, the species comprising the _Ptychohyla schmidtorum_ group seem to represent a natural unit. If the presence of ventrolateral glands in breeding males is ignored, a student of salientian systematics might derive the _Ptychohyla euthysanota_ group from a hylid stock containing _Hyla miotympanum_ and _Hyla mixomaculata_. Likewise, _Ptychohyla schmidtorum_ could be placed with _Hyla uranochroa_ and related species in Costa Rica. Nonetheless, the fact remains that all of the species assigned to the genus _Ptychohyla_ have ventrolateral glands in the breeding males; furthermore, ventrolateral glands are unknown in other hylids. If the _P. schmidtorum_ group and the _P. euthysanota_ group each evolved from separate hylid stocks, then the ventrolateral glands must have developed independently in both groups. That ventrolateral glands developed independently in five species of frogs in southern México and northern Central America and not in any of the other approximately 500 species of hylids in the world is untenable. It is more logical to assume that the development of the glands took place only once in a stock of hylids that gave rise to the five species herein recognized as members of the genus _Ptychohyla_. Generic Relationships The affinities of _Ptychohyla_ apparently are not with any of the other groups that have been generically separated from _Hyla_. Of the daughter genera in Middle America only _Plectrohyla_ has stream-adapted tadpoles, but these large frogs are not closely related to _Ptychohyla_. Stuart (1954:169) suggested that certain montane species of _Hyla_ in lower Central America and _Hyla salvadorensis_ in El Salvador may be related to _Ptychohyla_ or even congeneric. I have had experience with most of these species in the field and believe that Stuart was correct in his suggestion of relationships. The species concerned are four red-eyed stream-breeding _Hyla_ in Costa Rica--_H. alleei_, _H. legleri_, _H. rufioculis_, and _H. uranochroa_, plus _Hyla salvadorensis_ in the mountains of El Salvador. Morphologically all of the species are similar; _Hyla uranochroa_, _H. legleri_, and _H. rufioculis_ have a lateral white stripe that is expanded to form a spot beneath the eye, as in _Ptychohyla schmidtorum_. The tadpoles of _Hyla rufioculis_ and _H. uranochroa_ have large funnel-shaped mouths and long slender tails like those of _Ptychohyla schmidtorum_. Lips of the tadpoles of _H. legleri_ and _H. salvadorensis_ are folded laterally, in this respect resembling those of the _Ptychohyla euthysanota_ group. I do not know the tadpoles and the breeding call of _Hyla alleei_. The breeding calls of _Hyla rufioculis_ and _H. uranochroa_ consist of high melodious notes; the calls of _H. legleri_ and _H. salvadorensis_ consist of series of short notes that have the general characteristics of the call of _Ptychohyla schmidtorum_. Affinities of the genus _Ptychohyla_ seem to me to be with the red-eyed species forming the _Hyla uranochroa_ group in Costa Rica. All of the species in the _Hyla uranochroa_ group have large frontoparietal fontanelles, rather small ethmoids, and small nasals that are not in contact with one another or with the ethmoid. Some species have a complete quadratojugal-maxillary arch; others do not. Assuming that the parental stock that gave rise both to the _Hyla uranochroa_ group and to _Ptychohyla_ was widespread in Central America at a time of cooler, more humid conditions, it is possible that with subsequent warming temperatures and seasonal rainfall in the lowlands the parental stock was restricted to the Costa Rican highlands, where the _Hyla uranochroa_ group developed, and to the Chiapas-Guatemala highlands, where _Ptychohyla_ evolved. Interspecific Relationships _Ptychohyla schmidtorum_ is thought to resemble more closely the parental stock of