F 
 
 76G 
 S3 
 
ON THE 
 
 OF THE 
 
 EOCENE OF WYOMING, 
 
 BY EDWARD D. .COPE. 
 
 L. -y 
 
 (Read before the American Philosophical Society, February 21, 1873.) 
 

 m/f 
 
 ON THE SHORT FOOTED UNGULATA OF THE EOCENE OF 
 
 WYOMING. 
 
 BY EDWARD D. COPE. 
 
 (Head before the American Philosophical Society, Feb. 2lst, 1873.) 
 
 In no group of Mammalia have the determinations of palaeontology 
 been more significant than in the Ungulata. Here, in an especial manner, 
 the anticipations of science have been realized, in the filling up of the 
 numerous gaps in the series of living forms. Here especially is it evi- 
 dent, that the existing fauna is but a fragment, and that the faunae of 
 the past, as we know them to-day, are but the precursors of what we may 
 bring to light to-morrow. 
 
 The primary range of variation in the structure of the Ungulata, has 
 been generally admitted by zoologists to be found in the structure of the 
 limbs and feet. Three most prominent types have been distinguished on 
 this basis, viz. : the Artiodactyla, Perissodactyla and the Proboscidia : 
 with some of the lesser importance, those of the Toxodontia and Hyra- 
 coidea* If we direct our attention to the detailed structure of the feet, 
 or of the teeth, each division offers its own range of variation ; witness 
 in the Artiodactyles the differences between the Ruminantia and Omni- 
 vora, and in Perissodactyla, between Equus and RMnocerus. In either 
 order canines and incisors may be present or absent, and molars assume 
 a great variety of patterns of enamel plication. The toes in the latter 
 order may vary from four to one. Nevertheless, the most diverse genera 
 are bound together by intermediate forms, often extinct. Connecting 
 Omnivora and Ruminantia come Oreodon. Merycopotamus, Tragulus, etc. 
 In Perissodactyla, Anchitherium, Palceosyops, etc., connect the extremes. 
 
 The Proboscidians have, on the other hand, remained until recently an 
 isolated group with but few representatives, hence its definition as an 
 order, has been more or less obscured by characters of a special nature, 
 drawn from the dentifion, trunk, etc., which it has been found necessary 
 to omit in characterizing the two orders above mentioned. These charac- 
 ters are so striking in their appearance as to suggest greater systematic 
 importance than belongs to them. Thus the trunk is not more important 
 as a character of the Proboscidia, than it is of the Perissodactyla, where 
 the tapir alone possesses it. Nor are the complex molars and large tusks 
 to be regarded as a definition, for in the Phacochcerus we have molars as 
 compound as in some mastodons, huge canine teeth and no incisors below ; 
 characters very different from many Artiodactyles. Nor can we regard 
 the exclusive union of the astragalus with the navicular a& a final test, for 
 in Perissodactyles the facet for union with the cuboid may be considera- 
 ble (RMnocerus} to almost nothing (Equus}. 
 
 The occasion for this discussion is presented by the discovery by the 
 
 * Vide Gill, Arrangement of the Families of Mammals, Smithson, Misc., Coll., 1872, No. 230; 
 the best analysis of the Mammalia yet published. 
 
palaeontologists of Haydeii's geological surveys of 1871-2, of the remark- 
 able types Bathmodon, UintatJierium, and Eobasileus. These genera con- 
 tradict in several particulars the characters usually assigned to the Pro- 
 boscidia, while they agree with them in others, and they thus present the 
 problem of classification, which will ever recur so long as additions to 
 our knowledge of the life of the past continue to be made. This problem 
 is simply the question as to what characters shall be retained as definitive 
 of natural divisions, on the discovery of intermediate forms. As our 
 system is an expression of the possession of structural characters, our 
 higher groups or orders are naturally expressions of the existence of the 
 more comprehensive characters, or those present through the most ex- 
 tended series of species. Hence we believe them to be also those assumed 
 earliest in time. 
 
 In the case of the Ungulata, the structure of the feet seems to define 
 the greatest range of the species. Thus the Artiodactyla and Perisso- 
 dactyla are digitigrade or unguligrade, while the Proboscidia are nearly 
 plantigrade. The first order exhibits the equal development of the third 
 and fourth toes ; the second of the third toe, while in the Proboscidia the 
 structure is like the last, with more,, numerous digits. But this order 
 differs from both the preceding in the relations of the ulna and radius. 
 In Artiodactyla and Perissodactyla the ulna diminishes greatly distally 
 and presents but a small carpal articular surface obliquely behind that of 
 the much larger radius. In Proboscidia the ulna presents the larger 
 articulation with the carpus, and the radius crosses it obliquely, and pre- 
 sents its articular face alongside of the uliiar. 
 
 The characters of the three orders may be thus stated : 
 
 PKOBOSCIDIA. * 
 
 Feet plantigrade but elevated behind by a plantar pad. Toes nume- 
 rous, short, the middle (3d) largest. Hind limb with knee free from the 
 body ; tibia without spine ; astragalus flat, not produced anteriorly. Fore 
 limb with well developed ulna articulating extensively with the carpus 
 along side of the smaller radius, which crosses it obliquely. 
 
 PERISSODACTYLA. 
 
 Feet digitigrade, with a hock joint. Toes reduced in number, the third 
 largest. Hind limb with knee enclosed in integument of body ; femur 
 with third trochanter ; tibia with spine. Astragalus with pulley-shaped 
 articular face for tibia and anterior prolongation. Fore limb with ulna 
 reduced, its carpal surface smaller than that of the radius, which sup- 
 ports the foot in front of the ulna. 
 
 ARTIODACTYLA. 
 
 Feet digitigrade or unguligrade. Toes reduced, the third and fourth 
 principally and equally developed. Hind limb with knee applied to the 
 side of the body, and elevated hock ; femur without third trochanter ; 
 
 * These characters have been mostly given by Prof. Gill, 1. c. 
 
tibia with large spine. Astragalus with both inferior and anterior 
 pulley-shaped surfaces. Ulna much reduced distally, behind the radius, 
 which includes almost the whole of the carpal articulation. 
 
 This arrangement violates previous views less than any other that 
 would recognize the primary characters of the Eobasil&us. The difficulty 
 of determining the limits of the two first named orders, is partially 
 caused by the fact that the Hyracoidea present the radius of the Proboscidia 
 with the hind foot of the Perissodactyla. These animals are, however, 
 well regarded as a distinct order. Whether all the animals to be included 
 in the Proboscidia possessed a proboscis or not, is of secondary importance. 
 It is neverthele'ss highly probable that Loxolophodon and Eobasileus pos- 
 sessed one, and not unlikely that such forms that approach still nearer 
 the tapirs were not without an organ such as they possess, and which 
 Cuvier ascribed to the PalcBotheria and other allies. 
 
 The divisions of the Proboscidia are as follows : 
 
 No incisors, nasal bones short ; astragalus articulating 
 with navicular only : No third trochanter Proboscidia vera. 
 
 No incisors, nasal bones elongate ; astragalus articu- 
 lating with both navicular and cuboid : No third tro- 
 chanter Dinocerata . 
 
 Dentition complete ; i. e. incisors present ; ? nasal 
 bones. Astragalus articulating with both navicular 
 and cuboid : A rudimental third trochanter Pantodonta.. 
 
 These suborders present a series of approaches to the Perissodactyla. 
 Thus the Dinocerata agree with the typical Proboscidia in addition to the 
 above points, in the posterior expansion of the scapula, and its apical 
 acumination ; in the very short cervical vertebrae ; in the flat carpal 
 bones ; in the absence of pit for round ligament of the femur ; in the flat- 
 tened great trochanter, contracted condyles, and fissure-like intercondylar 
 fossa of the same bone. In the longitudinal crest of the tibia separating 
 glenoid articular faces which are on a transverse line. In the short cal- 
 caneum which is wider than long, and tubercular on the inferior face. 
 In the five digits ; the acetabulum not separated by a peduncle from 
 the iliac plates, and the lack of angular production of the latter beyond 
 the sacrum. Also in the three distinguished sacral vertebrae, as con- 
 trasted with the five closely coossified ones of the Rhinocerotidce. These 
 characters are, some of them, of subordinate value only. 
 
 The chief differences are seen in the cranium, though here also there 
 are important resemblances. Thus in Loxolopliodon the malar bone forms 
 the middle element of the zygomatic arch, sending a narrow strip only for- 
 ward to the neighborhood of the lachrymal. In Uintatherium, accord- 
 ing to Marsh, its extension towards the side of the face is rather greater, 
 but still much less than in Perissodactyla. The dentition is not far 
 removed from that of Dinotherium, and the mode of succession of the 
 teeth was in all probability similar. The premaxillaries and nasals are 
 
4 
 
 excavated and exostosed for the attachment of a trunk in LoxolopJwdon. 
 The lateral and occipital crests of the cranium, though different from 
 the enlarged sinuses of the diploe of Elephants, represent the external 
 walls of this structure, and furnish a hint as to its mode of origin, and 
 serve to ease the transition to Perissodactyles. 
 
 The differences in the cranium are consequent upon its anterior elonga- 
 tion, the nasal bones and premaxillaries becoming thus much extended. 
 The lachrymal is perforated by a small lachrymal canal in Uintatherium, 
 according to Marsh, but excavated on the margin only in LoxolopJwdon. 
 It is neither in Elephas. There is a postglenoid process more largely 
 developed than in Proboscidia vera. Other differences of still less import- 
 ance are to be seen in the anterior position of the exterior nares, and 
 the presence of horns. 
 
 The Pantodonta are represented by Bathmodon. With a structure of 
 the hinder limb "nearly resembling Eobasileus, we have more pronounced 
 relationships to the Perissodactyles. The scapula has the massive 
 apical acuminatiou of the Proboscidia vera, and there is no round ligament 
 of the femur in some of them. The astragalus has the same flattened 
 form seen in Uintatherium and is even less like that of the Perissodac- 
 'tyla. The type of molars and the long compressed canines are similar to 
 those of Loxolophodon. On the other hand, the cervical vertebrae are 
 rather longer, and there is a rudimental third trochanter of the femur. 
 
 History, etc. I originally referred the Eobasileidw to the Proboscidia, 
 on account of the structure of the limbs, and subsequently stated a num- 
 ber of reasons for this conclusion at a meeting of the Academy Natural 
 Sciences of Philadelphia, held January 14th, 1873 (published January 
 16th). In' the present paper, numerous confirmatory characters are 
 added. The Bathmodontidce I have heretofore referred to the Perisso- 
 dactyla. 
 
 Prof. Marsh, in describing a species of this group, TitanotJierium 
 f anceps (July, 1871), compares it with perissodactyle species, and in de- 
 scribing the tibia says, that it "at its proximal end, has the femoral sur- 
 faces contiguous, with no prominent elevation between them, resembling 
 in this respect some of the Proboscidea. " A few days before the publi- 
 cation of my conclusions, in a foot-note (July 22d, 1872), he altered the 
 name Titanotkerium to Mastodon, indicating that he had reached the 
 same opinion. Shortly after (Amer. Journ. Sci. Arts, Sept. 27th), he 
 altered his view, constructing a supposed new order " Dinocerata," for 
 their reception. 
 
 As regards the name of the order here defined as including the three 
 suborders above mentioned, I have preferred using one already employed 
 to coining a new one. This is the better course also, if, as is not unlikely, 
 the distinctions on which it, as well as the oiher two orders repose, shall 
 be broken down by new discoveries in paleontology. 
 
5 
 
 DlNOCERATA. 
 
 The genera of this* group known to the writer are four, which differ 
 as follow : 
 
 1. Nasal bones with flat horizontal horn-cores overhanging their apex. 
 Cervical vertebrae short ; malar bone much reduced in 
 
 front Loxolophodon. 
 
 2. Nasal bones with small tuberosities. 
 
 Cervical vertebrae short Bohasileua. 
 
