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TRANSACTIONS
OF THE
AMERICAN PHILOSOPHICAL SOCIETY
HELD AT PHILADELPHIA
FOR PROMOTING USEFUL KNOWLEDGE
VOLUME XXII_NEW SERIES
PHILADELPHIA
PUBLISHED BY THE SOCIETY
1925

LANCASTER PRESS. INC.
LANCASTER, PA.

Contents of Volume XXII
ARTICLE I
175 Parabolic Orbits and other Results deduced from over 6,200 Meteors. By
CHARLES P. OLIVER..
5
ARTICLE II
The secular Variations of the Elements of the Orbits of the four Inner Planets
computed for the Epoch 1850.0 G. M. T. By ERIC DOOLITTLE.
37
ARTICLE III
Tertiary Vertebrate Faunas of the North Coalinga Region of California. By
JOHN C. MERRIAM.
191
ARTICLE IV
The Feeding Habits of Pseudomyomine and Other Ants. By W. M. WHEELER
AND J. W. BAILEY.
235
ARTICLE V
A Review of the Doradidae, a Family of South American Nematognathi, or
Catfishes. By CARL H. EIGENMANN.
280
Title


THE FEEDING HABITS OF PSEUDOMYRMINE AND OTHER ANTS.
279
PLATE IV.
Fig. 23. Portion of larval pellet of Pseudomyrma gracilis (var. nov.), showing fragments of insects
and pollen. X 58.
Fig. 24. Portion of larval pellet of Pseudomyrma filiformis, showing fragments of insects and spores.
X 78.
Fig. 25. Portion of larval pellet of Pseudomyrma championi, showing fragments of insects, spores and
pollen. X 78.
FIG. 26. Portion of larval pellet of Pseudomyrma flavidula, showing fragments of insects, hyphæ and
spores. X 330.
Fig. 27. Portion of larval pellet of Pseudomyrma gracilis var. mexicana, showing fragments of insects
and hyphæ. X 58.
Fig. 28. Portion of larval pellet of Pseudomyrma gracilis, showing fragments of insect. X 78.
Fig. 29. Portion of larval pellet of Tetra ponera allaborans, showing fragments of insects and pollen.
X 78.
Fig. 30. Portion of larval pellet of Pseudomyrma gracilis var. mexicana, showing fragments of insect.
X 78.
Fig. 31. Portion of larval pellet of Pseudomyrma gracilis var. dimidiata, showing fragments of insects.
X 58.
PLATE V.
Fig. 32. Portion of larval pellet of Pseudomyrma gracilis var. dimidiata, showing spores of different
types among others those of Ravenelia distans A. & H. X 330.
Fig. 33. Portion of larval pellet of Pseudomyrma rufomedia, which is composed entirely of pollen
and spores. X 330.
Fig. 34. Same as Fig. 32. X 58.
Fig. 35. Portion of larval pellet of Pseudomyrma species, from Patulul, Guatemala, showing dirt and
other detritus. x 58.
Fig. 36. Portion of larval pellet of Pseudomyrma gracilis var. mexicana, which is composed entirely
of spores and hairs. X 330.
Fig. 37. Portion of larval pellet of Pachysima aethiops, showing plant hairs, spores and dirt. X 58.
Fig. 38. Portion of larval pellet of Pseudomyrma belti, showing pollen. X 58.
Fig. 39. Portion of larval pellet of Pseudomyrma decipiens, which is composed almost entirely of
spores. X 330.
Fig. 40. Portion of larval pellet of Pseudomyrma sericea var. fortis, showing hyphæ and fragments of
medullary tissue from myrmecodomatia of Triplaris macombii. X 330.
19

ARTICLE 5.
A REVIEW OF THE DORADIDÆ,
A FAMILY OF SOUTH AMERICAN NEMATOGNATHI,
OR CATFISHES.1
(Plates I-XXVII.)
BY CARL H. EIGENMANN.
a
INTRODUCTION.
The present is one of a series of monographs dealing with the families and sub-
families of the freshwater fishes of South America. Preceding monographs are:
(1) A revision of the South American Nematognathi, or Catfishes. Occasional Papers
California Academy Sciences, 1890, Vol. I. In coöperation with Rosa S. Eigenmann;
(2) The Gymnotid eels of tropical America. Max Mapes Ellis, Mem. Carnegie Mus.,
1913, Vol. VI; (3) The Cheirodontinæ, a subfamily of minute characid fishes of South
America. Mem. Carnegie Mus., 1915, Vol. 7; (4) The American Characidæ. Mem.
Mus. Comp. Zool., 1917–1925, Parts 1, 2, and 3 issued so far; (5) The Pygidiidæ, a
family of South American Catfishes. Mem. Carnegie Mus., 1918, Vol. 7.
The present paper is based principally on the collections in the Museum of
Indiana University.
The material was gathered during (a) my visit to British Guiana, 1908; (b) to
Colombia, 1912; (c) the trip of Dr. W. R. Allen to the Peruvian Amazon, and (d) the
trip of Mr. N. E. Pearson with the Mulford Expedition to Bolivia. In part it was
received in exchange from other museums. In 1888 I examined the collection of
Doradids in the Museum of Comparative Zoölogy (Occasional Papers Cal. Acad. Sci.,
I, 1890), and more recently those of the Carnegie Museum. I am indebted to the
Carnegie Museum, the Museum of Comparative Zoology, the Museum of the Phila-
delphia Academy of Natural Sciences and the Tropical Research Station under the
direction of Dr. William Beebe for the privilege of examining some of the Doradids
in their collections. Dr. Thomas Barbour was kind enough to reëxamine Hoplodoras
uranoscopus described by Mrs. Eigenmann and myself thirty seven years ago. Dr.
Alipio Ribeiro generously had Sr. E. Cruzlima make drawings of the types of Mega-
lodoras libertatis and Anadoras insculptus. Unless otherwise indicated the photo-
graphs were made by the author, mostly based on anatomical preparations made
by him. The drawings were made by Eugene N. Fischer (Plate XII), Dr. Clarence
1 Contribution from the Zoological Laboratory of Indiana University, No. 198.
280

A REVIEW OF THE DORADIDÆ.
281
Kennedy (various details in the text figures), and particularly by W. S. Atkinson of
Stanford University.
The numerous anatomical preparations enabled me to resurrect and re-define
many of Bleeker's abandoned genéra and to describe a number of other genera as
new. The examination of the air-bladders demonstrated such an unexpected,
amazing and riotous divergence that it is regrettable that not all of the species could
be examined. So many species are known only from the types that probably many
other forms are undiscovered, which makes rather elaborate if not complete illustra-
tions justifiable and desirable.
POSITION OF THE DORADIDÆ AMONG OTHER SOUTH AMERICAN FISHES.
South America is very rich in freshwater fishes. As in North America, Europe,
Africa and India, the Ostariophysi are dominant in South America. There are
series of families of Heterognaths or Characins, another series of peculiar eels, the
Gymnonoti and another series of Nematognaths or Catfishes. Of the fifteen families
of catfishes found in South America, one family extends north to Central America,
one is found in warm seas, the rest are all peculiar to South America.
Class
PISCES
Superorder or Series OSTARIOPHYSI (Plectospondili)
Orders NEMATOGNATHI—HETEROGNATHI-GYMNONOTI.
South American Families of Nematognathi and their distribution:
DIPLOMYSTIDÆ (Temperate South America),
ARIIDÆ (Warm seas and rivers),
AUCHENIPTERIDÆ (Tropical South America),
DORADIDÆ (Tropical South America),
AGENEIOSIDA (Tropical South America),
HELOGENIDÆ (Tropical South America),
HYPOPHTHALMIDÆ (Tropical South America),
PIMELODIDÆ (Central America and Tropical South America),
BUNOCEPHALIDÆ (Tropical South America),
ASPREDINIDÆ (Tropical South America, in part marine),
PYGIDIIDÆ (South America),
NEMATOGENYIDA (Chile),
CETOPSIDÆ (Lowlands of Tropical South America),
ASTROBLEPIDÆ (Andes from Panama to Titicaca),
CALLICHTHYIDÆ (Tropical South America, chiefly lowlands),
LORICARIIDÆ (Tropical South America, lowlands and mountains).