the genus than does any other species of _Ptychohyla_ now extant. This parental stock is discussed above in the account of the generic relationships. _Ptychohyla schmidtorum_ has a red eye, white lateral stripe, frontoparietal fontanelle, funnel-shaped mouth in tadpoles, and lacks nuptial spines; in all of these characters it resembles members of the _Hyla uranochroa_ group. Probably during times of glaciation during the Pleistocene, when climates in México and Central America were depressed, the _Ptychohyla_ stock was more widespread than it is now. Subsequent elevation of climatic zones during interglacial periods would have isolated populations as they are today in regions of cloud forests. Thus, through geographic isolation populations could have differentiated and evolved into the present species. Climatic fluctuation in the Pleistocene must have been of sufficient magnitude to permit the spread of cool, moist forests containing _Ptychohyla_ across the Isthmus of Tehuantepec into the mountains of Oaxaca. Because of its small nuptial spines, small triangular vomers, coloration, and absence of a rostral keel, _Ptychohyla euthysanota_, more than any of the other species in the _P. euthysanota_ group, resembles _P. schmidtorum_. At the present time _P. euthysanota_ and _P. schmidtorum_ are sympatric. As I have mentioned previously, ecological segregation and interspecific competition probably is highly developed in the tadpoles of _Ptychohyla_. If this ecological segregation resulted from intraspecific competition in a stock of _Ptychohyla_, possibly _P. euthysanota_ and _P. schmidtorum_ differentiated sympatrically in this way. Specific identity is maintained, at least in part, by different breeding calls in males. _Ptychohyla spinipollex_ and _P. leonhardschultzei_ seem to be more closely related to one another than either is to _P. euthysanota_. Probably a stock of _P. euthysanota_ was isolated on the Atlantic slopes of northern Central America from _P. euthysanota_ on the southern slopes. The frogs on the Atlantic slopes differentiated and spread into the mountains of Oaxaca, where through isolation by the barrier of the Isthmus of Tehuantepec they developed into _P. leonhardschultzei_, while the stock on the northern slopes of Central America evolved into _P. spinipollex_. Subsequent to the differentiation of _P. leonhardschultzei_ and _P. spinipollex_ from _P. euthysanota_ and during a time of cooler more equable climate than exists now, _P. euthysanota_ and _P. schmidtorum_ invaded the Central Highlands of Chiapas. Subsequent climatic changes isolated populations of each in the Central Highlands, where _P. euthysanota macrotympanum_ and _P. schmidtorum chamulae_ evolved. _Ptychohyla ignicolor_ probably represents stock of _P. schmidtorum_ that crossed the Isthmus of Tehuantepec and became isolated in Oaxaca on the western side of the isthmus. LITERATURE CITED AHL, E. 1934. Über eine sammlung von Reptilien und Amphibien aus Mexiko, Zool. Anz., 106:184-186, April 15. BLAIR, W. F. 1956. Call difference as an isolation mechanism in southwestern toads (genus _Bufo_). Texas Jour. Sci., 8:87-106, March. DUELLMAN, W. E. 1956. The frogs of the hylid genus _Phrynohyas_ Fitzinger, 1843. Misc. Publ. Mus. Zool. Univ. Michigan, 96:1-47, pls. 1-6, February 21. 1960. Synonymy, variation, and distribution of _Ptychohyla leonhardschultzei_ Ahl. Studies of American Hylid Frogs, IV. Herpetologica, 16:191-197, September 23. 