 Cervical vertebrae longer; the malar bone reaching maxil- 
 lary face Uimatherium. 
 
 3. Nasal bones without the anterior horn-cores. 
 
 Cervicals ? Megacer-atops. 
 
 The dentition of this group requires special notice. Judging from the 
 relative sizes of the teeth, I have written the molar series of Loxoloplio- 
 don 4 2, but judging from the forms of the crowns, it should be 1 5. 
 However this should be, I have no doubt that as in other Proboscidia the 
 premolar and not the molar series is deficient, and that there are three 
 or four true molars at least. In a mandible found alone, which agrees in 
 size with some species of Uintatlierium, six molars are preserved. Of 
 these the posterior two display three sub-transverse crests, of which the 
 anterior two form a chevron with open apex directed to the inside. An- 
 terior to the front crest is a cingular tubercle. The symphyseal part of 
 the jaw is remarkable : it is coossified, exceedingly compressed, and 
 curved upwards so as to resemble slightly the narrow prow of a South 
 Sea boat. There are two teeth on each side, which are separated from 
 the molars by a diastema. They are much compressed and curved up- 
 wards and forwards, and the anterior pair issue from the jaw in contact. 
 The crowns are lost in the specimen. The determination of these teeth 
 is facilitated by the presence of the mental foramen below the posterior 
 one. This foramen issues, as is well known, posterior to the canines in 
 all mammalia, and either below premolars, or the diastema. The two 
 teeth in our fossil will then be premolar and canine respectively, and the 
 incisors must be regarded as wanting. This is in conformity with the 
 structure of the upper jaw, and is rendered probable by the great reduc- 
 tion of the symphysis of the lower jaw in the species. It is also suggested 
 by the almost universal tendency to reduction of the incisors seen in the 
 mammals of the same extinct fauna. In Bathmodon and Palceosyops the 
 canines are thrown into the incisor series as in Ruminantia, and in Palcc- 
 osyops the outer incisors are much reduced. In several genera there are 
 but two incisors. Finally in Synoplotherium, and probably*in Anchipho- 
 dus, the large inferior teeth described by Dr. Leidy and myself as in- 
 cisors and which resemble the cutters of Rodentia, are immediately in 
 front of the mental foramen, and bear the same relation to it and to the 
 premolar teeth, as do the canines of Palceosyopa and other mammalia. 
 Hence I believe these to be canines, and that the inferior incisors are 
 
wanting. The probability of the truth ol this determination is increased 
 by the presence of a small interval between them, and by the fact that 
 they oppose the canines of the upper jaw. 
 
 LOXOLOPHODON. Cope. 
 
 Proceedings American Philosophical Society, 1872, p. 580, extra copies 
 
 published August 19th ; and p. 488 (Aug. 22d). 
 
 The cranium in this genus is very elongate and compressed. The 
 muzzle is posteriorly roof-shaped, but is anteriorly concave and flattened 
 out into a bi-lobed shovel which rises above the extremity of the bone. 
 This extremity is subconic, and short and decurved. A second pair of 
 horn-cores stands above the orbits ; each one composed externally of the 
 maxillary bone, and internally of an upward extension of the posterior 
 part of the nasal. Behind this horn the superior margin of the temporal 
 fossa sinks, but rises again at its posterior portion, probably above the 
 level of the middle of the parietal bones. This portion of the skull is 
 injured in my only specimen. The occipital rises in a wall upwards from 
 the foramen magnum, and supports, probably a little in front of the junc- 
 tion with the superior and inferior ridges bounding the temporal fossa, a 
 third horn core on each side. The base of this core is as stout as that 
 above the orbit, and sub-cylindric in section. The temporal fossa has its 
 principal extent posterior to the zygomatic arch, and is in form like a 
 trough, the inferior edge being recurved from the squamosal process to 
 the summit of the occipital crest. It is narrow within the zygomatic 
 arch, which is short, enclosing a space whose length is less than one- 
 fourth that of the cranium. 
 
 The occipital bone extends but a short distance on each side of the 
 condyles, and is separated from the mastoid by an irregular suture, 
 which is pierced by a large mastoid foramen. On the inferior face near 
 to each condyle and one-third the distance from its inner extremity, is a 
 posterior condyloid foramen, isolated by a narrow bar from the extremity 
 of the foramen lacerum posterius. The paramastoid process is repre- 
 sented by a small tuberosity, and the mastoid by a rather larger one, 
 some distance anterior to it. 
 
 The meatus auditorius opens upwards just below the external ridge of 
 the temporal fossa and at a little distance behind the post-glenoid pro- 
 cess. Its canal contracts rapidly, and extends upwards and backwards 
 towards the labyrinth. It is separated from the foramen lacerum by but 
 a thin wall, and if there was an expansion of the cavum tympam, it must 
 have been exceedingly small, owing to the close approximation of the 
 mastoid to ttie basi-occipital and sphenoid at this point. The labyrinth 
 is lodged in a petrous mass opposite the occipito-mastoid suture, and the 
 canals are small. 
 
 The basi-occipital contracts anteriorly, and with the sphenoid forms an 
 uninterrupted boundary of the foramen lacerum. This terminates oppo- 
 site to the posterior boundary of the external meatus. and gives rise to a 
 
wide shallow groove which extends anteriorly between the pterygoid 
 ala and the postglenoid process, and turning outwards round the latter, 
 grooves it. Opposite to the postglenoid process and just posterior to the 
 end of the pterygoid a small foramen enters, which is probably the for- 
 amen ovale. Almost continuous with it is a canal which pierces the base 
 of the pterygoid longitudinally, and issues in an excavation of its exter- 
 nal face near the sphenoid. 
 
 The pterygoids are remarkable for their great length, enclosing as they 
 do with the palatine processes, a deep, narrow, trench-like fossa, which 
 measures almost the entire length of the zygomatic fossa. Processes of 
 the sphenoid contribute to these walls (which are thus double), and the 
 sphenoid roof is strongly concave. The alisphenoid is elongate antero- 
 posteriorly, and is principally in contact superiorly with the frontal; an- 
 teriorly it has a short suture with the lachrymal. Almost its entire length 
 is traversed by a shallow groove which terminates in a small foramen 
 opticum, opposite to a point marking the posterior third of the zygomatic 
 fossa. The foramen rotundum issues as usual between the alisphenoid 
 and the pterygoid, but is' considerably anterior, as well as inferior to the 
 /. opticum. I cannot determine whether the orbitosphenoid is distinct. 
 
 The lachrymal is a large bone of a triangular outline, the shorter 
 side being inferior. It is entirely on the inner face of the orbit, and 
 as in the elephant, separates the frontal and maxillary by its superior 
 prolongation. Its inferior border is slightly notched in front by the 
 large foramen infraorbitale posterius, and the anterior is deeply emargi- 
 nate, passing behind the small/, lachrymale. 
 
 The palate is remarkable for its length and narrowness. Its roof is 
 chiefly composed of the maxillaries, but a very short portion is formed by 
 the palatine plates of the o. o. palatina. These are produced into a 
 median point behind between the nares, and exteriorly form the inner 
 wall of the postnareal trough for a considerable distance. The maxil- 
 laries also form the outer wall for a short distance, being produced in a 
 contracted form behind the molar teeth. The two bones enclose a small 
 foramen in this prolongation, and a larger one on the anterior suture of 
 the palatine, the foramen palatinum. The palate is deeply concave 
 anteriorly. There is an elongate foramen close to the alveolus of the first 
 premolar, extending anterior to it. The premaxillaries are longitudinal 
 and separated anteriorly for two-fifths of their length, by a large foramen 
 incisivum, which they do not enclose. They extend on the side of the 
 muzzle into an acute angle upwards and backwards and are prolonged 
 forwards above the exterior nares, which the suture reaphes by an 
 abrupt descent. The maxillary supports the malar on a posteriorly 
 directed process which reaches to the end of the anterior third of the 
 arch below, half that distance on the side, and is bordered by a narrow 
 strip of the malar on the inner side, as far as the anterior boundary of 
 the orbit. The premaxillaries do not enclose the very large foramen in- 
 cisivum in front, and are therefore deeply furcate. 
 
8 
 
 The dentition is I. ; C. 1 ; P. M. 4 ; M. 2. The canine is a tusk of 
 compressed form with anterior and posterior cutting edges, and a strong 
 posterior curvature. Its fang is embraced one-third by the premaxillary 
 bone, and is enclosed in a rib-like swelling of the side of the cranium, 
 which extends upwards and backwards. The premolars are well worn, 
 and have transverse cordate surfaces of attrition. These have probably 
 resulted from the wearing down of a chevron of two crests converging 
 inwards, in some with an inner tubercle. On the molars this crescent is 
 represented by a V, with the apex inwards ; on the last, the inner tuber- 
 cle is at one side (the posterior) of the apex. 
 
 Name. I first applied the name Loxolopliodon to this genus in a short 
 paper published August 19, 1872, as above cited, with a diagnostic de- 
 scription ; the L. cornutus was there cited as the first species, and is here 
 retained as the type. I again described it more fully in a paper published 
 August 22d, citing Eolasileus (August 20th) as a synonym, in which I 
 was in error, as indicated by the present paper. The same nomenclature 
 was employed in a paper read before the American Association for the 
 Advancement of Science, held at Dubuque, commencing August 23, 1872. 
 
 In the paper of August 22d, I regarded this genus as identical with 
 that to which I had previously (February 16, 1872) applied the name 
 Loxolophodon, and included in it the species there called Bathmodon 
 (Loxolophodon} semicinctus, Cope. With further material this appears 
 not to be correct ; the Bathmodon semicinctus belongs truly to that 
 genus, and is very near to the B. radians, so that the name Loxolophodon 
 becemes a synonym in this connection, and may be used again for the 
 present genus without interference. 
 
 LOXOLOPHODON CORNUTUS. Cope. 
 
 Loxolophodon cornutus, Cope. Proceedings American Philosophical 
 Society, 1872, p. 580 (August 19th), 1. c. 1872, p. 488 (August 22d). 
 Eobasileus cornutus, Cope, American Naturalist, 1872, p. 774. 
 
 Established on the remains of a single individual, which consist of a 
 nearly perfect cranium, the right scapula complete, several vertebra 
 including the sacral, the first or second rib, the pelvis complete, and the 
 entire right femur ; also probably the proximal end of a radius. 
 
 The species is remarkable for the narrow form of the cranium, its 
 width at the middle being one-fourth its length. A little in front of the 
 middle, are situated the horn-cores. These diverge, the upper portion 
 having an outward curvature. The base of each is triangular with 
 obtuse angles in section, and the inner angle is the section of a rib-like 
 projection which extends across the middle line to its fellow and rises 
 half way up the horn-core. Above its rather abrupt termination, the 
 core is transversely compressed, with oval obtuse apex. The core 
 measures M. .240 (9.5 inches) from its base in front, M. .108 (4.25 inches) in 
 width at the base behind, and .077 (3 inches) in diameter at the apex. A 
 slight swelling of the sides of the muzzle descends obliquely forwards 
 
9 
 
 from the base of each horn, which enlarges below into a prominent rib, 
 which encloses the alveolus of the canine tusk. In front of the horns 
 the muzzle is roof-like ; anteriorly it flattens out, and swells a little 
 above the posterior end of the nasal meatus. In front of this it expands 
 again, and rises gently to the extremity of the bi-lobed nasal shovel, which 
 overhangs the premaxillaries, the nasal meatus and the greater part of 
 the apex of the nasal bones. The latter is short and with a wide base and 
 resembles two lateral cones flattened together, their extremities obliquely 
 truncate outwards and excavated. The composition of the upper surface 
 of the cranium is somewhat difficult to determine, owing to the injured 
 state of the posterior part. If we regard the bone which bounds the 
 lachrymal behind and above, as frontal, as I did in originally describing 
 the species, it gives an extraordinary extent to the nasals, for the com- 
 mon suture of these bones extends Y-shaped backwards, to a point 
 opposite to the middle of the zygomatic arches. It gives to the nasals 
 an extent equal to that of the frontals and parietals combined. They 
 not only support the anterior shovels but form the inner half of the 
 median horn-cores, rising as high as the tuberosity above described. To 
 regard these bones as frontals would involve the improbable peculiarity 
 of their extending beyond the nareal orifices, and the terminal cone of 
 the nasals is not separated from them by suture. The question is decided 
 in favor of their being nasals, by those bones as preserved in Eobasileus 
 pressicorniSj Cope, where the shovel is represented by a tubercle only on 
 the side of a continuous nasal. The immense -length of the snout in Loxo- 
 loplwn looks as though the nasal bones had extended themselves for- 
 ward, so as to ossify the basal portions of an elephantine proboscis. 
 