282
A REVIEW OF THE DORADIDÆ.
THE NATURE OF THE DORADIDÆ.
Diagnostics.—The Doradidæ are a family of catfishes, Nematognaths, peculiar
to tropical South America. They are distinguished from all other Nematognaths by
the presence of a series of plates along the sides, each with a strong, median, backward-
directed spine, sometimes supplemented by smaller spines on the surface of the plate.
They are furthermore distinguished from all but the Auchenipteridæ by the exag-
gerated development of the parapophyses of the fourth vertebra, associated with
a
T
T
A.TV
A.TV
P.IV
А
B
Fig. 1. The fourth vertebra of Pterodoras granulosus. A, From below, showing the anterior (A. IV) and posterior (P.)
lateral processes. The anterior process with the oval disks which fit into pockets of the air-bladder. B, From above, the body
of the vertebra partly cut away to show the Weberian bones. T = tripus or malleus. Compare with Fig. 11.
the air-bladder and the Weberian apparatus. The anterior lateral process of the
fourth vertebra arises as a thin, firm, flexible plate and ends in a large, circular, disk-
like or conical plate so closely attached in an indentation of the air-bladder that it
frequently parts company with the basal part and remains attached to the air-bladder,
when the latter is removed. The disk is of very different texture from that of the
flexible, compact, basal part to which it is attached. The Doradidæ further agree
with the Auchenipteridæ in the solidly united bones of the skull, nuchal shields and
dorsal plate. The nasal openings are remote. The gill-membranes united with
the isthmus.
The species reach an extreme length of a meter. Most of them are much smaller.
Structural radiation. There are two groups of species arranged under “a” and
"aa" in the key to the genera. In the broad-breasted species, “a,” in which the
head is more depressed, the premaxillary is normal, provided with bands of teeth,
the mental barbels simple. In the narrow-breasted species the head is compressed,
a

A REVIEW OF THE DORADIDÆ.
283
rather than depressed, the snout narrow, sometimes prolonged, conical. In these the
premaxillary is subcircular, with very few or no teeth. Frequently the barbels are
fimbriated and can be folded forward and used as a screen over the small mouth.
In the broad-mouthed species the anterior nostril is very near the lip, in the
conical, prolonged-snouted ones the anterior nostril is always a considerable distance
from the lip. There are no nasal barbels in any of the species.
The species best fitting the North American conception of a catfish is Pterodoras
granulosus (Plate VIII). It has a broad ethmoid and broad premaxillaries, which
bear wide bands of teeth. While in general appearance this species seems most
conventionalized, the structure of its air-bladder indicates that it is far from primitive.
Judging by the air-bladder and by the distribution, Centrochir crocodili and Fran-
ciscodoras marmoratus are the oldest and most nearly like the original Doradids.
A very close rival to them is the widely distributed Platydoras costatus (Plate IX).
Fins. The dorsal is usually composed of one spine and six rays. In the species of
Nemadoras bachi, Agamyxis pectinifrons, and in Acanthodoras, it is 1, 5, even I, 4 in
some specimens of A. cataphractus and in castaneoventris, which is probably a synonym
of the cataphractus. It is situated immediately behind the nuchal shield. The dorsal
spine may be slender or large and heavy, serrate on both edges, serrate only in front,
or without serræ. The spine, if without serræ, has longitudinal grooves and ridges.
The anal is short, with from 10 to 16 rays. The adipose fin is present in all but
Physopyxis. Usually it is well defined and short. In the larger, heavily armored
species it is usually not well defined, prolonged forward as a heavy and scarcely
flexible keel, extending from the adipose toward the dorsal. The caudal may be
rounded, truncate, emarginate or deeply forked. The ventrals are rounded, without
marked peculiarities. The pectoral spine is in some species notably heavy and large,
in others long and slender. It is always serrate on both margins, sometimes also
on the dorsal surface.
Bones of the head.—The bones of the upper surface of the head are granular or
striated, covered with very thin skin. They are united by sutures into a solid shield
or plate. The sutures can frequently be seen only with a lens. In the numerous
figures the sutures were traced and marked under a binocular dissecting microscope.
The bones are uniformly numbered in the different figures. The bones of the top
of the skull united by sutures are (2) the ethmoid, (3) lateral ethmoid, (5) frontals,
(6) sphenotic, (7) pterotic, (8) supraoccipital, (9) epiotic and three elements (X, Y, Z)
of the dorsal scutes, which are expanded ends of interneural spines.
The skull varies from nearly flat in Acanthodoras to sharply roofshaped in
Trachydoras (Plates II and IV). The suprascapula (10) is ankylosed to the pterotic
.

284
A REVIEW OF THE DORADIDÆ.
(7) and epiotic (9). It entirely excludes the epiotic from the margin of the skull in
the broad-snouted species and in Pseudodoras. In all the species in which the epiotic
(9) is connected with the first lateral scute by a process (9a) it forms part of the
margin of the shield and the supraclavicle (10) is but narrowly in contact with the
epiotic (9).
In the broad-headed species the fontanel is a small, oval opening between the
anterior end of the frontals (Plates II to IV), sometimes extending into the ethmoid.
In extreme cases the fontanel is reduced to sub-circular (Plate II, Fig. 3) and may be
entirely occluded. In the narrow-headed species the fontanel is more elongate. It
А
B
13
12
19
18
75
20
C
FIG. 2. A, Preorbital and suborbitals of Astrodoras asterifrons. B, Preorbital and suborbitals of Pseudodoras niger.
C, Membrane bones of the right side of Pseudodoras niger. Notations: 4, Preorbital; A and B, suborbitals; 12, maxillary; 13,
palatine; 14, mesopterygoid; 14a = metapterogoid; 15, quadrate; 16, preopercle; 17, interopercle; 18, opercle; 19, hyoman-
;
dibular.
moid and into the occipital, with a narrow bridge in the posterior third of the frontal.
reaches its maximum in Leptodoras (Plate II, Fig. 2) where it extends both into the eth-
A very slender rod, the nasal, is attached by ligament to the margin of the
ethmoid, between the ethmoid and the nasal cavity. It is marked D in the plates,
but is mostly obscure.
There is but little variation of the same bone in the different species. The
greatest variation is found in the epiotic and in the region in front of the eye, in the

A REVIEW OF THE DORADIDÆ.
285
preorbital bone (4) and the suborbital chain. The preorbital bone (4) is always more
or less fan-shaped. The pointed anterior end of the bone may be in contact with
the maxillary and premaxillary. It may not reach so far. In a few species, Pseudo-
a
7
5
2
10
B
12
14
А
2
19
14a
12
16
15
17
B
Fig. 3. Platydoras costatus. A, With the preorbital and suborbitals. B, With the preorbital and suborbitals removed.
1, premaxillary; 2, ethmoid; 3, lateral ethmoid; 4, preorbital; 5, frontal; 6, sphenotic; 7, pterotic; 8, supraoccipital; 9, epiotic;
10, supraclavicle; 12, maxillary; 13, palatine; 14, mesopterygoid; 15, quadrate; 16, preopercle; 18, opercle.
doras niger, it is joined to the lateral shoulder of the ethmoid, the ectethmoid. It is
procumbent in the larger species, its expanded edge smooth (Megalodoras, Plate VI,
Figs. 3 and 4) or scalloped and covered with skin. In other species it is serrate or finely

286
A REVIEW OF THE DORADIDÆ. .
pectinate (Agamyxis, Text-fig. 14, Astrodoras, Plate III), the pectinate edge being
raised to form a crest in front of the posterior nostril. The suborbital varies with the
size of the eye. In some species, those with minute eyes, the first suborbital lies under
the preorbital and does not form part of the orbital margin. In other cases all three
suborbital bones form the orbital margin and are of about uniform width. In some
cases they are feeble and lie imbedded in the skin; in others they are of unequal size
and one or all of them thick, granular.
C..
CO.
CE
A
B
с
D
CL
Co..
E
F
Fig. 4. Clavicle, coracoid and pectoral spine in Megalodoras irwini: A, from below; B, from above; Pterodoras granulosus:
C, from below; D, from above; Doras micropæus: E, from below; F, from above.
The opercles may be covered with smooth skin, but usually the opercle (18 in the
figures) is at least partly granular or striate, and sometimes the interopercle and pre-
opercle are notably granular (Trachydoras, Plate XVIII).
The palatine (13) is rod-shaped, in contact with the maxillary in front (12) lying
above the mesopterogoid (14), which connects the metapterogoid (14a) with the
lateral ethmoid (3). The size of the palatine varies with the length of the snout,
reaching its maximum in Doras micropæus (Plate XXIV), Leptodoras (Plate XXIV)
and Pseudodoras (Plate XVII).
The shoulder girdle.—The clavicle and coracoid are always united with their
fellows of the opposite side by an interlocking suture into a solid plate, provided with
a process extending from the coracoid backward below the pectoral, and another
process usually longer than the coracoid from the clavicle backward above the pectoral,
the so-called humeral process.
a