1961. Descriptions of two species of frogs, genus Ptychohyla. Studies of American Hylid Frogs, V. Univ. Kansas Publ. Mus. Nat. Hist., 13:349-357, pl. 25, April 27. FOUQUETTE, M. J. 1960. Isolating mechanisms in three sympatric treefrogs in the Canal Zone. Evolution, 14:484-497, December. KELLOGG, R. 1928. An apparently new _Hyla_ from El Salvador. Proc. Biol. Soc. Washington, 41:123-124, June 29. MERTENS, R. 1952. Die Amphibien und Reptilien von El Salvador. Senckenbergischen Naturf. Gesell., 487:1-120, pls. 1-16, December 1. RIDGWAY, R. 1912. Color standards and color nomenclature. Washington, D. C., 44 pp., 53 pls. SHANNON, F. A. 1951. Notes on a herpetological collection from Oaxaca and other localities in Mexico. Proc. U. S. Nat. Mus., 101:465-484, May 17. STUART, L. C. 1954. Descriptions of some new amphibians and reptiles from Guatemala. Proc. Biol. Soc. Washington, 67:159-178, August 5. TANNER, W. W. 1957. Notes on a collection of amphibians and reptiles from southern Mexico, with a description of a new _Hyla_. Great Basin Nat., 17:52-56, July 31. TAYLOR, E. H. 1937. New species of hylid frogs from Mexico with comments on the rare _Hyla bistincta_ Cope. Proc. Biol. Soc. Washington, 50:43-54, pls. 2-3, April 21. 1942. New tailless amphibia from Mexico. Univ. Kansas Sci. Bull., 28: 67-89, May 15. 1944. A new genus and species of Mexican frogs. Univ. Kansas Sci. Bull., 30:41-45, June 12. 1949. New or unusual Mexican amphibians. Amer. Mus. Novitates, 1437:1-21, December 7. _Transmitted December 27, 1962._ UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY Institutional libraries interested in publications exchange may obtain this series by addressing the Exchange Librarian, University of Kansas Library, Lawrence, Kansas. Copies for individuals, persons working in a particular field of study, may be obtained by addressing instead the Museum of Natural History, University of Kansas, Lawrence, Kansas. There is no provision for sale of this series by the University Library, which meets institutional requests, or by the Museum of Natural History, which meets the requests of individuals. Nevertheless, when individuals request copies from the Museum, 25 cents should be included, for each separate number that is 100 pages or more in length, for the purpose of defraying the costs of wrapping and mailing. * An asterisk designates those numbers of which the Museum's supply (not the Library's supply) is exhausted. Numbers published to date, in this series, are as follows: Vol. 1. Nos. 1-26 and index. Pp. 1-638, 1946-1950. *Vol. 2. (Complete) Mammals of Washington. By Walter W. Dalquest. Pp. 1-444, 140 figures in text. April 9, 1948. Vol. 3. *1. The avifauna of Micronesia, its origin, evolution, and distribution. By Rollin H. Baker. Pp. 1-359, 16 figures in text. June 12, 1951. *2. A quantitative study of the nocturnal migration of birds. By George H. Lowery, Jr. Pp. 361-472, 47 figures in text. June 29, 1951. 3. Phylogeny of the waxwings and allied birds. By M. Dale Arvey. Pp. 473-530, 49 figures in text, 13 tables. October 10, 1951. *4. Birds from the state of Veracruz, Mexico. By George H. Lowery, Jr., and Walter W. Dalquest. Pp. 531-649, 7 figures in text, 2 tables. October 10, 1951. Index. Pp. 651-681. *Vol. 4. (Complete) American weasels. By E. Raymond Hall. Pp. 1-466, 41 plates, 31 figures in text. December 27, 1951. Vol. 5. Nos. 1-37 and index. Pp. 1-676, 1951-1953. *Vol. 6. (Complete) Mammals of Utah, _taxonomy and distribution_. By Stephen D. Durrant. Pp. 1-549, 91 figures in text, 30 tables. August 10, 1952. Vol. 7. Nos. 1-15 and index. Pp. 1-651, 1952-1955. Vol. 8. Nos. 1-10 and index. Pp. 1-675, 1954-1956. Vol. 9. *1. Speciation of the wandering shrew. By James S. Findley. Pp. 1-68, 18 figures in text. December 10, 1955. 2. Additional records and extension of ranges of mammals from Utah. By Stephen D. Durrant, M. Raymond Lee, and Richard M. Hansen. Pp. 69-80. December 10, 1955. 3. A new long-eared myotis (Myotis evotis) from northeastern Mexico. By Rollin H. Baker and Howard J. Stains. Pp. 81-84. December 10, 1955. 4. Subspeciation in the meadow mouse, Microtus pennsylvanicus, in Wyoming. By Sydney Anderson. Pp. 85-104, 2 figures in text. May 10, 1956. 