 The frontals descend behind the horns, with a very obtuse or rounded 
 continuation, to the inner side of the fossa, and without any superciliary 
 margin. They form with the posterior part of the nasals a shallow me- 
 dian basin. The suture with the parietals is very indistinct, but if I 
 have truly discovered it, it forms another posteriorly directed chevron, 
 and leaves but a narrow superciliary portion of the frontals. Above the 
 postglenoid processes the parietals rise again to the transverse occipital 
 crest, but to what height is uncertain. At the mastoid region, the 
 cranium widens a little, and is excavated at the sides by the temporal 
 fossae. Near where the lateral and posterior crests join the inferior ridge- 
 like border of the temporal fossa, in front of a position occupied by a 
 knob in E. pressicornis, is a strong horn-core with sub-cylindric base. 
 It stands obliquely backwards towards the junction of the inferior 
 squamosal and transverse crests, and is connected to these by an oblique 
 ridge, one side of which is marked with irregular, short, longitudinal 
 rugosities. At the base of these elevations are three sinuses. This por- 
 tion was found close to the skull, but separated from it, and the precise 
 mode of its attachment has not been discovered by actual fit. 
 
 The occiput rises upwards for four inches above the condyles; perhaps 
 it displayed a posteriorly sloping transverse crest as in E. pressicorms. 
 
10 
 
 The paramastoid and mastoid tuberosities are narrowed and extend ob 
 liquely downwards and forwards. The lower part of the exoccipital 
 suture runs along a ridge, and there is a tuberosity in front of the mas- 
 toid foramen. An irregular A-shaped crest extends upwards with the 
 apex at the inferior temporal crest, and its anterior limb forming part of 
 the posterior boundary of the meatus auditorium. The inferior temporal 
 crest is directed outwards below, but forwards above. 
 
 The narrowness of the cranium is readily seen on comparing the 
 postglenoid processes. These are not deep, but have considerable trans- 
 verse extent, and are separated by a space only a little greater than the 
 transverse diameter of each. The zygomatic arches are compressed pos- 
 teriorly with crest-like superior ridge, but rounded above anteriorly. 
 There is not the least trace of posterior boundary of the orbit. The 
 squamosal process overlaps the malar bone extensively, terminating in a 
 point, the latter ending obtusely. The malar is supported in front by a 
 maxillary process, which is united with it by a zigzag suture on the outer 
 face and a squamosal one within and below. The foramen infraorbitale 
 exterius is large, and issues a short distance in front of the orbit, not so 
 near it as in the elephants. From this point to the ridge enclosing the 
 canine alveolus the side of the maxillary bone is deeply concave, and the 
 palatal surface correspondingly contracted. The bone is continued up- 
 wards and outwards as the external part and apex of the middle horn- 
 cores. Anteriorly it is bounded by the premaxillary to a point as far 
 anterior to the base of the horn as the width of the latter; behind that 
 point it is in contact with the nasals. The premaxillary is prolonged 
 upwards and backwards into a narrow tongue. Its inferior portion is 
 convex above on each side, concave below, with projecting alveolar bor- 
 ders, which are flat and slightly concave fore and aft. The extremity of 
 each is rugose below, supports a prominent tubercle medially and a 
 smaller one at the superior angle. 
 
 The exterior nares are not separated by osseous septum. Their lateral 
 border is marked on the inferior surface of the nasal and premaxillary 
 roof, by a curved ridge or crest, which converge forwards and bound the 
 interior concavity of the roof. They gave support to muscular or liga- 
 mentous attachments. The posterior angle of the nares is abruptly ex- 
 cavated with thickened walls. The palate is remarkably narrow, and 
 is most deeply excavated between the alveolae of the tusks, or at the 
 maxillo-premaxillary suture. From near this point to the palatine suture 
 a low but sharp crest extends along the middle line. The width of the 
 palate at the diastema is one ninth of its length. The diastema is more 
 than half the length of the molar series. The pterygoid process of the 
 palate has two convergent grooves on its inferior surface. ^ 
 
 The teeth are remarkable for the extent of the exposure of their slender 
 roots, as well as their very small size a's compared with the size of the 
 animal. The tusk is slightly turned outwards at the tip and the inner 
 face is worn by attrition with some opposing tooth for one-third its length 
 
11 
 
 on the posterior third. The superior margin of the enamel on this side 
 is chevron-shaped, the apex being only one-third the length from the 
 extremity. It extends further upwards in front and on the outer side, but 
 is worn in an oval patch at the apex of the chevron of this side by contact 
 with the inferior teeth, as above described. The enamel is smooth 
 behind, rugose in front. The apex contracts regularly to a flattened 
 obtuse point. The fang is hollow for about half its length. The 
 enamel of the molars is nearly smooth. Each one has a strong cingu- 
 lum fore and aft, which is discontinued on the inner and outer faces ex- 
 cept in P. M. 1, and M. 2. In the former, it is continued on the outer 
 side at the base of the concavity of the exterior face; on the latter, it is 
 continued round the inner side. The grinding surface of the P. M. 1, 
 is tripodal, and probably composed of a worn crescent and inner tubercle. 
 The others are transverse arrow-shaped; the P. M. 4 is much more worn 
 than the others. M. 2 is larger than M. 1. Its oblique crests have evi- 
 dently been worn from before. All the molars have three roots, but the 
 posterior pair are united for part of their length in all. 
 
 The corner does not unite with the superior crest of the palatine 
 bones. The sphenoid flattens out behind the post-nareal trough and is 
 coosified with the basioccipital. The latter is marked by two oval sur- 
 faces at the place of suture, with a slight prominence between. No 
 lower jaw was found with this specimen, but from the contraction of 
 the parts opposed to it, it was evidently very small. 
 
 Cranial Measurements. 
 
 M. 
 Length from end nasals to end occipital condyle (3 
 
 feet 1.5 inches) 0.930 
 
 Width just behind end nasal shovels 192 
 
 " in front of horns .132 
 
 " at base of horns in front 205 
 
 " behind horns at apex of frontal suture 185 
 
 " above posterior edge meatus auditorium 310 
 
 " between apices horn-cores 370 
 
 " basis supraoccipital horn-core 100 
 
 " including zygomatic arches (greatest) 320 
 
 Length of nasal bones to ridge between horn-cores. . . .410 
 
 " " " " " frontal suture 540 
 
 " of zygomatic fossa above 230 
 
 " from angle iiares to end shovel 205 
 
 " " " " premaxillary 155 
 
 " from end premaxillary to basis of camine 120 
 
 " " " " " P.M.I 276 
 
 " of molar series 185 
 
 " of palate 450 
 
 " of pterygo-palatine crest 200 
 
 " of sphenoid axis 185 
 
 " " basioccipital (with condyles) 128 
 
12 
 
 M. 
 
 Width between tips premaxillaries 070 
 
 " at canine alveoli 185 
 
 " between canine alveoli 080 
 
 " at diastema 050 
 
 " between last molars '070 
 
 " pterygo-palatine crests 065 
 
 " of postglenoid process 095 
 
 " between postglenoid processes 095 
 
 " basioccipital at front 073 
 
 " " " condyles 200 
 
 " of space for lymphanic chamber 034 
 
 Length tusk on curve (12.7 inches) 320 
 
 Diameter at middle (antero-posterior) 050 
 
 " " base " " 063 
 
 " " middle (transverse) 030 
 
 11 " crown P. M. 1 transverse 022 
 
 " " antero-posterior 024 
 
 " " M. 1 " " 035 
 
 " " " transverse 034 
 
 M. 2 " 043 
 
 11 antero-posterior 045 
 
 Elevation of shovel above base of apex of nasal .060 
 
 The measurements may require some correction in respect to the 
 supraorbital width, where the cranial walls have suffered from compres- 
 sion. The frontal of one side has been pushed so as to overlap that of 
 the other by about an inch. 
 
 The scapula is of a sub-triangular form, the front being vertical, the 
 apex directed backwards and an angle upwards. The posterior expansion 
 is considerable, as in the elephants, while the superior angle is acumin- 
 ate and much produced and massive. The spine is much elevated, 
 bounding a deep supraspinous fossa. It is truncate in front descending 
 to near the border of the glenoid cavity. Its extremity is dilated in 
 alate fashion, equally fore and aft, and not posteriorly only as in the 
 elephants. The glenoid cavity is flattened so as to be longitudinal, and 
 the coracoid is a rudi mental tuberosity. 
 
 Measurements of Scapula. 
 
 JM-. 
 
 Total length (25.25 inches) 0.640 
 
 " width 480 
 
 Length apex from spine 140 
 
 Elevation of spine proximally 125 
 
 Length of glenoid cavity 185 
 
 Width " " " 110 
 
 The interior side of the scapula is strongly convex by the development 
 
13 
 
 of two longitudinal ribs, one corresponding to each fossa, but concave in 
 longitudinal section. 
 
 The proximal end of the radius exhibits two facets oblique to each 
 other, the larger concave and transverse, the other oblique downwards. 
 Transverse width M. 0.130 ; vertical .070. The extremity of a humerus 
 not found with this individual, to which the radius applies pretty well, 
 has a very oblique trochlear face, and measures seven inches across the 
 condyles. It, however, belongs to a smaller species. 
 
 The femur is entire. Like that of other species of the group it is 
 much expanded proximally and deep distally, with the shaft contracted 
 and somewhat flattened in the plane of the great trochanter. The latter 
 is in one plane, with its external margin turned a little backwards. The 
 head is part of a globe, and is a little more elevated than the trochanter, 
 and separated from its apex by a shallow concavity. There is no little 
 trochanter. The trochlear face is not elevated nor wide, and with lateral 
 borders subequally developed. The aiitero-posterior axis of the con- 
 dyles is somewhat oblique to a line at right angles to the proximal end. 
 On this account the interior coaidyle is the longer ; its articular face is 
 continuous with the trochlear, with a marginal notch ; the outer condyle 
 is continuous, with continuous outer margin. Strong ridges revolve 
 from above the condyles to the posterior face of the shaft, the inner near 
 the condyle. The outer runs parallel to the main axis as a low external 
 ala, and backwards three inches above the condyle. The face between 
 them is concave. 
 
 Measurements of Femur. 
 
 M. 
 
 Total length, (31.75 in.) ' 0.747 
 
 Total proximal width 255 
 
 Diameter of ball 136 
 
 Transverse diameter at middle of shaft 096 
 
 Antero-posterior " " " 074 
 
 " condyles posteriorly 150 
 
 Transverse " " " 160 
 
 " " " distally 145 
 
 The pelvis has a large transverse expansion. The iliac plates are ovoid 
 in outline, with the apex outwards and downwards. The margins are 
 rather thin excepting the internal above the acetabulum. These are 
 massive, and with a longitudinal excavation. They terminate in a deep 
 oblique excavation for the diapophyses of the sacrum. The external 
 margin rises compressed from just above the acetabulum. The latter is 
 large for the size of the ilia, and its margins rise to a slight elevation be- 
 neath the exterior margins of the latter. The incisura acetabuli is ob- 
 clavate, and nearly symmetrical. The os ischium is compressed and deeper 
 than the pubis. It possesses a tuberosity on the posterior inferior mar- 
 gin. The obturator foramen is small and is a vertical oval. The pubis is 
 rather slender and short. ' Its section at base is subtriangular; beyond, 
 
14 
 
 it becomes more compressed, and is spirally twisted on itself through 
 part of a circle. Its anterior margin near the symphysis is strongly 
 rugose for the origin of the pectineus muscle; the rugosity extends into a 
 band on the outside of its proximal portion. 
 