A REVIEW OF THE DORADIDÆ.
287
Rarely the coracoid process is exaggerated and extends as far as the humeral
process (Trachydoras paraguayensis, cl. and co., Plate XVIII), or even much further
(Physopyxis lyra, Plate 16). The surface of the humeral process may be granulate
or the granules may be enlarged into spines along a series, particularly toward the tip.
In the more exaggerated forms the spiny humeral process and the pectoral spine
form a scissors-like apparatus (Plate XXV, Fig. 3).
The upward projecting flanges of the coracoid and the inward flanges of the
clavicle are very different in different species. In the narrow-breasted genera they
are extensive and form a dividing wall between the gill-cavity and the parts behind.
&
tr.
St-
p.lt
ce
8a
10
cc.
Co.
Fig. 5. Cross section of Trachydoras atripes (I. U. M. 16006) just behind the bony diaphragm formed by the flanges
of the coracoid, co., clavicle, cl., supraoccipital 8, exoccipital 86, basioccipital 8a; epiotic 9, supraclavicle 10; the broken vertebra v,
the process of the fourth vertebra X.
In these species the effect is heightened by the expansion of the basioccipital into a
thin plate extending downward. The partition or diaphragm formed by the flanges
of the clavicle, coracoid and basi- and exoccipital reaches its maximum in the species
of Trachycorystes (Text-fig. 5). The opening is just sufficient for the passage of the
alimentary canal, being much smaller than the pupil. In Trachydoras paraguayensis
the downward plate of the basioccipital and supraclavicle actually overlap, passing
behind the processes of the clavicle and coracoid. In this species the opening is not
visible looked at from straight behind; the alimentary canal is a siphon. The parti-
tion is least developed in Megalodoras and Lithodoras.
In most of the species the lower surfaces of the coracoid-clavicle are covered with
the erector muscles of the pectoral spine and these with skin (cl. and co. in the ventral
views on many of the plates); in a series Anadoras grypus, weddelii (Plate XV), Ambly-

288
A REVIEW OF THE DORADIDÆ. .
doras monitor (Text-fig. 15), A. hancockii (Plate XIII) and Physopyxis lyra (Fig. 1,
Plate XVI), there is a decreasing space for muscles and an increasing granulation of
the bones, covered with very thin, scarcely perceptible skin.
a
3
2
С
D
A
ws
E
B
F
co
G
Fig. 6, A, B, D. Pectoral lock of Megalodoras irwini. A, Pectoral spine depressed; B, the same erect; D and F, the
basal end of the pectoral spine, D from the axillary edge, F looking directly at the base of the spine. Part of the clavicle cut
away to the left of the spine in A, to show the groove in which the outer flange of the spine moves. C and E, the basal end of
the pectoral spine of Pseudodoras niger, to correspond with D and F. G, the right pectoral spine of Platydoras costatus.
Lock of the pectoral spine.—A most striking feature of the Doradidæ is the elabo-
rateness of the pectoral spine and everything associated with it, its muscles, and the
adaptation of the bones for their attachment, the coracoid and clavicle.

A REVIEW OF THE DORADIDÆ.
289
As in other Nematognaths the pectoral spine can be erected and locked at any
stage of erection. Though in type the lock is not different from that in some other
Nematognaths it may not be out of order to redescribe it.
The left pectoral joint and lock can best be imagined by using the right hand
and arm as a model. The arm would represent the spine (Text-fig. 6), the thumb
(1) and pointer finger (2) would represent two processes engaging between them a
portion of the coracoid, the tip of the thumb turning in a socket in the lower outer
surface of coracoid as a fixed point, the tip of the forefinger moving in a short groove
of the inner surface of the coracoid.
The middle finger is grooved along its entire lower surface, fitting over a ridge
of the coracoid, the end of the middle finger (3) impinging upon the clavicle.
The ring and little fingers (4 or y) are greatly expanded sidewise into a curved
blade projecting around the dorsal surface of the spine, moving in a deep, curved
groove in the expanded, laterally-projecting portion of the clavicle. In erection and
depression the spine revolves on two axes. In the main movement, the erection
and depression, the spine moves about the axis provided by the ridge over which the
grooved lower surface of the spine fits. The second axis extends from the thumb
to the tip of the spine and movement about it results in the tortion of the spine. The
thumb (1) moves, twists in the socket, the pointer finger moves in a short, shallow
groove in the coracoid, the expanded flange (4) moves in a much longer, deeper,
curved groove in the clavicle. In order to depress, the spine must not simply revolve
on the transverse (middle finger) axis; it must also undergo a slight tortion about the
longitudinal axis of the spine with the end of the thumb as the pivot. The moment
the twisting in the longitudinal axis stops, the spine becomes locked in whatever
stage of erection, because the outer groove is curved.
The spine cannot be depressed in a preserved or living specimen rotated about
the ridge of the coracoid by simply employing a force directly toward depression.
The spine will break off sooner than go down. It can easily be depressed by twisting
the spine, key-fashion; the left one clockwise, the right one contrary, at the same time
that force is being applied to depress it.
The above description was made with the left side of Pseudodoras niger in mind.
There are small modifications from this type in other species.
The pectoral spines and everything connected with them, the serration, the high
development of the humeral process, frequently with spines opposed to those of the
pectoral spine, the great development of the clavicle and coracoid to provide attach-
ment for the pectoral muscles, the expansion of the clavicle to provide the elaborate
groove in which the flange of the spine moves, all point to functions of the spine beyond

290
A REVIEW OF THE DORADIDÆ.
and in addition to that as a defensive organ. It appears as though the entire evo-
lution of the Doradidæ centered in the pectoral spine, which is well shown in Plate
XXV.
Lock of the dorsal spine.—The dorsal spine may also be locked in various positions.
It can always be erected, but depressed only when the “latch” is raised. Its articular
surface and lock involve two interneurals, that below the spine itself, and that below
the “latch," the modified spine in front of it, and the modified first ray or spine which
forms the latch. In D, micropæus the anterior interneural involved (Fig. 7, E, INT.
I.) consists of a median plate (m.pl) and lateral flanges (f) continuous with similar
flanges (the parapophysis) of the fourth vertebra. The tip of the first interneural in
front of its flange is expanded to form the “Y” element of the dorsal plate.
a
a
<<<
e
e
D
os
-d
B
C
Fig. 7. The base of the dorsal spine of Pseudodoras, A, from in front; B, from the right side; C, from behind; D, from
below. Kennedy, del. a, the anterior articular surface in contact with the second interneural which passes through the opening
d; e, the opening through which blood vessels, nerves, etc., enter the spine; 1, the lateral articular surfaces bearing on the lateral
flanges of the second interneural.
Behind the flange the tip of the first interneural is transformed into a two-
faceted, smooth, articular surface (b, Text-figs. 7 and 8) facing forward and upward.
Looked at from above and in front it resembles very much a partially unfolded young
leaflet. The two-pronged fulcrum (marked 0 and E or D.S.I), the modified first
spine of the dorsal, straddles this. The second interneural has a pair of similar
median lateral ridges which are expanded at the tip and provided with articular
surfaces (K, Text-fig. 8) on which the lateral ends (l) of the dorsal spine move. The
anterior part of middle plate of the second interneural is developed into a concave
articular surface (c, Figs. 8 and 9) in which the anterior, mesial end (a) of the dorsal
spine moves.
A finger-like prolongation from the middle process of the interneural is crooked
backward through an opening in the dorsal spine (B, Text-fig. 7). It meets a similar