5. The condylarth genus Ellipsodon. By Robert W. Wilson. Pp. 105-116, 6 figures in text. May 19, 1956. 6. Additional remains of the multituberculate genus Eucosmodon. By Robert W. Wilson. Pp. 117-123, 10 figures in text. May 19, 1956. 7. Mammals of Coahulia, Mexico. By Rollin H. Baker. Pp. 125-335, 75 figures in text. June 15, 1956. 8. Comments on the taxonomic status of Apodemus peninsulae, with description of a new subspecies from North China. By J. Knox Jones, Jr. Pp. 337-346, 1 figure in text, 1 table. August 15, 1956. 9. Extensions of known ranges of Mexican bats. By Sydney Anderson. Pp. 347-351. August 15, 1956. 10. A new bat (Genus Leptonycteris) from Coahulia. By Howard J. Stains. Pp. 353-356. January 21, 1957. 11. A new species of pocket gopher (Genus Pappogeomys) from Jalisco, Mexico. By Robert J. Russell. Pp. 357-361. January 21, 1957. 12. Geographic variation in the pocket gopher, Thomomys bottae, in Colorado. By Phillip M. Youngman. Pp. 363-387, 7 figures in text. February 21, 1958. 13. New bog lemming (genus Synaptomys) from Nebraska. By J. Knox Jones, Jr. Pp. 385-388. May 12, 1958. 14. Pleistocene bats from San Josecito Cave, Nuevo León, México. By J. Knox Jones, Jr. Pp. 389-396. December 19, 1958. 15. New subspecies of the rodent Baiomys from Central America. By Robert L. Packard. Pp. 397-404. December 19, 1958. 16. Mammals of the Grand Mesa, Colorado. By Sydney Anderson. Pp. 405-414, 1 figure in text, May 20, 1959. 17. Distribution, variation, and relationships of the montane vole, Microtus montanus. By Sydney Anderson. Pp. 415-511, 12 figures in text, 2 tables. August 1, 1959. 18. Conspecificity of two pocket mice, Perognathus goldmani and P. artus. By E. Raymond Hall and Marilyn Bailey Ogilvie. Pp. 513-518, 1 map. January 14, 1960. 19. Records of harvest mice, Reithrodontomys, from Central America, with description of a new subspecies from Nicaragua. By Sydney Anderson and J. Knox Jones, Jr. Pp. 519-529. January 14, 1960. 20. Small carnivores from San Josecito Cave (Pleistocene), Nuevo León, México. By E. Raymond Hall. Pp. 531-538, 1 figure in text. January 14, 1960. 21. Pleistocene pocket gophers from San Josecito Cave, Nuevo León, México. By Robert J. Russell. Pp. 539-548,1 figure in text. January 14, 1960. 22. Review of the insectivores of Korea. By J. Knox Jones, Jr., and David H. Johnson. Pp. 549-578. February 23, 1960. 23. Speciation and evolution of the pygmy mice, genus Baimoys. By Robert L. Packard. Pp. 579-670, 4 plates, 12 figures in text. June 16, 1960. Index. Pp. 671-690 Vol. 10. 1. Studies of birds killed in nocturnal migration. By Harrison B. Tordoff and Robert M. Mengel. Pp. 1-44, 6 figures in text, 2 tables. September 12, 1956. 2. Comparative breeding behavior of Ammospiza caudacuta and A. maritima. By Glen E. Woolfenden. Pp. 45-75, 6 plates, 1 figure. December 20, 1956. 3. The forest habitat of the University of Kansas Natural History Reservation. By Henry S. Fitch and Ronald R. McGregor. Pp. 77-127, 2 plates, 7 figures in text, 4 tables. December 31, 1956. 4. Aspects of reproduction and development in the prairie vole (Microtus ochrogaster). By Henry S. Fitch. Pp. 129-161, 8 figures in text, 4 tables. December 19, 1957. 5. Birds found on the Arctic slope of northern Alaska. By James W. Bee. Pp. 163-211, plates 9-10, 1 figure in text. March 12, 1958. *6. The wood rats of Colorado: distribution and ecology. By Robert B. Finley, Jr. Pp. 213-552, 34 plates, 8 figures in text, 35 tables. November 7, 1958. 7. Home ranges and movements of the eastern cottontail in Kansas. By Donald W. Janes. Pp. 553-572, 4 plates, 3 figures in text. May 4, 1959. 8. Natural history of the salamander, Aneides hardyi. By Richard F. Johnston and Gerhard A. Schad. Pp. 573-585. October 8, 1959. 