 Measurements of Pelvis. 
 
 M. 
 
 Long diamater of ilium 0.605 
 
 Transverse do. at acetabulum 430 
 
 Length inferior free margin do 250 
 
 Long diameter acetabulum 150 
 
 Shorter " " 130 
 
 " " obturator foramen 070 
 
 Width ischium at tuberosity 140 
 
 Length " to " 110 
 
 Diameter pubis at obturator foramen 062 
 
 Expanse of ilia laid on a flat surface and with sacrum 
 
 fn place (4.2 ft.) 1.280 
 
 The general character of the pelvis is more like that of the Elephant 
 than that of any Perissodactyle. It agrees with the former and differs 
 from that of the Ehinocerus in the shortness of the pedestals of the ilia 
 or rather in the sessile position of the latter on the acetabula; also in the 
 absence of production of the iliac crests in advance of and above the 
 sacrum. It is also elephantine in the shortness of the inferior elements 
 of the pelvis. 
 
 Of vertebra, there are preserved a dorsal, two lumbar, and some sacral. 
 The first is very short and transverse. It is so injured that I can only 
 give measurements. The base of the transverse neurapophysis is a flat 
 oval; both capitular articular surfaces are deep. The anterior lumbar 
 is longer, but still short; its articular faces are slightly concave. The 
 neural arch is wide, and supports the diapophysis. The sides of the 
 centrum are concave and pierced by foramina, and there is p, strong 
 rugose hypapophysis. The section at the middle is subtriangular. I 
 have three sacral vertebra which are separated by very distinct sutures. 
 They diminish very rapidly in size, and the centra become flattened trans- 
 verse. It is doubtful whether there was a fourth vertebra, and the tail 
 must have been short and slender. The articular face of the first is 
 a transverse rather broad ellipse and twice the diameter of the third 
 distally. The diapophysis of the second is much the stoutest. It unites 
 with the subvertical plate-like diapophysis of the first as well as with 
 that of the third. It is concave above, and terminates distally in a mas- 
 sive L-shaped surface of articulation with the ilium. The foramina en- 
 closed by the diapophyses are quite large. The inferior face of the first 
 sacral centrum is slightly concave with a hypapophysial tuberosity in 
 front; it is strongly concave in the second. 
 
15 
 
 Measurements of Vertebra. 
 
 M. 
 
 Antero-posterior diameter of dorsal 0.044 
 
 Diameter at bottom neural arch do 040 
 
 Length base of neurapophysis 041 
 
 Diameter centrum lumbar (vertical) 090 
 
 " " " (transverse) 110 
 
 " " " (antero-posterior) 080 
 
 Length three sacral vertebrae 226 
 
 Transverse extent of sacrum (15 in.) 380 
 
 Diameterfirst vertebra at free end (transverse) (4.6 in.) .122 
 
 " " " " Vertical) 093 
 
 < last " " " 021 
 
 " " " " (transverse) 065 
 
 Total expanse of heads of rib 106 
 
 Diameter capitular face (vertical) 048 
 
 " tubercular " 030 
 
 Width rib just below head .050 
 
 Restoration. We may ascribe to the Loxolophodon cornutus, form and 
 proportions of body similar to those of the elephant. The limbs, however, 
 were somewhat shorter, as the femur is stouter for its length than in the 
 E. indicus. It was intermediate in this respect between the latter species 
 and the species of Ehinocerus. The tail was quite small. The neck was 
 a little longer than in the elephants, but much less than in the rhinoce- 
 roses; the occipital crest gave attachments to the ligamentum mucJtce and 
 muscles of the neck, which must needs have been powerful to support 
 the long muzzle with its osseous prominences, and to handle with effect 
 the terrible laniary tusks. The head must have been supported some- 
 what obliquely downwards, presenting the horns somewhat forwards as 
 well as upwards. The third or posterior pair of horns towered above the 
 middle ones, extending vertically with a divergence, when the head 
 was at rest. The posterior and middle pair of horns were no doubt 
 covered by integument in some shape, but whether dermal or corneous 
 is uncertain. Their penetrating foramina are smaller than in the Bovidce. 
 The cores have somewhat the form of those of the Antilocapra americana, 
 whence I suspect that the horns had an inner process, or were palmate 
 as in the prong-horn at present inhabiting the same region. The nasal 
 shovels may have supported a pair of flat divergent dermal horns, but 
 this is uncertain; they are not very rugose. 
 
 The elevation of the animal at the rump was about six feet, distributed 
 as follows: 
 
 Inches. 
 
 Foot 4.50 
 
 Tibia '. . . 20.50 
 
 Femur : 31.75 
 
 Pelvis 16. 
 
 72.75 
 
16 
 
 The anterior limb was stouter than the posterior, judging from the 
 proportions in Eobasileus pressicornis, and were no doubt more elevated, 
 if of the Proboscidian character. This would give us the hypothetical 
 
 elevation at the withers : 
 
 Inches. 
 
 Leg 61.00 
 
 Scapula (actual) 21.00 
 
 Neural spines (extremities) 7.00 
 
 Or seven feet, five inches 89.00 
 
 These measurements are made from the plantar and palmar surfaces, 
 allowance being made for the pads. 
 
 The neck, estimating from tne dorsal vertebrae and from the cervicals 
 of other species preserved, could not have exceeded one foot in length, and 
 may hava been less. This added to the length of the cranium, gives a 
 total of about four feet. The obliquity of the antero-posterior axis of 
 the cervical vertebrae, indicates that the head was posteriorly elevated 
 above the axis of the dorsal vertebrae. Thus it is entirely clear, that the 
 muzzle of this animal could not have reached the ground by several feet, 
 and that, as occurs in the similar cases of the Tapirs and Elephants tkere 
 was a proboscis to supply that necessity. The indications derived from 
 the bones of the muzzle confirm this conclusion, as has been already 
 pointed out. There could have been no interference from the horns near 
 the ends of the nasal bones, for the bases of these project beyond the 
 origin of a proboscis, and were directed outwards while the latter hung 
 downwards. 
 
 This species was probably quite as large as the Indian Elephant, for 
 the individual described is not adult, as indicated by the freedom of the 
 epiphyses of the lumbar vertebrae, and fragments of others in my posses- 
 sion indicate considerably larger size. 
 
 Habits. The very weak dentition indicates soft food, no doubt of a 
 vegetable character, of what particular kind it is not easy to divine. The 
 long canines were no doubt for defense chiefly, and may have been use- 
 ful in pulling and cutting vines and branches of 'the forest. The horns 
 furnished formidable weapons of defense . That the anterior nasal pair 
 were not used for rooting in the earth is evident from the elevation of the 
 head, which would render this impossible. 
 
 This huge animal must have been of defective vision, *for the orbits 
 have no distinctive outline, and the eyes were so overhung by the horns 
 and cranial walls as to have been able to see but little upwards. The 
 muzzle and cranial crests have obstructed the view both forwards and 
 backwards, so that this beast probably resembled the Rhinoceros in the 
 ease with which it might have been avoided when in pursuit. 
 
 Locality. The remains of the Loxolophodon cornutus were found by the 
 writer in August, 1872, in a ravine of the bad lands of Wyoming. The 
 greater part of the cranium and the femur were excavated from the base 
 of a cliff of perhaps 250 feet in height, on the side of a ravine elevated 
 
17 
 
 about 1000 feet, in the Mammoth Buttes, on South Bitter Creek. As 
 the basin of Bitter Creek is 7,500 feet above the sea, the fossil was taken 
 from an elevation of 8,500 feet. The horizon is the Bridger Group of 
 the Eocene of Hayden. 
 
 EOBASILEUS. Cope. 
 
 Proceedings of the American Philosophical Society, 1872, p. 485 (Au- 
 gust 20th). 
 
 As pointed out above, this genus resembles Loxolophodon in the very 
 short cervical vertebrae, but agrees with Uintatherium in the rudimental 
 condition of the nasal horn-cores, which are mere tubercles. The posterior 
 or third pair of horn-cores are also very different, and probably stand on 
 the largely developed lateral crests of the superior surface of the cranium, 
 as in Uintatherium. They are apparently preserved in E. furcatum 
 (which is not the type of the genus), and are compressed from base to 
 summit ; in Loxolophodon the base is nearly cylindric. 
 
 The characters of this genus had not been indicated 'in any of the de- 
 scriptions published by palaeontologists prior to its establishment as above 
 cited. It is possible that Tinoceras grandis of Marsh may be synony- 
 mous with one of the species here referred to it, but this point cannot be 
 determined from the descriptions of that author. 
 
 The cervical vertebra in E. pressicornis are very short. The limbs are 
 much as in Loxolophodon, as are the scapula and pelvis. The symphysi& 
 pubis of E. pressicornis, or an ally, is short, and was separated from the 
 ischiadic symphysis, but whether this belongs to the genus is not entirely 
 certain. 
 
 The namcular bone, of perhaps the same species as the above, displays, 
 as in living proboscidians, four inferior facets, thus proving the existence 
 of five toes to the hind foot. The external facet is deeply concave, and 
 contains a pit. It is oblique, and unites with the superior face by an 
 acute angle. It supported the small inner toe by its metatarsus directly. 
 The other three are more nearly on one plane, and are deeper than wide. 
 The navicular is in form a little less than a quarter of a circle, and the 
 external (anterior) depth is one half its transverse length. Its superior 
 surface is slightly convex. 
 
 EOBASILEUS PRESSICOKNIS. Cope. 
 
 Loxolophodan pressicornis, Cope. Proceed. Amer. Philos. Soc., 1872, 
 p. 580 (published August 19th). Loc. cit., p. 488 (August, 22). Eobasil- 
 eus cornutus, Cope, 1. c., p. 485 (Aug. 20th), not Loxolophodon cornutus, 
 Cope, 1. c., Aug. 19. 
 
 Represented by numerous portions of the cranium, with fragments of 
 limbs of one individual ; of almost all portions of the skeleton except the 
 cranium, of a second. A humerus with astragalus of a third are of un- 
 certain reference, while a single humerus of another species may belong 
 here. Fragments of several other individuals of appropriate size may 
 pertain to it. 
 
18 
 
 The cranium is represented by nasal, maxillary, malar, occipital bones, 
 etc. The first named has a half conic apex, and an oblique compressed 
 tuberosity, which forms the lateral border behind it, and is directed ob- 
 liquely upwards. The apex of each nasal is vertically compressed acute, 
 and is deeply pitted and rugose for muscular or ligamentous attachments. 
 The inferior lateral marginal ridge is contracted, and encloses a concave 
 median space. The tuberosity sinks to the level of the median suture. 
 The posterior part of the nasal rises to the apex of the middle horn-core, 
 forming its inner face. The postero-superior angle of the premaxillary 
 reaches to near the base of the horn, and is not drawn out to a narrow 
 apex as in L. cornutus. The horn is compressed antero-posteriorly at 
 the base; at the apex obliquely inwards and forwards. The outer face is 
 concave on the lower half, the inner convex. The posterior face is con- 
 cave and the anterior convex when viewed from the side. 
 
 Measurements of Nasal Bone. 
 
 M. 
 