A REVIEW OF THE DORADIDÆ. .
291
forward-crooked process from the posterior part of the second interneural, the two
uniting to form a ring by which the dorsal spine is fastened to the second interneural.
As long as the spine is erect and the crooked fulcrum is down as in Text-fig. 9, A, E,
and G, the spine is locked, erect. The spine can be depressed when the fulcrum 0
is raised as in D and F.
C-
A
b
b
INT.I
D
mp?
f
E
B
с
Fig. 8. A, Base of dorsal spine, and B to E, elements of the dorsal lock of Pseudodoras niger. The right in figures A, B,
and E, are anterior. A, base of spine from the right; B, tip of first and second interneural from the side; C, tip of first interneural
from in front. The tip of the second neural spine that passes through the dorsal spine at d is broken off. D, the "latch," the
fulcrum, or first dorsal spine from in front. E, the same from the side.
In Megalodoras irwini a median partition or interneural septum extends down
from the “X” element of the dorsal plate (F and G, Fig. 9). In D. micropæus there
is no such partition (D and E, Fig. 9). There are many gradations in the development
of the median partition between these two extremes.
An interneural septum below the “X” element of the dorsal plate is complete
or nearly complete in Centrochir crocodili, Platydoras costatus, Lithodoras dorsalis,
Anadoras weddelii and grypus and in the adult of Pseudodoras niger.
The septum is not complete in Pterodoras granulosus, Astrodoras asterifrons,
Acanthodoras spinosissimus, Amblydoras hancocki, Doras carinatus, D. punctatus,
Opsodoras humeralis, Leptodoras linnelli and Trachydoras paraguayensis.

292
A REVIEW OF THE DORADIDÆ.
Judging from the miscellaneous species in which it is complete or nearly complete,
and those in which it is incomplete, this character cannot be given much weight in
classification.
D.SI
D.SI
D.SI
ъ
o
2
tripus
A
B
D.S.
D.SI
o
C
mp
INTI
B
D
F
6
KS
22
mp2
f
YI
f
UNTII
G
E
Fig. 9. A, Dorsal lock in Platydoras costatus from the side. B, The same three-quarter view. C, The same from the
top. D and E, Dorsal erect and depressed in Doras micropæus. F and G, Dorsal depressed and erect in Megalodoras irwini.
b, articular surface of the first dorsal spine; D. S. I, first dorsal spine; D. S. II, second or main dorsal spine; E, first dorsal spine;
ſ, lateral flange of the I and II interneurals; K, articular surface of the lateral flange of the second interneural; 1, lateral articular
surface of the dorsal spine; mpl, middle plate of the interneural; o, first dorsal spine.
Surface plates.—Immediately above the humeral process the air-bladder is in
contact with the skin to form a tympanum. The air-bladder space is separated
internally from the muscled region above, either by a membranous septum or by a
bony process or plate (9a in Plates XVIII, XX and XXIV) from the epiotic to a
downward-directed process of the last element of the dorsal plate and the first rib.
The series of lateral scutes consist of one to three small bones without hooks
near the middle of the tympanum, and from 16 to 40 hooked bones along the sides.
The first one to three hookbearing scutes are in contact with the dorsal plate above

A REVIEW OF THE DORADIDÆ.
293
and may or may not reach the humeral process. The last plate is on the middle of
the base of the caudal. The plates are sometimes minute, isolated and imbedded
in the skin (Hassar, Plate XXII; Doras, Plate XXVII, Fig. 4). Sometimes the plates
are very wide, nearly covering the entire sides, Platydoras (Plate IX), Megalodoras
Fig. 10. The humeral region of a specimen of Pseudodoras niger from La Merced, showing the supplementary lateral
scute at X.
(Plate VI), and Acanthodoras (Plate XI). In the extreme the plates of opposite
sides may meet along the middle of the back (Acanthodoras spinosissimus, Fig. 2,
Plate XI).
Rarely, plates are developed along the middle of the back between the dorsal
and the adipose (Lithodoras dorsalis, Hemidoras hemipeltis and morrisi). In one
species, Hypodoras forficulatus, a large regular plate covers the anterior half of the
adipose (Plate IV, Fig. 1, and Plate XXV).
In an extreme case, Lithodoras dorsalis, dermal plates may develop at any point
on the surface and, in very old, they may form a protective armor over the entire
body.
The caudal fulcra are always well developed, frequently they are laminate,
extending forward on the caudal peduncle. Sometimes the fulcra become spread
out forward, forming isolated plates, or plates in contact over the entire region to
the adipose and anal (Plate III, Figs. 1, 5, and 6; Plate IV, various figures).
Air-bladder.—(Plate I.) The greatest amount of variation is found in the air-
bladder. It is indeed difficult to reconcile the fact that the various types of air-

294
A REVIEW OF THE DORADIDÆ.
bladders belong to related species. There are five general types. Of these there
are various modifications and combinations only generally correlated with other
structures.
The simplest, most primitive type is found in Centrochir crocodili, Hoplodoras
uranoscopus and Franciscodoras marmoratus (A, B, C, Text-fig. 12). In these species
the air-bladder, externally at least, is a simple subconical or subglobular bag.
tran.part
tr.part
div.
F
-lon.part
USSMO
B.
NU
-dio.
၁ ၁ )
၁ ၁ ၁၁
tond.
دی در
•P.
div.
tr. part
المدلل
div.
دل لی
lon.port
• lon. part.
UU
D
C
A
E
Fig. 11. Air-bladders of: A, Doras carinatus, the upper wall cut away to show the median partition in the posterior
half and the partial anterior partition at its anterior end. B, Doras carinatus, transverse section, on the left immediately behind
the transverse partition on the right some distance further back. Compare with Plate I, Figs. 22 and 31. C, Pterodoras granu-
losus, dorsal view. Compare with Plate I, Fig. 3. D, The same with the ventral wall cut away to show the partitions and the
tendinous stays on the inner face of the dorsal wall. Compare with Plate I, Fig. 1. E, Doras humeralis, dorsal view, with many
slender diverticulæ. F, Megalodoras irwini, ventral view of the young, 90 mm. long. For the adult see Plate I, Fig. 5. div.,
diverticula; i., pocket for the process of the vertebra; lon. part., longitudinal partition; tend., tendinous stays; tr. part., transverse
partition; p., ventral pockets.
Internally the cavity of the bladder is partially divided into three sections. A
median partition divides the posterior two thirds or three fourths into a right and
left half. In front of this a partition runs partly across the bladder. A horizontal
section of these partitions gives the letter “T.” In front of this “T” the bladder is
a cavity extending from side to side. Into this anterior cavity project the disks and
prolongations of the parapophyses of the fourth vertebra connected with the Weberian
apparatus. The anterior cavity of the bladder is continuous with the posterior
sections along the outer wall of the bladder (Text-fig. 12 and Plate I).
Another simple type occurs in Platydoras costatus (Figs. 14–18, Plate I). In these
species there are two simple bladders connected with each other by a very short,
thin canal. The anterior bladder resembles that of Centrochir, the posterior (cæcum)
is similar but much smaller, elongate, egg-shaped.
The third type is a modification of the second. The posterior bladder is double
or split lengthwise, the two halves sometimes recurved (Text-fig. 12, E et al.).

A REVIEW OF THE DORADIDÆ.
295
а
A fourth type was observed once. This consists of the double air-bladder,
with a third division behind the second in Scorpiodoras heckeli (Text-fig. 12, D).
The fifth type of bladder is provided with a number of radiating tubes or cæca.
The walls of this type are firm, not flexible, provided with internal ridges varying
greatly in number and size. In Pterodoras they are not unlike the ribs of a boat
(Text-fig. 11, Plate I, Figs. 1–3).
The tubes vary greatly in number, number of rows, in size and in character.
Some are simple, narrow, sausage-shaped diverticula around the sides of the bladder.
Others are branched simply or in an arborescent fashion, or even feather or plume
like, and imbedded in masses of fat (Figs. 1 to 4 and 6, Plate I).
C
G
H
F
А
B
D
с
E
6
Fig. 12. Air-bladders of: A, Centrochir crocodili (Humboldt); B, Franciscodoras marmoratus (Reinhardt); C, Hoplodaros
uranoscopus (Eigenmann and Eigenmann); D, Sorpiodoras heckeli (Kner); E, Doras punctatus (Kner); F, Astrodoras asterifrons
(Heckel); G, Acanthodoras spinosissimus (Eigenmann and Eigenmann); H, Leptodoras linnelli (Eigenmann); 1, Hypodoras
forficulatus (Eigenmann).
The beginning of the development of coca in the double air-bladder occurs in
Pseudodoras niger (16, Plate I). In this species the air-bladder has circular, thin
places in the side wall of the depressed bladder. It would seem that the thin walls
of these disks are capable of acting bellows-like with fluctuating pressure. The walls
themselves seem inflexible. The height of modification of this type is found in
Megalodoras irwini (4, Plate I) in which the number, size and elaborateness of the
branching of the diverticula reaches the truly marvelous.
The diverticula in the single air-bladder go through a similar, though not identical,
gamut of development. There may be many very thin tubules in various of the
species with fimbriated maxillary barbels or there may be a few larger, short out-
pocketings as in Leptodoras linnelli. The height of elaborateness is found in Pterodoras
granulosus (1 to 3, Plate I) and is described under that species and in species of
Opsodoras (especially in 0. humeralis (6, Plate I)).
20