9. A new subspecies of lizard, Cnemidophorus sacki, from Michoacán, México. By William E. Duellman. Pp. 587-598, 2 figures in text. May 2, 1960. 10. A taxonomic study of the middle American snake, Pituophis deppei. By William E. Duellman. Pp. 599-610, 1 plate, 1 figure in text. May 2, 1960. Index. Pp. 611-626. Vol. 11. Nos. 1-10 and index. Pp. 1-703, 1958-1960. Vol. 12. 1. Functional morphology of three bats: Sumops, Myotis, Macrotus. By Terry A. Vaughan. Pp. 1-153, 4 plates, 24 figures in text. July 8, 1959. *2. The ancestry of modern Amphibia: a review of the evidence. By Theodore H. Eaton, Jr. Pp. 155-180, 10 figures in text. July 10, 1959. 3. The baculum in microtine rodents. By Sydney Anderson. Pp. 181-216, 49 figures in text. February 19, 1960. *4. A new order of fishlike Amphibia from the Pennsylvanian of Kansas. By Theodore H. Eaton, Jr., and Peggy Lou Stewart. Pp. 217-240, 12 figures in text. May 2, 1960. 5. Natural history of the bell vireo. By Jon C. Barlow. Pp. 241-296, 6 figures in text. March 7, 1962. 6. Two new pelycosaurs from the lower Permian of Oklahoma. By Richard C. Fox. Pp. 297-307, 6 figures in text. May 21, 1962. 7. Vertebrates from the barrier island of Tamaulipas, México. By Robert K. Selander, Richard F. Johnston, B. J. Wilks, and Gerald G. Raun. Pp. 309-345, pls. 5-8. June 18, 1962. 8. Teeth of Edestid sharks. By Theodore H. Eaton, Jr. Pp. 347-362, 10 figures in text. October 1, 1962. More numbers will appear in volume 12. Vol. 13. 1. Five natural hybrid combinations in minnows (Cyprinidae). By Frank B. Cross and W. L. Minckley. Pp. 1-18. June 1, 1960. 2. A distributional study of the amphibians of the Isthmus of Tehuantepec, México. By William E. Duellman. Pp. 19-72, pls. 1-8, 3 figures in text. August 16, 1960. 3. A new subspecies of the slider turtle (Pseudemys scripta) from Coahulia, México. By John M. Legler. Pp. 73-84, pls. 9-12, 3 figures in text. August 16, 1960. 4. Autecology of the copperhead. By Henry S. Fitch. Pp. 85-288, pls. 13-20, 26 figures in text. November 30, 1960. 5. Occurrence of the garter snake, Thamnophis sirtalis, in the Great Plains and Rocky Mountains. By Henry S. Fitch and T. Paul Maslin. Pp. 289-308, 4 figures in text. February 10, 1961. 6. Fishes of the Wakarusa river in Kansas. By James E. Deacon and Artie L. Metcalf. Pp. 309-322, 1 figure in text. February 10, 1961. 7. Geographic variation in the North American cyprinid fish, Hybopsis gracilis. By Leonard J. Olund and Frank B. Cross. Pp. 323-348, pls. 21-24, 2 figures in text. February 10, 1961. 8. Descriptions of two species of frogs, genus Ptychohyla; studies of American hylid frogs, V. By William E. Duellman. Pp. 349-357, pl. 25, 2 figures in text. April 27, 1961. 9. Fish populations, following a drought, in the Neosho and Marais des Cygnes rivers of Kansas. By James Everett Deacon. Pp. 359-427, pls. 26-30, 3 figs. August 11, 1961. 10. Recent soft-shelled turtles of North America (family Trionychidae). By Robert G. Webb. Pp. 429-611, pls. 31-54, 24 figures in text, February 16, 1962. Index. Pp. 613-624. Vol. 14. 1. Neotropical bats from western México. By Sydney Anderson. Pp. 1-8. October 24, 1960. 2. Geographic variation in the harvest mouse. Reithrodontomys megalotis, on the central Great Plains and in adjacent regions. By J. Knox Jones, Jr., and B. Mursaloglu. Pp. 9-27, 1 figure in text. July 24, 1961. 3. Mammals of Mesa Verde National Park, Colorado. By Sydney Anderson. Pp. 29-67, pls. 1 and 2, 3 figures in text. July 24, 1961. 4. A new subspecies of the black myotis (bat) from eastern Mexico. By E. Raymond Hall and Ticul Alvarez. Pp. 69-72, 1 figure in text. December 29, 1961. 5. North American yellow bats, "Dasypterus," and a list of the named kinds of the genus Lasiurus Gray. By E. Raymond Hall and J. Knox Jones, Jr. Pp. 73-98, 4 figures in text. December 29, 1961. 