 Width of both at tuberosity 0.124 
 
 11 base of distal cone 060 
 
 Depth of suture at front of tuberosity 030 
 
 Length of suture from premaxillary to horn-core 035 
 
 " horn-core (in front) (6 in.) 150 
 
 Diameter (externally) 080 
 
 11 of apex 048 
 
 TJie occipital region is furnished with an enormous transverse crest 
 which extends upwards and backwards. Its margin is gently convex, 
 and its supero-anterior face concave. The posterior is narrowed by the in- 
 ferior crest-Uke margins of the temporal fossa which extend from the squa- 
 mosal part of the zygoma and gradually contract, terminating abruptly 
 in a low knob where it joins the transverse crest. The posterior face 
 between the former is divided into two planes by a low vertical ridge, 
 which terminates some distance below the summit. The- transverse crest 
 is continued in a curve forwards on each side as the superior margin of 
 the temporal fossa. The specimen does not indicate whether these sup- 
 ported horns, but they are very stout. 
 
 Measurements of Occiput. 
 
 * M. 
 
 Elevation from, foramen magnum 0.180 
 
 Width between inferior temporal crests 250 
 
 " of condyles with foramen 180 
 
 Elevation above internal sinuses at angles 180 
 
 The mastoid tuberosity is short and stout ; the mastoid foramen is large 
 and not piercing a crest. The ex-occipital suture is obliterated. The A- 
 shaped crest behind the meatus in Loxolophodon cornutus is little marked 
 here. The surface of the bone has various muscular impressions. The 
 basi-occipital exhibits a low median crest dividing lateral concavities ; 
 
19 
 
 transverse width at condyles .077 M. The fragments of teeth are too 
 uncharacteristic for specific description. Numerous cranial fragments 
 accompany the above, but have not yet been properly placed. 
 
 The atlas is broken ; its cotyloid cavities are rather shallow, and the 
 diapophyses small. Its antero-posterior diameter below at the middle 
 line is .070 ; at base of diapophysis ".070. The condyles of the femur 
 present the characters of the group. There is a deep vertical groove on 
 the inner side just above the condyle. The latter approach each other 
 closely on each side of the intercondylar fossa and are flattened on the 
 superior posterior margins. Width across extremities M. .150. 
 
 At a distance of one or two hundred feet from the above specimen I 
 found portions of the skeleton of a smaller animal, probably a different 
 but allied species. It is represented by portions of ribs and limbs, of which 
 the ulna is described under Uintatherium. Two or three hundred yards 
 from the typical specimen, I obtained remains of almost all parts of the 
 skeleton of what is probably the present species. The femur is identical 
 in character. The specimen embraces cervical dorsal and lumbar verte- 
 brae, ulna, both femora and tibiae, astralagus, navicular, etc., and large 
 parts of the scapulae and pelvis. 
 
 The scapula in its proximal portions, differs little from that of Loxo- 
 lophodon cornutus besides in inferior size. The coracoid is a compressed 
 tubercle enclosing a groove with the glenoid cavity. 
 
 M. 
 
 Diameter glenoid cavity (longitudinal) 0.168 
 
 " " " (transverse) 098 
 
 The os pubis displays a strong pectineal rugosity commencing near the 
 acetabulum. 
 
 M. 
 
 Long Diameter of acetabulum 0. 143 
 
 Length ischio pubic suture 108 
 
 Diameter pubis near acetabulum 052 
 
 The femur is nearly as long as that of Loxolophodon cornutus, but is 
 more slender, and has a relatively smaller head. It is flattened fore and 
 aft, and the great trochanter is much expanded and with a shallow con- 
 cavity on the posterior face. There is a marked concavity on the posterior 
 face of the shaft above the condyles. There is a rudiment of the little tro- 
 chanter. The tibia is scarcely three-fourths the length of the femur, and 
 has a rather contracted shaft, which is in section rounded triangular, one 
 angle presenting forwards. There is no spine except a rudiment in the 
 swollen upper portion of the anterior ridge. The articular surfaces are 
 together rather narrowly transverse. They are separated by a keel which 
 is undivided posteriorly ; anteriorly the contiguous margins of the cotyli 
 separate. The long axis of the inner of these is directed antero-posteri- 
 orly outwards in front ; of the other similar but much more transverse. 
 It overhangs the shaft outwards and backwards and supports beneath, 
 the subround down-looking fibular articular surface. The distal articu- 
 
20 
 
 lar surface is distinguished from allied species by the downward promi- 
 nence of the malleolar process, the antero-posterior width, and the greater 
 extent of the fibular articular face. The face is slightly concave antero- 
 posteriorly and openly sigmoidal transversely. 
 
 Measurements of Leg. 
 
 JM. 
 
 Length with astragalus in place 1.200 
 
 Femur, length 750 
 
 " diameter ball 118 
 
 " width at great trochanter 220 
 
 " " " middle shaft 091 
 
 " depth " " 060 
 
 Tibia, length .470 
 
 u width proximal surfaces (transverse) 147 
 
 " " " (antero-posterior) 070 
 
 " transverse diameter shaft 061 
 
 " antero-posterior " 065 
 
 " " distal articulation 092 
 
 " transverse " " " 121 
 
 Fibula, length . % 430 
 
 ** transverse width at middle 032 
 
 " width proximal articular face 042 
 
 " " malleolar " " (transverse) 052 
 
 " " " " " (longitudinal) 044 
 
 A section of the fibula, near the proximal end, is sub-triangular ; a 
 short distance below, sub-circular; on the distal two-thirds it is flat, with 
 the thinner edge convex inwards. 
 
 The astragalus is a flat bone, with its entire superior face occupied by 
 the tibial articular surface. This is as broad as long, and very little 
 convex. It is broader in front than behind ; the outer margin is concave, 
 the inner slightly convex. The posterior margin projects most on the 
 outer side, and it is divided by a pit-like cavity, which sends a groove to 
 the inner margin. The outer malleolar surface is an antero-posterior 
 oval ; the inner, a concavity, beyond which the inferior portion of the 
 bone projects. The inferior face is divided by a prominent transverse 
 angle, between sub-anterior and sub-posterior faces. The latter receives 
 the calcaneum on two oval surfaces, which are joined behind by a narrow 
 strip. The navicular face is sub-rhomboid, the cuboid one-third as large, 
 and triangular, with a round base outwards. The margin of the former 
 scarcely projects beyond the superior face. 
 
 Measurements of Astragalus. 
 
 M. 
 
 Total width 0.128 
 
 " length 107 
 
 Width tibial face in front. . .090 
 
21 
 
 M. 
 
 Length tibial face externally 088 
 
 " internal malleolar face 045 
 
 " outer calcaneal do. antero-pesteriorly 050 
 
 Length navicular facet 095 
 
 Width do. (antero-posterior) 060 
 
 Length cuboid facet 065 
 
 Width do. (antero-posterior) 035 
 
 A navicular belonging to the individual mentioned first has been already 
 described. 
 
 Measurements of Navicular. 
 
 M. 
 
 Depth in front 048 
 
 Width (transverse) 097 
 
 " of external facet.. 035 
 
 " " second 026 
 
 " third 047 
 
 " " internal 023 
 
 A distal end of a humerus was found with two astragali about a hun- 
 dred yards from the last individual. The articular face is very oblique 
 to the transverse axis, but is about equally developed on opposite sides of 
 the shaft. The condyles are unequal, have parallel axes, and are separated 
 by but a shallow concavity. The fossae of opposite sides are not very 
 large nor deep. 
 
 Measurements of Humerus. 
 
 M. 
 
 Transverse diameter distally 175 
 
 Do. of inner condyle 104 
 
 " outer " 125 
 
 Transverse diameter olecranon 110 
 
 The portion of ulna just measured belongs to the individual of which 
 so many fragments were found, or No. 2. 
 
 The dorsal vertebrae of the same are somewhat distorted by pressure ; 
 I will therefore describe a cervical of natural form. The centrum is very 
 short, and the articular face is a wide, transverse oval. Both are slightly 
 concave, and the axis being slightly oblique, the anterior is the more 
 elevated. The surface of the latter is quite rugose, except on the margins. 
 The cervical canal is wide, and the neur- and parapophyses narrow. In- 
 ferior surface regularly convex. 
 
 Measurements of Cervical Vertebra. 
 
 M. 
 
 Length centrum 044 
 
 " basis neurapophysis 040 
 
 " anterior articular face 102 
 
 Depth " " 086 
 
 Width neural canal at base ... .060 
 
22 
 
 Restoration. The elevation of this animal was not much less than that 
 of the LoxolopJiodon cornutus, but the proportions were more slender. As 
 in all the species of Uintatherium in which the horns are known, these 
 appendages stood in front of the orbits, and nearer the nareal opening 
 than in the type of the former genus. The muzzle, too, is materially 
 shorter and more contracted, and the true apex of the muzzle was not over- 
 hung by the great cornices seen in Loxolopliodon. The horn-sheaths were 
 probably simple, while in L. cornutus they were probably palmate. The 
 occipital and parietal crests are much more extended in this species than 
 in the L. cornutu% so that in life the snout and muzzle had not such a 
 preponderance of proportion as in that species. All the species of this 
 genus were rather more rhinocarotic in the proportions of the head, 
 although the horns and tusks produced a very different physiognomy. 
 The extremities of the nasal bones, though not excavated as in that 
 species, are strongly pitted and exostosed, and this taken in connection 
 with the elevation of the head renders it probable that this species also 
 possessed a proboscis. 
 
 History. This species was originally described by the writer in a short 
 paper, which was published and distributed August 19th, 1872, under the 
 generic name Loxolophodon. I shortly afterwards referred it to the new 
 genus Eobasileus, under the name cornutus, under the impression that it 
 was the same as the Loxolophodon cornutus; but finding this was not the 
 case, I again used the specific name here adopted. More than a month 
 later Prof. Marsh (September 21st) described a species under the name 
 of Tinoceras grandis, which agrees with this one so far as relates to the 
 length of horn-cores, but that it is the same species cannot now be 
 positively asserted. I originally (August 20th, 1872) alluded to the 
 horn-cores as situated on the frontal bones ; Marsh has since asserted 
 them to be composed of the maxillaries. I have discovered on the first 
 opportunity of making a detailed examination, that the inner face is 
 composed of the posterior part of the nasal bones, and the exterior of 
 the maxillaries. 
 
 EOBASILEUS FUBCATUS. Cope. 
 
 Loxolophodon bifurcatus, Cope, in extra copies on Proboscidians of the 
 Eocene of Wyoming, August 19th 1872.* Loxolophodon furcatus in the 
 same, Proceedings American Philosophical Society, 1872, p. 580, Aug- 
 20th. L. c. 488, August 22d. 
 
 This species was originally described from a large horn-core whose 
 extremital part resembles strongly the nasal shovel of Eobasileus cor- 
 nutus, on which account I referred it to that position on the skull. 
 Marsh has described somewhat similar horn-cores from the lateral crests 
 of the skull behind in II. mirabile, whence it may be that my specimen is 
 referable to that position, although it differs much from those of that 
 species. 
 
 * See Proceedings American Philosophical Society, 1872, p. 515, where this name is recorded. 
 
23 
 
 The basis is very narrow and lenticular ; a short distance above it the 
 outer side is convex. The anterior and posterior extensions of the base 
 differ ; the one is thinner, the other more massive and with a shallow 
 groove above its commencement. The latter may be posterior. If so, 
 the compressed apex of the horn-core sends down a rib outwardly to the 
 anteriorly and one inwardly, which disappears on the convex base. The 
 general form is spatulate with the apex expanded obliquely across the lat- 
 eral crest, and regularly rounded in superior outline. Its anterior face 
 is flat, the posterior convex ; its surface is grooved by very small blood 
 vessels. 
 
 As compared with the posterior horn-core of Loxolophodon cornutus, 
 there is every difference. That is continuous with one margin of the 
 crest ; this, erect above it ; that has a round base, this a lenticular one. 
 It is more like that of U. mirabile, which I only know from Marsh's figure, 
 but abundantly distinct. It is much more elongate, especially above the 
 posterior ? part of the crest, and is flattened, and without the triangular 
 section of that species. 
 
 Measurements of Horn-core. 
 
 M. 
 