296
A REVIEW OF THE DORADIDÆ.
The modifications in the second air-bladder are preserved step-wise in various
species. In its simplest form it is a minute protuberance, Doras carinatus (Fig. 8,
Plate I), next an elongate, ovate bladder with pointed end, with or without diverticula.
The beginning of the double posterior air-bladder is preserved in Lithodoras dorsalis.
In this species an external constriction partially divides the bladder. The end is
divided into two lateral horns. An internal septum completely divides the rest of
the posterior bladder into two unequal lateral parts.
The modifications of this type can best be described by a series of figures of
bladders actually observed.
COMA
B
C
A
NA
E
D
Fig. 13. Lower surfaces of the heads of different species under different magnification. The lines at the margin equal
one inch unless otherwise indicated. A, Rhinodoras d'orbignyi; B, Trachydoras paraguayensis; C. Trachydoras atripes; D, Hassar
wilderi; E, Opsodoras humeralis; F, Hemidoras morrisi.
Barbels.—The barbels are but moderately developed; there is always one maxil-
lary and two pairs of mental barbels. In no species do the maxillaries extend any
great distance beyond the tip of the humeral process. Usually they are shorter.
In many species the mental barbels are warty, or carry supplementary barbels. In
these the bases of the mental barbels, which are in a series close behind the lip (not

A REVIEW OF THE DORADIDÆ. .
297
-
a
а
paired), are frequently united by a broad basal membrane. The height of the compli-
cation in the barbels is found in Leptodoras linnelli (Fig. 2, Plate XXIV). In this
species the maxillary barbel is divided beyond the bone into an inner and an outer
branch.
In the species with fringed mental barbels in which the bases of the barbels are
united by a membrane, the mental barbels can be bent forward to form a screen,
or sieve over the mouth.
Color scheme.—The underlying scheme of coloration consists of a light band
along the spines and darker bands above and below the light band. The darker
bands are continued to the tips of the caudal lobes. The parallel bands on the caudal
are frequently present when there is no indication of a longitudinal stripe elsewhere
(Figs. 1 and 2, Plate IX; 1, 2 and 5, Plate XI; 1 and 4, Plate XII; 1 and 2, Plate XV).
The lateral stripes are best developed in Platydoras costatus. In a few species (Hassar
and Platydoras) there is a black spot on the dorsal. The most strongly marked
species is Acanthodoras spinosissimus. It is black, with light spots and streaks and
has a banded caudal.
Weberian apparatus.—The Weberian apparatus consists of a long, narrow, oval
bone, scaphium or stapes, fitting over the oval opening, fenestra “a,” into the lymph
spaces of the internal ear. Between it and the tripus, imbedded in tendonous tissue,
lies the curved incus or intercalarium; the tripus or malleus is a flat blade extending
backward from the incus to below the lateral process of the fourth vertebra.
In some species the tripus remains a flat blade to its posterior end, in others it is
folded upon itself from its inner edge; at a greater or lesser distance from its posterior
end it comes in contact with the fourth vertebra by one or two short processes forming
the pivot on which it moves.
A slender, unnamed, rod-shaped bone extends from the anterior, raised, lateral
edge of the fourth vertebra backward and attaches by a fan-shaped tendon to the
tripus. The anterior process of the fourth vertebra arises as a thin, sinuous bone
from the basal half of the neural spine. It extends outward and more or less down-
ward, being notched to arch over the tripus.
At the outer edge it is continued, or attached, to a disk or cone, fitting into an
indentation in the anterior or upper wall of the air-bladder. In contact with the
bone the wall is thin, delicate. If conical the apex of the cone is indented into the
air-bladder (Plate XIX, Fig. 4, 1; XX, Fig. 1, i).
The bones are so delicate, so small and so variable that I am not able to state
positively that these structures are built on this plan in all the species. The small
rod from the tripus to the anterior edge of the fourth vertebra seems to be especially

298
A REVIEW OF THE DORADIDÆ.
variable. The part of the process of the fourth vertebra which is hooked over the
outer edge of the tripus is also variable.
The body of the fourth vertebra is very long, its lower surface smooth and
intimately associated with the air-bladder. Sometimes (in A. spinosissimus) a
deep median septum is developed in the mid-ventral line. The anterior end of the
vertebra is always well marked, sometimes by a thickening or general enlargement,
o
с
b
a-
La
a
с
f-
ed
A
B
D
Fig. 14. The auditory, or Weberian ossicles of Pseudodoras niger. A, The right ossicle seen from below; B, the same
from the vertebral viewpoint; C, the anterior end of A seen from above, more enlarged. The fulcrum, f, situated near the middle
in A and B, is broken and restored in outline in A. D, the ossicles in another individual showing the supplementary bone, d,
attached at the right; a, tripus or malleus, supposed to be the modified rib of the third vertebra; b, intercalarium or incus, sup-
posed to be the modified neural arch of the second vertebra; c, scaphium or stapes, supposed to be the modified neural arch of
the first vertebra. The claustrum, not shown in the photograph, is supposed to be the spine of the first vertebra. More probably
the "scaphium and claustrumº represent the first neural arch and rib.
sometimes by a sharp ridge. The latter is much exaggerated in Leptodoras, in which
it forms a deep pocket divided by a median septum. Into these pockets the anterior
ends of the air-bladder fit.
DISTRIBUTION AND RADIATION OF THE DORADIDÆ.
The species of the Doradidæ belong prevailingly to the lowlands of the Amazons,
ascending in the Chanchamayo to at least 2,500 feet, and in the Urubamba to 3,000
feet.

A REVIEW OF THE DORADIDÆ.
299
6
Anda
VANDO
OUR
100
.
Copiapo
Lantern
का
Porte
Topende
shior
FIG. 15. Distribution of the Doradida. Areas in doubt marked ?.
They extend in a long pseudopodium down the Paraguay to the La Plata. The
number of species that extend into the La Plata-Paraguay basin is but five, of which
two, the genera Oxydoras and Rhinodoras, are peculiar to that system. Two other
species extending into the La Plata system, Pterodoras granulosus and Platydoras
costatus, are the most widely distributed species of the family. The fifth, Trachydoras
paraguayensis, occurs on both sides of the divide separating the Paraguay and the
Amazon. The La Plata is beyond the normal range in climate of the species and