6. Natural history of the brush mouse (Peromyscus boylii) in Kansas with description of a new subspecies. By Charles A. Long. Pp. 99-111, 1 figure in text. December 29, 1961. 7. Taxonomic status of some mice of the Peromyscus boylii group in eastern Mexico, with description of a new subspecies. By Ticul Alvarez. Pp. 113-120, 1 figure in text. December 29, 1961. 8. A new subspecies of ground squirrel (Spermophilus spilosoma) from Tamaulipas, Mexico. By Ticul Alvarez. Pp. 121-124. March 7, 1962. 9. Taxonomic status of the free-tailed bat, Tadarida yucatanica Miller. By J. Knox Jones, Jr., and Ticul Alvarez. Pp. 125-133, 1 figure in text. March 7, 1962. 10. A new doglike carnivore, genus Cynaretus, from the Clarendonian Pliocene, of Texas. By E. Raymond Hall and Walter W. Dalquest. Pp. 135-138, 2 figures in text. April 30, 1962. 11. A new subspecies of wood rat (Neotoma) from northeastern Mexico. By Ticul Alvarez. Pp. 139-143. April 30, 1962. 12. Noteworthy mammals from Sinaloa, Mexico. By J. Knox Jones, Jr., Ticul Alvarez, and M. Raymond Lee. Pp. 145-159, 1 figure in text. May 18, 1962. 13. A new bat (Myotis) from Mexico. By E. Raymond Hall. Pp. 161-164, 1 figure in text. May 21, 1962. 14. The mammals of Veracruz. By E. Raymond Hall and Walter W. Dalquest. Pp. 165-362, 2 figures. May 20, 1963. 15. The recent mammals of Tamaulipas, México. By Ticul Alvarez. Pp. 363-473, 5 figures in text. May 20, 1963. More numbers will appear in volume 14. Vol. 15. 1. The amphibians and reptiles of Michoacán, México. By William E. Duellman. Pp. 1-148, pls. 1-6, 11 figures in text. December 20, 1961. 2. Some reptiles and amphibians from Korea. By Robert G. Webb, J. Knox Jones, Jr., and George W. Byers. Pp. 149-173. January 31, 1962. 3. A new species of frog (Genus Tomodactylus) from western México. By Robert G. Webb. Pp. 175-181, 1 figure in text. March 7, 1962. 4. Type specimens of amphibians and reptiles in the Museum of Natural History, the University of Kansas. By William E. Duellman and Barbara Berg. Pp. 183-204. October 26, 1962. 5. Amphibians and Reptiles of the Rainforests of Southern El Petén, Guatemala. By William E. Duellman. Pp. 205-249, pls. 7-10, 6 figures in text. October 4, 1963. 6. A revision of snakes of the genus Conophis (Family Colubridae, from Middle America). By John Wellman. Pp. 251-295, 9 figures in text. October 4, 1963. 7. A review of the Middle American tree frogs of the genus Ptychohyla. By William E. Duellman. Pp. 297-349, pls. 11-18, 7 figures in text. October 18, 1963. More numbers will appear in volume 15. * * * * * * * Transcriber's Notes. This file was derived from scanned images. With the exception of the list of typographical errors that were corrected below, the original text is presented. In the original, the Plates were grouped together between pages 328 and 329. Here the Illustration: block which contains the text associated with the Plates were moved just above the text in their respective Systematic Account listing. The Plate text contain the notation "× 2" after the caption to let the reader know that the image was enlarged by a factor of two. Typographical Errors Corrected: Several minor typographical corrections were made (missing periods, commas, misspelling of 'and', etc.); but are not indicated here. More substantial changes are listed below: References to the Plate 11 (Audiograms): Pl. 1A, Pl. 1B, etc.=> Pl. 11A, Pl. 11B, etc. Page 301, Paragraph 1: know => known Page 302, Paragraph 1: Zoolegy => Zoology Page 303, Paragraph 5: speces => species Page 305, Paragraph 1: excresences => excrescences Page 308, Paragraph 6: xiphisterum => xiphisternum Page 316, Paragraph 3: with => width Page 327, Paragraph 1: leonhard-schultzei => leonhardschultzei to match remaining report text Page 331, Paragraph 1: skelton => skeleton Publication List Vol. 13, No. 8.: Decriptions => Descriptions