 The total length above crest (5.5 inches) 0. 135 
 
 " " " " base (7^ inches) 180 
 
 Width across apex (in front) * 095 
 
 Thickness across apex (in front) 028 
 
 "' at base 040 
 
 It is not certain that this horn may not belong to the E. pressicornis, if 
 it be a posterior core, of which, however, I am not yet entirely sure. In 
 that case the name furcatus, under which it was first described, becomes 
 a synonym of E. pressicornis. 
 
 UINTATHERIUM. Leidy. 
 
 Proceedings Academy Natural Science's, Philadelphia, 1872, page 169 
 (published early in August). Dinoceras, Marsh, Amer. Journ. Sci. Arts, 
 1872. October, 1872 (published September 27). 
 
 This genus resembles the last in its general proportions, but differs in 
 its more elongate cervical vertebrae. The centra of these are flat at both 
 extremities, but have not such a marked elephantine abbreviation as 
 seen in the two genera above described. This enabled the head to 
 approach the ground more nearly, and as the limbs were shorter in some 
 of the species, they no doubt modified the length of the proboscis, if 
 present. 
 
 Several names have been applied to this genus. Professor Leidy's 
 name here employed, bears date early in August, but of the precise day 
 I am not informed. Professor Marsh, in the Am. Jour. Sci. and Arts, 
 1872 (Sept. 21st), applied the name Tinoceras toj a species (T. grandis] 
 perhaps of this genus, and gave a description in which some of the 
 
24 
 
 generic characters may have been mentioned. He had previously applied 
 it without description to the Uintatherium anceps, Aug. 24th (and 19th*, 
 in an erratum, where Mastodon anceps is altered into Tinoceras anceps}. 
 As no characters whatever were assigned to it on either of these occa- 
 sions, it had no value in zoological nomenclature, and must bear date 
 September 21st. Under date of September 27th, Prof. Marsh proposed 
 the name Dinoceras (American Journal Science Arts, 1872) for the V. 
 mirabile, but did not give his reasons for separating it from his former 
 genus (the names of the two bear an objectionable resemblance), or 
 those published by Dr. Leidy, or myself. Until such reasons be adduced, 
 I retain it also in Uintatherium, as is done by Dr. Leidy. 
 
 I am acquainted, by autopsy, with two species of this genus. None of 
 them are so large as the Eobasileus pressicornis ; U. robustum, Leidy, 
 is smaller, and the U. lacustre, Marsh, smaller still. U. mirabile 
 (Dinoceras, Marsh) is about the size of the U. robustum, and nearly allied 
 to it ; but it may be distinct, as it has a larger mastoid process. Tinocera* 
 grandis, Marsh, agrees in measurements with the E. pressicornis, and is 
 perhaps that species or the E. furcatus. The Tinoceras anceps, Marsh, 
 has been so imperfectly characterized as to be practically unknown. It 
 is one of the smaller species, and is most likely to be identical with the 
 IT. robustum, whose name it antedates. Until these points be cleared up, 
 I retain three species, as follows : Uintatherium robustum, Leidy ; U. 
 mirabile, Marsh ; U. lacustre, Marsh. For convenience I compare these 
 species with those of Eobasileus. 
 
 The naso-maxillary horn-cores have been seen in E. pressicornis and U. 
 mirabile, and the nasal tubercles in the same. The posterior horn-cores 
 are known in the U. mirabile. The posterior and lateral crests of the 
 cranium inclose a basin-shaped concavity above in all these species ; it 
 has been observed in all but E. furcatus. The dentition is similar to 
 that in Loxolophodon,, i.e., I. ; C. 1 ; P. M. 4 ; M. 2. The first premolar 
 in U. lacustre has an internal cone and outer concave crest. The 
 worn surfaces of the other teeth in that species, U. robustum and 
 U. mirabile, are narrow ovate, with a deep exterior emargination. The 
 true molars support two crests, which converge inwards and unite with 
 a small tubercle behind the apex in U. lacustre and U. robustum. The 
 tusk is long, compressed and double-edged, as in Loxolophodon. , The 
 last inferior molar in U. robustum possesses three transverse crests, the 
 posterior two parallel, and obliquely directed inwards towards the axis 
 of the anterior, which is the highest. 
 
 In a specimen of one of the smaller species, the ulna widens consider- 
 ably distally, being nearly as wide as the olecranon. The latter is large, 
 flattened and subtransverse, and presents a sharp ridge internally. On 
 the inner side of the distal part of the articular face for the humerus is a 
 tubercle, from which a short, wide groove runs out on the inner face of 
 
 * These papers were riot recaived by me till early iu December, 1872. 
 
25 
 
 the bone, the head of the radius is a little exterior to the middle line, and 
 the shaft crosses the ulna in an open, shallow groove to the inner side. 
 
 The cuboid is flat, and displays two proximal and two distal articular 
 facets in P . fftrcatum. The astragalus of the same species is subbifurcate 
 posteriorly, and has internally an extensive, oblique malleolar fossa. The 
 calcaneum is short and massive, with two superior and one small anterior 
 articular facet. 
 
 The species may be thus distinguished : 
 
 1. Large species (occipital condyles extending over about M. 0.170.) 
 Naso-maxillary horns long ; tibia with wide articular 
 
 faces E. pressicornis. 
 
 Horn-cores flat, elevated E. furcatus. 
 
 2. Species of intermediate size. 
 
 A prominent mastoid process, molars smaller V. robustum. 
 
 Mastoid process not prominent; maxillary horn-cores low, 
 triangular; posterior horn-cores short, triangular in section II. mirabiU. 
 8. Smallest species (occipital condyles extending over about M. .95.) 
 Molar teeth larger, the last with a posterior expansion. . IT. lacustre. 
 Previous to describing the species I notice a part of the skeleton of a 
 large mammal, second only in bulk to Loxolophodon and Eobasileus above 
 described. 
 
 These, which were not found in association with a cranium, consist 
 of several vertebrae, some carpal bones, the entire hind limb of the left 
 side except the toes and the cuneiform and navicular bones. 
 
 The odontoid process is very stout, with a descending trihedral apex. 
 Length M. .078, diameter at base, .048. A dorsal vertebra with a single 
 (anterior) capitular articular face, is quite concave in front. 
 
 M. 
 
 Diameter antero-posteriorly 057 
 
 " vertically 094 
 
 A cervical vertebra has the proportions of the dorsal as to its centrum, 
 thus differing materially from species previously described. The articu- 
 lar surfaces are slightly concave. 
 
 jM. 
 
 Length (antero-posteriorly) 0.065 
 
 Diameter vertical 087 
 
 ' ' transverse 100 
 
 The femur resembles that of the other species already described, but 
 is remarkable for the relatively small size of the head. While the lengths 
 of the bone are not very different, and the expanse of the great trochaiiter 
 about the same, the head of L. cornutus is large, the present one is 
 very much smaller, and that of E. pressicornis intermediate. There is a 
 rudimental third trockanter, and the condyles are as large as, and similar 
 to those of, E. pressicornis. The external marginal condylar ridge is 
 quite short. The shaft is broken and some small pieces lost ; it is now 26 
 inches long, but was no doubt longer when complete. 
 
26 
 
 Measurements of Femur. 
 
 M. 
 
 Expanse of great trochanter 0.230 
 
 Diameter of head * . -109 
 
 " " shaft at middle 093 
 
 " above condyles 152 
 
 " at extremity of condyles 139 
 
 11 (vertical) of inner condyle 125 
 
 The tibia is perfectly preserved. It is short and stout and with massive 
 extremities. The outer basal part of the spine remains and is prominent. 
 The cotyli are not oblique ; the inner is subround, the outer transverse, 
 widening outwardly ; their long axes are at right angles to each other. The 
 crest is a low ridge of contact of the cotyli. The superior fibular face is 
 a transverse oval ; the inferior much smaller than in E. pressicornis. The 
 shaft is contracted, and flattened behind and on the inner side. The dis- 
 tal extremity is transverse, less truncated for the fibula than in E. pressi- 
 cornis, less convex behind, and with a less prominent external malleolus- 
 The point dividing the astragalus behind is more prominent. 
 
 Measurements of Tibia. 
 
 M. 
 
 Total length 0.398 
 
 Diameter head .longitudinal 080 
 
 " " transverse 138 
 
 " shaft transverse 063 
 
 " " antero-posterior 060 
 
 " distal articulation " 077 
 
 " " " transverse 113 
 
 " " extremity, fore and aft 093 
 
 " " " transverse , ,125 
 
 These measurements show that this bone is considerably shorter than 
 in E. pressicornis, though of equal distal diameters. In both species the 
 measurements considerably exceed those given by Marsh for his Titano- 
 therium (?) anceps. The form of the articular extremities differs from 
 both in being more narrowed and transverse. 
 
 The fibula is larger proximally and smaller distally than in E. pressi- 
 cornis. Diameter proximal articular face .039 ; of the distal .045. 
 
 The astragalus is similar in size and form to that of E. pressicornis, but 
 differs in two points. The posterior margin is deeply incised for the lig- 
 amentous insertion, and the outer lobe is clearly cut to this fossa, on the 
 inner side. There is a pit for a ligament on the convexity of the inner 
 part of the middle of the tibial articular face. A third difference is seen 
 on the inferior face. The inner calcaneal facet is longer and narrower, 
 and is margined on the inner side by a large fossa parallel to its axis, 
 which is wanting in the other species. The calcaneum is short and wide ; 
 
27 
 
 its only anterior articulation is with the cuboid and is small. The heel is 
 deeper than long and is obliquely truncate downwards and inwards. 
 
 Measurements of Calcaneum. 
 
 M. 
 
 Length r. 0.105 
 
 Width . .092 
 
 Depth in front 056 
 
 Length heel 047 
 
 Depth " 055 
 
 Length cuboid facet 038 
 
 The cuboid is a flat sub-triangular bone with two unequal articular 
 faces below. 
 
 M. 
 
 Length 064 
 
 Width 076 
 
 Depth 031 
 
 Length cuneiform (antero-posterior) 040 
 
 Depth " 017 
 
 A humerus of a third specimen may or may not belong to this species. 
 It was found in another locality. Its condyles are much less oblique than 
 in that one described under E. pressicornis. It belonged to a larger 
 animal, see 
 
 Measurements of Humerus. 
 
 M. 
 
 Transverse diameter distally (7.75 in.) 195 
 
 " " inner condyle 125 ' 
 
 The olecranar fossa is shallower. 
 
 Remarks. The remains were discovered by the writer in the Bridger 
 Bad Lands on South Fork of Bitter Creek, Wyoming. 
 
 UlNTATHERIUM ROBTJSTUM. Leidy. 
 
 Proceedings Academy Natural Sciences, Philadelphia, 1872, p. 169, 
 August. Uintamastix atrox, Leidy, 1. c. (? ?) Titanotherium anceps, Marsh, 
 American Journ. Sci. Arts, 1871, p. 35. 
 
 I have been able to examine, through the kindness of Prof. Leidy, the 
 type of his description, and find it to belong to a smaller species than any 
 of those above described. The lateral parietal and supra-occipital crests 
 are well developed, and the latter extends obliquely backwards. Several 
 peculiarities are to be observed in the dentition. Thus there is great in- 
 equality in the height of the transverse crests of the posterior upper 
 molar, the anterior, or the arched one, rising to a high cusp at its outer 
 extremity. A small tubercle exists on the side of the inner angle of the 
 grinding surface in the penultimate molar. The same angle is much 
 elevated in an anterior molar. The canine is wider distally than in Z. 
 
28 
 
 cornutus, and less recurved. The mastoid process is quite prominent. 
 The humerus has a prominent internal condyloid ridge and tuberosity, 
 and the condyles are not very oblique. The inner posterior lobe of the 
 tibial face of the astragalus is quite well denned ; there is no median 
 ligamentous pit on the trochlear face. 
 
 Measurements (from Leidy). 
 
 Inches. 
 