300
A REVIEW OF THE DORADIDÆ.
A
their southward extension is evidently due to the facilities for easy movement fur-
nished by the Paraguay-La Plata river.
At that, no member of the Doradidæ has been recorded from the upper Parana.
Nor do they occur in any of the rivers emptying between the La Plata and the Rio
San Francisco. Their point of origin is evidently the Amazonian basin; all but
Oxydoras, Rhinodoras and Franciscodoras occur in the Amazon basin. The Rio San
Francisco has provided means of migration to points not otherwise accessible and is
responsible for another pseudopodium-like extension of habitat. They are found
throughout the San Francisco but not east of it as far as is known.
One of the species of the San Francisco, Franciscodoras marmoratus, with a simple
air-bladder is peculiar to it. Platydoras costatus and Pseudodoras niger are the other
species of the San Francisco. They are widely distributed species.
I found no members of the Doradidæ above the Kaieteur falls and on the basis
of that fact I have left the highlands of the Guianas blank in the distribution map.
But one species is found west of the Andes, Centrochir crocodili. It is a species
without strongly marked characters; it, like Franciscodoras, has a simple air-bladder.
The Brazilian Amazons are most abundantly supplied with members of the
Doradidæ. Next comes the Marañon. As far as the evidence goes at present, the
species of the genus Doras prevail in the Brazilian Amazons while those of its ally,
Opsodoras, prevail in the Marañon.
As far as the evidence goes, it points to the conclusion that the Doradidæ antedate
the present configuration of the country and that they were in what are now the
Magdalena, San Francisco, and La Plata basins from early times.
They evidently formed part of the fauna segregated by the formation of the
Cordillera of Bogota and have not had access to the Magdalena since these mountains
were formed. Franciscodoras, the peculiar genus of the Rio San Francisco, is evi-
dently the original member inhabiting the Rio San Francisco. Platydoras (and
Pseudodoras?), found everywhere, may be part of the original fauna; but as they are
not found in the Magdalena, they may be later products which have migrated into
the San Francisco by way of the Tocantins, Somo and Rio Preto.
Similarly, the genera peculiar to the La Plata basin, Rhinodoras and Oxydoras,
may be looked upon as the more slightly modified descendants of the original fauna.
Platydoras costatus may also be an original inhabitant but has less claim since it would
involve the supposition that it has retained its character, both in the San Francisco
and the Plata, since early time. It seems clear that Trachydoras paraguayensis,
belonging to an otherwise Amazonian genus and to a species also found in the Amazon
basin, is an interloper in the Paraguay.

A REVIEW OF THE DORADIDÆ301
.
.
Centrochir of Trans-Andes, Franciscodoras peculiar to the San Francisco, Rhino-
doras and Oxydoras peculiar to the La Plata, are of very long-standing and a composite
of these and of their nearest, and at the same time most widely distributed, relatives
probably presents a generalized portrait of the earliest Doradid. See Centrochir
crocodili (Plate VIII); Franciscodoras marmoratus (Plate XXIX); Rhinodoras d'or-
bignyi (Plate XXVI, Fig. 5); Pseudodoras niger (Plate XVII); Platydoras costatus
(Plate IX). To these should probably be added Pterodoras granulosus (Plate VII, a),
generalized Doradid externally but with an incomprehensible air-bladder.
From these generalized species there have been specializations along some definite
lines, the modifications of one character frequently not correlated with modifications
in other characters.
Megalodoras has gone but a short distance. It has emphasized the spines of
the fins. Lithodoras has reached the maximum in the development of the number
of dermal plates, which, however, have also increased in Hypodoras and Hemipeltis.
The size of the lateral scutes has gone both up and down from the normal. They
have reached their minimum, not in number but in general development, in Doras
micropæus and Opsodora hemipeltis. I was inclined to place a higher value on the
reduction in the size of the plates than it merits. The species with reduced plates
are more nearly related to different species with well-developed plates than they are
to each other. The reduction of the plates has taken place independently in different
species. The pairs Doras carinatus to Doras micropæus and Opsodoras parallelus to
hemipeltis are evidently more closely related to each other than the last of each
of these pairs with minute plates is to species of Hassar which have minute
plates.
The upward variation in the size of the plates reached its maximum in Acantho-
doras. In this and the nearest related forms the scutes are variously provided with
spines. The caudal fulcra, well developed in the typical species, have undergone
development in several independent lines. In several independent lines the anterior
ones have become enlarged and cover the caudal peduncle more or less completely.
The modifications of the pectoral musculature, the granulation of the coracoid
and the development of a “diaphragm” have been mentioned above.
The mouth, the dentition, the barbels and the food habits have been associated,
correlated modifications, directed distinctly away from the generalized Centrochir and
Franciscodoras. In a measure each genus and species is the end product of series of
modifications from the generalized Doradid. Among those that have gone furthest
afield are Trachydoras with its associated Hemidoras and Doras, and Leptodoras with
its associated Nemadoras, Hassar and Opsodoras.

302
A REVIEW OF THE DORADIDÆ.
TABLE OF DISTRIBUTION.
The following table indicates the species not seen by the author, the species known from the
types only (marked *), the length in millimeters of the largest recorded specimen and the recorded
distribution of the various species.
Largest Specimen Known.
Bahia to Rio Grande do Sul.
Orinoco and Venezuela.
Rio San Francisco.
Paraguay.
La Plata.
Bolivia.
Guianas.
Magdalena.
X XXX XXX Brazilian Amazon.
X X X Marañon.
Х
XIX
X
Х
x
Х
Х
Х
Х
..X
XX
X
XX
ХХХХ
X X
XX
Х
XX
I. Megalodoras irwini ..
libertatis (not seen)f...
II. Centrodoras brachiatus ...
III. Hoplodoras uranoscopus*
IV. Pterodoras granulosus. .
lentiginosus*.
V. Centrochir crocodili.
VI. Platydoras costatus.
albomaculatus (not seen)*
helicophilus (not seen)*
dentatus (not seen)*. .
VII. Franciscodoras marmoratus.
VIII. Lithodoras dorsalis....
IX. Acanthodoras calderonensis (not seen)
cataphractus. .
spinosissimus.
X. Agamyxis pectinifrons (not seen)*
flavopictus (not seen)*.
XI. Astrodoras asterifrons...
XII. Scorpiodoras heckelii.
XIII. Amblydoras monitor*
hancocki ...
XIV. Anadoras regani (not seen)*
grypus.
nauticus (not seen)*
weddellii .
insculptus*.
XV. Hypodoras forficulatus*
XVI. Physopyxis lyra*.
XVII. Pseudodoras niger.
huberi (not seen)*
XVIII. Oxydoras kneri ..
XIX. Rhinodoras d'orbignyi....
XX. Trachydoras paraguayensis.
nattereri..
atripes..
trachyparya (not seen)*
XXI. Doras fimbriatus (not seen)*
brevis (not seen)*.
punctatus...
612
112
410
530
230 X X X
357
210
217
Х
85
350
135
360
960
103
170
150
76
110
100
173
38
123
90
150
82
113
100
123
35
840
400
360
160 X
Х
93
130?
103
93
125
125
125
Х
•
X X X X X
X X X X X X X X
x
Х
Х
XX
XXX
Х
ХХ ХХХХ
XXX
*

A REVIEW OF THE DORADIDÆ.
303
The Largest Specimen Known.
Bahia to Rio Grande do Sul.
La Plata.
X Paraguay.
Orinoco and Venezuela.
Rio San Francisco.
Brazilian Amazon.
Bolivia.
Marañon.
Guianas.
Magdalena.
Х
.
XXX XX
XXX
?
ХХХХХХ
Х
Х
Х
XXII. Dor as eigenmanni .
microstomus.
carinatus...
micropæus*
lipophthalmus (not seen)*..
XXIII. Hemidoras stenopeltis.
morrisi...
XXIV. Opsodoras hemipeltis*
parallelus*.
humeralis..
orthacanthus*
trimaculatus.
leporhinus..
ternetzi ..
boulengeri (not seen)*
stübeli (not seen)*
morei (not seen)*...
steindachneri (not seen)*
XXV. Hassar affinis (not seen)* †
orestis
wilderi*
notospilus*
XXVI. Leptodoras linnelli .
acipenserinus.
juruensis (not seen)*
hasemani (not seen
XXVII. Nemadoras elongatus (not seen)*
bachi (not seen)*.
95
52
267
270
190
160
147
143
151
154
133
77
81
129
167
120
125
235
255
196
215
70
209
223
235
132
105
90
ХХХХ
Х
XX
XX
.
ХХ ХХХХХХ
Х
2
5
5
3 47 26 15
2
1
TOTALS..
58
† Paranahyba and Itapicuru.
Along one line, the dorsal spine, originally serrate, has become less and less
serrate till it has lost all serration in Astrodoras. The preorbital, procumbent and
smooth in the original Doradid has become serrate and pectinate, the marginal
teeth becoming erect, a line of development reaching its maximum in Agamyxis and
Astrodoras.
Along another series the eye has become reduced in size, a modification indicated
by peculiar adjustments in the orbital bones.
Conclusion.—Members of the Doradidæ are found from Buenos Aires through
the Paraguay, Madeira, the Amazons to the Guianas and from the mouth of the Rio

304
A REVIEW OF THE DORADIDÆ.
San Francisco and Para to an elevation of about three thousand feet at the base of
the Andes in Bolivia and Peru. One member of the family, Centrochir longispinis,
is found in the Magdalena river, across the first chain of the Cordilleras in Colombia.
As far as is known, they do not occur in the rivers between the mouth of the Rio San
Francisco and the Rio Plata or in the upper courses of the Rio Parana.
KEY TO THE GENERA OF THE DORADIDE.
a. Head depressed; width at the clavicle greater than the length of the head to the end of the bony opercle;
eye, if small, far in front of the middle of the head; if large or medium, near middle of the head; mouth
terminal, wide; premaxillary wide, fixed, with a band of teeth; epiotic bordered by the occipital, two
nuchal plates, the supraclavicle and pterotic; process of epiotic not reaching the first rib and first hook-
bearing lateral scute, except in Pterodoras; barbels all simple.
6. Adipose fin continued forward as a low keel, longer than anal fin; snout smooth, preorbital bones not
pectinate or serrate; caudal forked.
c. Caudal peduncle naked above and below, or the posterior half covered with laminate caudal
fulcra.
d. A second air-bladder or cæcum; both depressed and fringed with numerous diverticula (not
examined in libertatis.
*. Less than 23 lateral scutes; fewer thorns on posterior face of the dorsal spine than on
the anterior.....
1. Megalodoras Eigenmann, gen. nov.
** Scutes about 38-40 on a side.
2. Centrodoras Eigenmann, gen. nov.
dd. Only one air-bladder.
e. Lateral scutes 18; air-bladder wider than long, with a marginal row of long, diverticula;
thorns on back of dorsal spines fewer and smaller than on anterior margin.
3. Hoplodoras Eigenmann, gen. nov.
ee. Lateral scutes 25 to 30, very narrow, strongest over end of anal; eye entirely in the front
half of the head; about 20 thorns on the posterior face of the dorsal spine, nearly of
equal size with those covering the opposite side or anterior face; no posterior air-bladder,
the anterior depressed, margined with fimbriated diverticula on the posterior and lateral
edge, a long plume-like diverticulum on the outer anterior angle, curved around to the
front; a bony stay behind the tympanum.
4. Pterodoras Bleeker.
eee. Lateral scutes 30. Fontanel not constricted; skull finely granular, arched; posterior
hooks of the dorsal spine stronger than the anterior; three hook-bearing scutes in contact
with the dorsal plate, the rest of the scutes graduate to the last, narrow; depth of the
air-bladder more than half its width, without diverticula, no second air-bladder or
cæcum. (See also bb.).
(See also bb.). .....
......5. Centrochir Agassiz.
cc. Caudal peduncle entirely covered with plates above and below (modified fulcra); scutes very deep,
leaving only a narrow naked area along the back; three scutes in contact with the dorsal plate;
posterior thorns of the dorsal spine disappearing with age; eye in middle of the head; air-
bladders without diverticula, large; depth of the anterior air-bladder half its width; posterior
carrot-shaped....
.6. Platydoras Bleeker.
bb. Adipose fin high, longer than anal, not continued forward as a keel, or continued for a short distance
only; dorsal spine serrate in front only; eye nearer snout than to end of opercle; caudal peduncle
largely covered with fulcra above and below, increasing in size forward. Scutes about 30, about

A REVIEW OF THE DORADIDÆ.
305
one third or a little less of the depth; caudal forked or deeply emarginate; fontanel without groove,
its depression ending abruptly; anterior air-bladder large, divided by a median partition to very
near the anterior end, without diverticula; no posterior bladder or cæcum.
7. Franciscodoras Eigenmann, gen. nov.
bbb. Adipose fin shorter than anal, not shading into a keel in front (A. calderonensis?).
f. Dorsal spine serrate in front and behind, the posterior serræ stronger than the anterior; lateral
scutes 16 to 20; caudal forked..
8. Lithodoras Bleeker.
ff. Dorsal spine serrate in front, not behind; caudal round or truncate.
g. Caudal peduncle without plates above and below; nasal bone short, with less than ten spines;
eye minute, about 4 in interorbital, far in advance of the middle of the head; fontanel sub-
circular; breast entirely covered with skin or the tips of the coracoid process granular; sides
of dorsal spine and upper surface of the pectoral spine serrate, except in A. calderonensis.
Caudal round or truncate. (Species with light stripe along the sides.)
9. Acanthodoras Bleeker.
gg. Caudal peduncle with spiny plates above and below; sides of the dorsal and pectoral spines
serrate; nasal plate erect, pectinate; eye moderate, in advance of the middle of the head;
dorsal and pectoral spines with spines along the side. (Species without a light line along
the spines.)......
....10. Agamyxis Cope.
ggg. Caudal peduncle with prominent laminate caudal fulcra covering about half its surface above
and below; dorsal and pectoral spines with ridges on the sides.
h. Nasal plate erect; width at clavicle greater than distance from snout to end of dorsal plate;
posterior air-bladder simple or forked. ...
11. Astrodoras Bleeker.
hh. Nasal plate procumbent; width at clavicle about 1.25 in distance between snout and end
of dorsal plate; second air-bladder heart-shaped, with a simple cæcum.
12. Scorpiodoras Eigenmann, gen. nov.
fff. Dorsal spine grooved, without spines on sides, front, or back, except in Physopyxis.
i. Adipose fin present; coracoid process shorter than humeral process.
j. No plates between dorsal and adipose; caudal truncate.
k. Granulations of coracoid and clavicle confluent into a large buckler; nasal serrate.
13. Amblydoras Bleeker.
kk. Granulations of coracoid and clavicle not confluent, a space covered with skin between
the granulations; nasal not serrate..
14. Anadoras Eigenmann, gen. nov.
jj. A large plate over anterior part of adipose; caudal truncate; nasal serrate.
15. Hypodoras Eigenmann, gen. nov.
ii. No adipose; coracoid processes lyre-shaped, reaching ventrals, much larger than humeral
processes which do not reach the first lateral scute; caudal rounded.
16. Physopyxis Cope.
aa. Width at the clavicle less than the length of the head; snout conical or subconical; mouth relatively
small; premaxillaries attached to the front of the maxillary, not joined to each other, not joined to the
ethmoid, which is pointed and without lateral wings in front. Teeth feeble or none. Caudal forked.
1. Nuchal shields without a foramen.
m. Barbels simple. Mental barbels not united by a membrane joining their bases. Adipose fin
continued forward as a low keel, longer than anal fin; epiotic bordered as under a of the
Key, not joined by process with the first hook-bearing scute; first nostril remote from the
lip.

306
A A REVIEW OF THE DORADIDÆ.
n. Eye behind middle of head; caudal peduncle naked above and below. Serræ on posterior
margin of the dorsal spine antrorse, or at right angles to the spine, less numerous and much
more feeble than those of the anterior margin; fontanel with a bridge.
0. Lateral scutes 16–23; rows of tentacles on roof of mouth.... ....17. Pseudodoras Bleeker.
00. Scutes 34-40; no tentacles on roof of mouth..
18. Oxydoras Kner.
nn. Eye in middle of head; caudal peduncle entirely covered above with laminated caudal fulcra,
nearly entirely covered below; serræ on posterior face of dorsal spine retrorse, much longer
than those on anterior; fontanel not divided; lateral scutes about 30.
19. Rhinodoras Bleeker.
mm. Maxillary barbels fringed, the bases of the mental barbels united by a membrane; eye behind
the middle of the head; dorsal serrate on both margins; caudal forked; adipose short; epiotic
forming part of the edge of the skull between the supraclavicle and the nuchal plate, with a
process to the first hook-bearing scute; second air-bladder minute or absent.
p. Opercle, preopercle and coracoid-process granular; first lateral scute large; fontanel not con-
tinued as a groove; adipose not continued as a ridge.
20. Trachydoras Eigenmann, gen. nov.
pp. Opercle, preopercle and coracoid process covered with skin. Back and ventral surface without
plates. Adipose not continued as a ridge....
.21. Doras Lacépède.
Il. Nuchal shields with a foramen on each side.
q. Maxillary barbel fringed with minute barbels, otherwise as under ll.
r. A series of plates between the dorsal and adipose and sometimes between the ventrals and
22. Hemidoras Bleeker.
rr. Back without scutes.
s. Origin of ventrals nearer caudal than to snout; adipose not continued forward as a ridge.
t. Eye normal; scutes usually well developed........23. Opsodoras Eigenmann, gen. nov.
tt. Eye elongate; snout very long and slender; humeral process large and rounded.
24. Hassar Eigenmann and Eigenmann.
ss. Slender, origin of ventrals nearer snout than to caudal; air-bladder very short, fitted into
cupped downward processes of the coalesced vertebræ; adipose continued forward as
a keel....
.25. Leptodoras Boulenger.
99. Maxillary barbels simple; mental barbels connected by a basal membrane; adipose short.
26. Nemadoras Eigenmann, gen. nov.
anal....
Genus I. MEGALODORAS Eigenmann, gen. nov.
Type, Megalodoras irwini Eigenmann.
Lateral plates few; adipose fin continued forward as a keel; head depressed,
snout not conical; serræ of posterior margin of dorsal spine fewer and weaker than
the anterior, obsolete with age; eye in middle or near middle of the head; suborbital
chain (Fig. 4, Plate 6) consisting of three bones, the anterior in contact with the
lower surface of the preorbital; the second borders about half the eye, is much wider
than the posterior and has small spines at the upper border, its anterior end in contact
with the first and with the preorbital; preorbital large, granular along its upper margin,
in contact with the premaxillary and maxillary in front; mouth subterminal; occipital
region somewhat roof-shaped, with or without median groove.