 Depth lower jaw at last molar 3.25 
 
 Length humerus about 21. 
 
 Diameter at condyles 7.50 
 
 Found by Dr. J. V. Carter and Dr. Leidy near Fort Bridger, Wyoming. 
 
 Dr. Leidy has suggested that this species and the Dinoceras mirabilis 
 of Marsh are identical. 
 
 UlNTATHERIUM MIRABILE. Marsh. 
 
 Dinoceras mirabilis, Marsh, Amer. Journ. Sci. Arts, 1872, October 
 (published Sept. 27). Loc. cit. Jan. 28th, 1873. 
 
 The cranium of this species has been very partially described as above 
 cited, but from figures in the last named paper, largely supply the de- 
 ficiency. From this it is evident that it differs from LoxolopJiodon cornutus 
 in the generic characters already mentioned, and, further, in the anterior 
 position of the naso-maxillary horns, the perforation of the lachrymal, the 
 anterior development of the malar, the oblique occiput, &c. It differs 
 from, the E. pressicornis, besides the inferior size, in the shorter nasal 
 bones and greater posterior approach of the pre-maxillary bones to the 
 base of the horns ; in the much shorter horns and greatly smaller part 
 taken in their composition by the nasals. 
 
 These differences account for the great number of errors committed by 
 Prof. Marsh in his allusions to other species, especially LoxolopJiodon 
 cornutus described by me (see his second article above quoted) . 
 
 Measurements. (From Marsh). 
 
 M. 
 
 Length of cranium (28.5 inches) 722 
 
 Width over orbits 202 
 
 " between summits naso-maxillary cores 169 
 
 " " " nasal " 038 
 
 Height naso-maxillary cores (3 inches) , 075 
 
 Length canine (9.25 inches) below jaw 232 
 
 Diameter fore and aft at base 064 
 
 " transverse " " 025 
 
 Length of molar series 150 
 
 Last superior do 036 
 
29 
 
 UlNTATHERIUM LACUSTRE. Marsh. 
 
 Dinoceras lacustris, Marsh, 1. c. October, 1872. (Published September 
 27th, 1872.) 
 
 I have several of the teeth and the occipital, parietal and other por- 
 tions of the cranium of this species. It is distinguished from its con- 
 geners, apart from its smaller size, by the large size of teeth. These are 
 nearly as large as those of Loxolophodon cornutus, and considerably larger 
 than those of U. robustum and U. mirabile. The occipital condyles are 
 not larger than those of the Elk, Cervus canadensis. The mastoid pro- 
 tuberance is prominent, and the post-glenoid process more produced 
 downwards and with less fore and aft diameter than in the other three 
 species. The inferior temporal ridge is strongly marked, and the pos- 
 terior condyloid foramen is large. 
 
 The posterior molar has a wide floor extending from the posterior or 
 straight transverse crest to the cingulum. This crest is low and has a 
 low tubercle near its apex behind. The other molars have strong fore 
 and aft cingula but none at ends. The worn surfaces are first V-shaped, 
 later arrow-shaped. The first premolar has curved outer crest and inner 
 conic tubercle. 
 
 Measurements. 
 
 M. 
 
 Diameter of occipital foramen and condyles 092 
 
 From exterior end condyle to mastoid 058 
 
 " " " " to post-glenoid process 080 
 
 Transverse diameter last upper molar 045 
 
 " " third premolar 029 
 
 Length molar series 163 
 
 Found by the writer in the Bridger formation of South Bitter Creek, 
 Wyoming. 
 
 MEGACERATOPS. Leidy. 
 
 Proceedings Academy Natural Sciences, 1870, p. 1. Hayden's Geo- 
 logical Survey, Wyoming, 1872, 352 ("Megacerops"). 
 
 This genus is only known from the extremity of the nasal bones bear- 
 ing the horn-cores. The latter are intermediate in position to the nasal 
 and naso-maxillary horns of Eobasileus, etc., and may represent the 
 median pair, in which case, the diagnosis of the genus should be, nasal 
 horn-cores wanting. 
 
 The genus was originally regarded by Dr. Leidy as allied to Sivatheriitm 
 and therefore Ruminant ; he also supposed that it possessed a proboscis 
 "as in the tapir." The latter proposition has much in its favor, especi- 
 ally as the affinities of the genus are evidently with the Proboscidia. 
 
 MEGACERATOPS COLORADOENSIS. Leidy. 
 Megacerops Coloradoensis. Leidy, i. c. 
 The part of this species preserved, indicates an animal of the size of 
 
30 
 
 the largest Uintatheria. The nasal bones are coossified, and the horn T 
 cores are sub-cylindric, obtuse and about two inches in length. They 
 are situated above a point a little behind the anterior nares. 
 
 PANTODONTA. 
 
 As already pointed out, the structure of the limbs and feet in this 
 suborder is as in the order generally, and the scapula has the same form 
 in general. There is also a resemblance in the form of the symphysis 
 mandibuli, which though furnished with teeth, forms a long solid spout 
 comparable to that of the^ Elephant. The astragalus has a very peculiar 
 form, being even more exceptional than in Uintatherium. The superior 
 articular surface is flat or concave in the middle. It is turned inwards 
 in front of the articular face fot the inner malleolus, terminating in a 
 long point. The cuboid articular face is quite small and sublateral. 
 The fibular facet is extensive, and the internal lateral well marked. 
 
 On the other hand the coracoid process is produced into a curved hook, 
 and is thus more largely developed than in other Proboscidians or Peris- 
 sodactyles. The neck is longer than in the other Proboscidians, and the 
 parietal bones appear to be narrowed by the approximation of the tem- 
 poral fossa, as in the Rhinocerus. Almost nothing however is known of 
 the structure of the skull. 
 
 The genera are two, as follows : 
 
 Penultimate molar unlike the last, with external crescent 
 and embracing ledge Bathmodon. 
 
 Three molars alike, with two transverse crests not meet- 
 ing within Metalophodon. 
 
 BATHMODON. Cope. 
 Proceedings American Philosopical Society, 1872, 417. 
 
 This genus was originally chiefly distinguished by the dentition ; at 
 present many other important peculiarities are added. First, as regards 
 the molar teeth ; the two transverse crests I find to be separated (not 
 united) at their inner extremities, by a narrow fissure. The anterior is 
 much the longer, and is curved ; its anterior wall slopes steeply down 
 to the narrow cingulum. The posterior is short, and straight, and bears 
 a crest. The numbers are I. 3 ; C. 1 ; P. M. 4 ; M. ? 3. 
 
 The entire mandible presents the following dentition ; I. 3 ; C. 1 . P. 
 M. 4 ; M. 3. The incisors radiate round the narrow extremity of the 
 trough-like symphysis, and have transversely expanded crowns. The 
 canine is inclined forwards and forms part of the same series. Its crown 
 is triangular in section, the outer face convex. In the males it was 
 enormously enlarged as indicated by a symphysis in my possession. The 
 anterior premolar approached the canine. The former teeth have an ex- 
 ternal chevron directed inwards, whose extero-superior surface of enamel 
 is acute cordate. Beside this is a little longitudinal ridge, which represents 
 
31 
 
 another chevron of the true molars. On the first of the latter, both 
 chevrons are developed, the posterior the least, both with their anterior 
 ridge boundaries lowered ; they sink entirely on the last two molars, which 
 become thus two crested as in those of some Tapiroids and the premolars 
 of Dinotherium. 
 
 The sternal segments are cylindric ; in one the articulations for the 
 hsetnpophyses project laterally, giving the piece a T-shaped form. The 
 atlas has a flat diaparapophysis, presenting its edges fore and aft ; the 
 arterial canal traverses it obliquely. The coracoid is double, having a 
 tuberosity on the edge of the glenoid cavity, find a prominent hook just 
 outside of it. The lumbar vertebra are quite short. The cuneiform 
 bone is narrow pyriform, with two triangular facets on one side, the 
 smaller being sublateral ; and one twisted over the other. The ungueal 
 phalanges are very short, somewhat flattened and with the terminal por- 
 tion transverse and rugose as in some toes of Palceytherium. 
 
 In the remains pertaining to this genus obtained by Dr. Hayden, there 
 are numerous individuals of apparently three species. Two of these are 
 larger and one smaller, the latter in part indicated by an individual with- 
 out epiphyses on the lumbar vertebrae. It presents marked difference in 
 the form of the astragalus atlas, scapula, etc. 
 
 a Larger species. 
 
 Astragalus everted in front ; nearly as wide as long ; 
 lower premolars narrower, more elevated and rugose ... B. radians. 
 
 Lower premolar broad, lower, and smooth B. semicinctus. 
 
 an. Smaller species. 
 
 Astragalus much wider than long, decurved in front. . B. latipes. 
 
 BATHMODON RADIANS. Cope. 
 
 Proceedings American Philosophical Society, 1872 (February 16), p. 
 418. Hayden's Geological Survey of Montana, 1871, 350. 
 
 In addition to the characters already assigned to this species as above 
 cited, I add the following : 
 
 The apex of the scapula is a massive flattened acumination with trun- 
 cate extremity. The spine is elevated and truncate next the glenoid 
 cavity, which is a wide oval, much produced at the coracoid margin. 
 The transverse process of the atlas is rounded distally and is about as 
 long as wide ; the surface for the axis is directed obliquely inwards. The 
 fibula has the inner sharp edge prolonged to the proximal end ; the form 
 of the latter is much as in Eobasileus. The astragalus is slightly concave 
 in both directions on the trochlear face, most so antero-posteriorly. 
 The anterior outline of the same is strongly and obliquely convex, and 
 the surface is produced sideways into a latero-anterior apex. The inner 
 malleolar border is thus very concave ; the outer is gently convex with a 
 long fibular facet. The posterior margin concave, the inner tuberosity 
 
32 
 
 prominent. The namcular facet is as broad as long, and nearly sessile, 
 being probably separated by a groove from the tibial. The cuboid facet 
 is subround, small and sublateral. The calcaneal situated diagonally 
 opposite each other. The antero-internal is twice as large as the other, 
 is transverse and truncate internally by a facet near the apex, at right 
 angles. The other calcaneal facet is subround. 
 
 Measurements. 
 
 M. 
 Length ramus mandibuli to anterior margin of coro- 
 
 noid process * 0.310 
 
 Length premolars and molars 218 
 
 " last molar crown 040 
 
 Width " " " 030 
 
 " " premolar crown 018 
 
 Length last premolar 025 
 
 Width symphysis at canines 045 
 
 Diameter canines <5 028 
 
 9 023 
 
 Length exposed portion incisor 2 026 
 
 Width crown " " 0245 
 
 Length diapophysis atlas 047 
 
 Width " " 056 
 
 " facet for axis 053 
 
 " glenoid cavity scapula (straight) 086 
 
 Length coracoid from inner basis 045 
 
 11 proximal articulation fibula 027 
 
 " distal " " 042 
 
 Diameter shaft " 022 
 
 Total length astragalus (fore and aft) 072 
 
 " width " 065 
 
 Length uavicular facet 045 
 
 Width " " 034 
 
 11 cuboid " 025 
 
 Length " " 023 
 
 * * anterior calcaneal do 040 
 
 Width " " 024 
 
 Length posterior " 021 
 
 " fibular (axial) 043 
 
 The teeth are slightly rugose, and the inferior canines show a tendency 
 to imitate the form of the incisors in a slight basal angular expan- 
 sion of the crown. This forms an approximation to the tapirs. The 
 middle pair of incisors is directed outwards, is the smallest, and like 
 all the others has the roots much exposed. 
 
 This species was originally described from teeth of the upper jaw. I 
 have since obtained the entire mandible (except the angles) taken out at 
 
33 
 
 the same place and near the same time. The size, color, etc., would 
 indicate that they belong to the same individual. Accompanying the first 
 specimens were many bones of individuals of different sizes, which I 
 learn from the the finder were all taken from within a short distance of 
 each other. Many of them belong to the same species, as the jaws and 
 teeth, and I have described as such those that relate properly to them as 
 to size, mineral appearance, etc. 
 
 The smaller specimens belong also to several individuals, and possibly 
 to more than one species. I describe them together, but regard the 
 astragalus as the primarily distinctive bone. 
 
 BATHMODON SEMICINCTUS. Cope. 
 
 Proceedings American Philosophical Society, 1872, p. 420. Loxolopho- 
 don, semicinctus, Cope, 1. c. 
 
 The tooth on which this species was based shows a near relation to the 
 corresponding one of B. radians. 
 
 BATHMODON LATIPES. Cope. Species nova. 
 
 Established on atlas axis, dorsal and lumbar vertebra, scapula, hume- 
 rus, phalange, femur, astragali, etc., of a specimen found with the B. 
 radians. 
 
 The transverse process of the atlas is stouter and less flattened at the 
 base than in B. radians. The axis is but little oblique and has a low 
 obtuse hypapophysis below. Its form is much as in the larger species, 
 being rather elongate, but shorter than in Rhinocerus and other Perisso- 
 dactyles. The dorsals and lumbars are short and plane ; the former are 
 obtusely, the latter acutely keeled below. The head of the femur has 
 no ligamentous fossa. The astragalus is considerably broader than long, 
 the apex turned outwards in front of the inner malleolus, being especially 
 produced. The tibial face is concave transversely, and convex antero- 
 posteriorly at the front, plane behind. There is a posterior submarginal 
 foramen, which is not bridged over in one specimen, producing a deep 
 notch. The navicular facet has considerable transverse extent, and the 
 anterior side of the bone is more transverse than in B. radians. The 
 calcaneal facets are diagonally opposite to each other ; the outer is sub- 
 round, the inner anterior narrow and transverse. It differs in the two 
 specimens, the perforating foramen not being bridged over in the one (the 
 type) with the similar posterior interruption described above. This may 
 be due to fracture. The only ungueal phalange has the articular face 
 not quite sessile on the transverse rugose free extremity. 
 
 Measurements. 
 
 M. 
 
 Diameter diapophysis atlas (fore and aft) 0.036 
 
 " axial facet of " 034 
 
 " centrum axis (transverse) 080 
 
 " (vertical) 037 
 
 Length " "to odontoid 057 
 
Width neural canal do 030 
 
 (fore and aft 040 
 
 Diameter of centrum of dorsal J vertical (total) 043 
 
 ( transverse 051) 
 
 neural arch of same { S^;;;.V. ! ! ! IV! ^ 
 
 i antero-posterior '041 
 
 " centrum of lumbar J vertical (total) 050 
 
 ( transverse 063 
 
 " head of femur 060 
 
 Length astragalus fore and aft 050 
 
 Width 065 
 
 Length navicular facet 049 
 
 Width " " 020 
 
 " cuboid " 018 
 
 Length " " 016 
 
 Width (fore and aft) anterior calcaneal 018 
 
 Length posterior calcaneal facet 022 
 
 " flbular (axial) 041 
 
 li terminal phalange 012 
 
 Width do proximally 015 
 
 " distally 030 
 
 Diameter glenoid cavity scapula { 
 
 nr.. . . . . 
 
 From the beds of the Green River epoch near Evanston, Utah (now 
 Wyoming). 
 
 METALOPHODOK Cope. 
 
 Proceedings American Philosophical Society, 1872, p. 542. (Pub- 
 lished September 20th. ) 
 
 In distinguishing this genus from Batlimodon, I stated that the differ- 
 ences were in the dentition so far as known ; i. e. that the crests of the 
 true molars are not united internally and that the premolars are two not 
 three crested. I would now add to the characters, that there are three 
 molars on each side, with transverse crests, which do not unite at the 
 apex, except in the case of the anterior, when they are slightly connected. 
 In Bathmodon there is but one such tooth, the posterior. The inner or 
 third crest of the posterior premolar of that genus is only a cingulum, 
 and is not probably a generic character. 
 
 METALOPHODON AKMATUS. Cope. Loc. cit. 
 
 This species is represented by the greater part of the dental series of 
 both jaws, which 1 took from a decayed cranium myself, and can thus be 
 assured of their mutual relations. One of the true molars at least, 
 belonged to the milk series, as indicated by the unworn crowns of the 
 successional teeth accompanying. Some of the premolars are but little 
 worn. Referring to my original essay for the general description, I append 
 exact 
 
35 
 
 Measurements of the Teeth-. 
 
 M, 
 
 Total length of a superior incisor 057 
 
 Length crown (inner face) superior incisor 015 
 
 Width " (oblique) " " 020 
 
 " " " inferior " 023 
 
 Length " (inner face) " " 018 
 
 Width canine .030 from tip 020 
 
 ' ' posterior molar 039 
 
 Length " 028 
 
 Elevation posterior crest do 016 
 
 Width anterior true molar * . . .035 
 
 " premolar 028 
 
 Length " 0215 
 
 ". (first) 016 
 
 Width " 008 
 
 Length " (inferior) 024 
 
 Width " " 020 
 
 " penultimate lower molar .023 
 
 Length " " " 037 
 
 It is not certain that the last named species of Bathmodon does not be- 
 long to this genus. All three are distinct from the M. armatus, the lat- 
 ter though young, being considerably larger than BatJmwdon latipts, 
 
 APPENDIX. 
 
 The materials on which the preceding determinations are based, were 
 obtained by the Geological Surveys conducted during 1871-2, by Prof. F, 
 V. Hayden, U. S, Geologist, 
 
 The papers descriptive of fossils from the Wyoming basin published by 
 the writer during the jjear 1872, were issued at the following dates : 
 
 On Bathmodon, an extinct genus of Ungulates, February 16th. 
 
 On a new genus of Pleurodira from the Eocene of Wyoming, July llth. 
 
 On the Tertiary coals and fossils of Osino, Nevada, July 29th. 
 
 Descriptions of some new Vertebrate from the Bridger Group of the 
 Eocene, July 29th. 
 
 Second account of new Vertebrata from the Bridger Eocene, August 3d. 
 
 Third account of new Vertebrate from the Eocene of Wyoming Terri- 
 tory, August 7th. 
 
 On the existence of Dinosauria in the Transition beds of Wyoming, 
 near August 12th, 
 
 Notice of Proboscidians from the Eocene of Southern Wyoming, 
 August 19th, 
 
 Notices of new Vertebrat.a from the upper waters of Bitter Creek, Wy- 
 oming Territory, August 20th, 
 
 Second notice of extinct Vt'rtttw.tes from Bitter Creek, Wyoming, 
 August 22d. 
 
 On the Dentition of Metalophodon, September 2()th- 
 
On a, new Vertebrate genus from the northern part of the Tertiary 
 Basin of Green River, October 12th. 
 
 Descriptions of new Extinct Reptiles from the Upper Green River 
 Eocene Basin, Wyoming, October 12th. 
 
 The above essays were distributed widely at the above dates, except- 
 ing that on Metalophodon. 
 
 In an article on Uintatherium mirabile, Prof. O. C. Marsh criticizes the 
 statements made in some of the above essays, denying their accuracy. In 
 reply to such of them as are not frivolous, I would say that I make no 
 corrections of them at present (except one, which I made prior to the 
 appearance of his remarks), but show that his statements were based on 
 species different from those described by me. These he has either not 
 seen or not studied. 
 
 In applying the law of priority in nomenclature, I have endeavored 
 to practice the rules adopted by the majority of students, and which I 
 believe to be founded in justice. They are as follows : 
 
 (1.) Priority reposes on date of publication not on reading of memoirs. 
 
 Note- What is necessary to determine the time at which a discovery of 
 scientific truth is made, is the earliest reliable evidence of such dis- 
 covery. As verbal and written assertion cannot be preserved inviolate, 
 printing is necessary to secure the record from change. The earliest 
 evidence of such printing is that offered by printers, who issue the work, 
 and any person who receives it from them. It is then published. 
 Ordinary books bear such date of publication, whether distributed, sold, 
 or standing on the author's shelves. 
 
 (2.) In order that a specific name be adopted it must be associated with 
 a description of the object to which it refers. 
 
 Note. The necessity of this rule is self evident, since the only value of 
 scientific literature is to convey definite information, which a name does 
 not. Moreover the worst description will generally embrace at least one 
 peculiarity of a species, which will serve to fix the name, but a label, or 
 the specimen itself, may readily be lost or transposed in a museum. 
 Further, in writing descriptions it is necessary to introduce as many 
 points as possible, not only to distinguish the species from those already 
 known, but from those which may in future be discovered ; for it is with 
 these that difficulties chiefly arise. 
 
 (3.) In order that a generic name be adopted, it also must be accom- 
 panied by a description. 
 
 Note. Since naturalists differ to some extent as to what they term a 
 genus, some may be disposed to doubt the expediency of this rule, but 
 its importance to science appears to me greater than in the case of species. 
 In the first place, scientific literature being designed for the communi- 
 cation of exact knowledge, it is essential that its words should represent 
 ideas. The genus is as definite a mental conception as a species, to the 
 scientific, thinker, and in proposing a name, should also express what it 
 
37 
 
 represents in his mind. Without such expression it is safe to suppose 
 that no such idea exists ; and if so, the name should be regarded as a cipher 
 in the literature of science. 
 
 That certainty as to the limits and hence definition of a genus is not 
 at once attainable, is no objection to the above rule. By study of known 
 forms definite knowledge of generic characters may be attained by 
 proper analysis. But whether correct or not, a generic description 
 expresses something definite, and gives the name a currency which 
 should remain as a record of honest work. 
 
 The evils which come from the opposite course are numerous. They 
 are : 1st. Names without description are unintelligible, and communicate 
 nothing. 3d. They serve to conceal the ignorance or incompetency of 
 their authors. 3d. If allowed, they open the door to the introduction of 
 names on geographical and stratigraphical grounds ; a slovenly pratice, 
 indulged in by a few paleontologists, and properly denounced by Fal- 
 coner, as assuming at the outset what it is the design of the science to 
 prove. The same practice attempted in zoology has been utterly con- 
 demned, as for example in the case of the System Reptilium, published in 
 1843. Here pages of generic names may be found, with type species indi- 
 cated, which have no authority whatever. 4th. The practice lays the 
 science open to the inroads of charlatans and scientific pirates, who seek 
 to impose a nomenclature without the labor of discovering a system or 
 describing its objects. 5th. As the genus is a more important conception 
 in palseontological science than the species, it is more important that what 
 its name represents should be clearly understood, otherwise generaliza- 
 tions become impossible or incomprehensible. 
 
 (4.) When a supposed genus is found to consist of several, and the 
 author has stated what he regards as the type of the former, that 
 species must retain the original name. Where the type of the original 
 genus is unknown, the original name must attach to that genus which 
 remains, after subtraction of the others found to be embraced in the 
 original assemblage. 
 
 Note. This rule is adopted as doing less violence to long accepted views 
 and practice in nomenclature than any other. While recognizing the 
 work of the original author, it also preserves record of the labor of those 
 who have determined the true divisions with more exactitude. 
 
 EXPLANATION OF PLATES. 
 
 PI. 1. LoxolopJwdon cornutus, Cope, profile natural size. 
 PI. 2. The same from the front. 
 PI. 3. Superior view of the same. 
 
 PI. 4. Inferior view. 
 Published March 14th, 1873. 
 
AmJ>h&>s.Soc Vol. HZ. 
 
 Plate 
 
 rL comulux Cope . 
 
 V6 na. Size-. 
 
Proceed Am.Pkilos. Soc. Vol.Hff. 
 
 BlateZ. 
 
Phiks. Soc. Vol. Jfll. 
 
 f '-. 
 
 loxolop/iodon/ c 
 
Proceed.Arw.PhJJ0s. So* VbfrXni. 
 
 Plate 4. 
 
 '/# n-a. Size.