A REVIEW OF THE DORADIDÆ.
307
Air-bladder (of Megalodoras irwini, Fig. 4, Plate I and Text-fig. 12) much de-
pressed, in two parts. The anterior part heart-shaped, nearly as wide as long, with
about a dozen tubular cæca or diverticula in a row from the outer posterior angle
around the sides to near the center in front; the coca largest behind, smallest in front,
all of them profusely branched; a few much smaller coca in a row behind the outer
row in front; the posterior bladder as long as the anterior, a constriction between the
two; much narrower than the anterior and tapering backward. About seven lateral
diverticula along the sides of the second bladder, decreasing in size backward and
branched like the posterior ones of the anterior bladder. The chief features of the
bladder are developed in a specimen 90 mm. long; but the posterior bladder shorter.
The air-bladder has not been examined in libertatis.
KEY TO THE SPECIES OF MEGALODORAS.
a. Lateral scutes, 17 or 18.
b. Eye 2.5 to 3 in the interorbital.
c. Fontanel narrow, not continued as a groove; dorsal spine smooth behind; scutes 2 + 17; fins
spotted; lower half of sides mottled and spotted. 700 mm. over all.....1. irwini Eigenmann.
cc. Fontanel continued to the middle of the occipital as a wide shallow groove, to the end of the
dorsal plate as a narrow groove; eye nearly 3 in the interorbital; scutes 15 to 17. Gill-opening
extending to middle of the pectoral spine; dorsal spine with few serræ behind.
2. irwini Eigenmann, spec. nov.
bb. Eye 1.6 in the interorbital; scutes 18; dorsal spine strongly serrate on both margins. Fontanel
continued to the end of the dorsal plate...
.3. libertatis Ribeiro.
1. Megalodoras irwini Eigenmann.
Plate 25, Fig. 1.
T. R. S. No. 2567; type, skin; Kartabo, Bartica District, British Guiana, September 11, 1919; William Beebe.
Measurements in life: length, 612 mm.; length entire, 700 mm.; width, 170 mm.;
depth, 110 mm.; head, 140 mm.; interorbital, 48 mm.; weight, 9 pounds; D. I, 6;
A. 12,; scutes 2 + 17; width of head equal to its length; eye 3.5 in snout, 6.5 in head,
2.6 in interorbital; dorsal spine 110 mm. long, striate on the sides, smooth behind,
with about 40 serræ on the anterior margin, increasing slightly toward the tip; pectoral
spine 155 mm. long, striate on the sides with about 50 serræ on the anterior margin,
38 on posterior; humeral process narrow, two thirds as long as pectoral spine; fontanel
a narrow slit, ending abruptly over middle of eye, not continued as a groove, not
constricted; two angular plates in the tympanum, in a line with the spines of the
plates; the third to ninth plates highest, a little more than snout and eye, the hooks
increasing in size to above the anal. The following is taken from the field notes:
Ground color pinkish buff, becoming clear cream buff on the under side of the head.
Top of the head indistinctly mottled with black. Side plates, ventral, anal and caudal

308
A REVIEW OF THE DORADIDÆ.
fins irregularly mottled or spotted with black. Pectoral fins almost entirely black,
pinkish buff at base. Interplate space of the back black, as is also the skin just back
of the side of the top of the head, and anterior to the large side plates. Belly in-
distinctly mottled with black, the mottling more concentrated at the sides.
The stomach of this fish was entirely empty, while the intestine had seven
specimens of the common large brown river snail, evenly spaced along its length.
The Creole name of this fish is “Key-way-mamma,” which translated means
"mother of the snails," in allusion to its habit of feeding upon snails. The fish are
not eaten by the natives, their flesh being too tough and not considered wholesome.
This specimen was captured upon a hook.
This large specimen was originally given a distinct name. No. 16168 intermedi-
ate in size, 395 mm., shows the Guiana specimen to be but an over-large specimen of
M. irwini and the name proposed for it has therefore been suppressed.
2. Megalodoras irwini Eigenmann, spec. nov.
Plate 1, Fig. 4; Plate 3, Fig. 3; Plate 6, Figs. 1-4; Plate 25, Fig. 2;
Text-fig. 11, F.
I. U. M. 15427, 5, 90, 220, 278, 300 and 315 mm. The 278 mm. specimen, the type. Iquitos, Allen 1920
and Morris 1922.
I. U. M. 16168, 2, 275 and 395 mm. Santarem market, 1924. Carl Ternetz.
Head 4; depth 4-4.5; D. I, 6; A. 12 or 13; scutes 2 + 15 to 17; width of head
equal to its length; interorbital 2.75–3; eye equidistant from snout and end of opercle;
its diameter 8 in the head, 3 in the interorbital; width of mouth about equal to the
interorbital; teeth minute but firm, in well-developed narrow bands; snout depressed;
profile along median line to occipital straight; fontanel continued as a groove to the
dorsal; opercle, suborbital, and nasal granular; head granular to near the anterior
nostrils; maxillary barbels in the three larger extending beyond tip of humeral process;
outer mental barbels reaching beyond base of pectoral spine or entire base of pectoral
fin, the inner mental barbel about half as far; dorsal spine about two-thirds as long
as the pectoral spine, about equal to the length of the head less half the opercle, its
sides striate, serrate in front (32 to 35) and behind (22 to 25); pectoral spine very
strong, considerably longer than the head, its upper and lower surfaces striate, its
anterior and posterior edges very strongly serrate; humeral process very rough,
reaching to or beyond the middle of the pectoral spine; two small free plates above
the humeral process, in a line with the first four hooks; the first lateral plate in contact
with the dorsal plate and humeral process; the anterior lateral plates crowded, those
over the anal wide, the spines increasing in size to those above the anal; surfaces of
the plates above the ventrals spinulose, the spinules decreasing in number to the
a

A REVIEW OF THE DORADIDÆ.
309
caudal peduncle, the plates on the caudal without spinules, but with a prominent
median spine; a hard keel forward from the adipose; many caudal fulcra, but no
plates on caudal peduncle above or below. Skin of back and sides with hard papillæ;
a narrow light band from the dorsal to the tip of the upper caudal lobe, a wavy light
band from above the eye, following the edge of the skull then back along the upper
half of the lateral plates; a similar band on the humeral process and back on the lower
half of the plates, the two lateral bands, irregular, with interruptions and unions;
lower surface with spots decreasing in size to the middle of the belly; fins spotted,
the pectoral dark anteriorly.
3. Megalodoras libertatis (Ribeiro).
Plate VII.
Doras libertatis Ribeiro, Comm. Linhas. Telegr. Estrat. Matto Grosso as Amazonas Annexo 5, 1912, p. 20
(Manaos).
Scutes 18; head 4, depressed forward, mouth equal to distance between the
outer borders of the nasal crests; maxillary barbel beyond basal third of pectoral;
anterior nares on lips; groove of fontanel to end of occipital process; low, radiating
ridges from center of scutes to the margin of the scutes where they end in a spiny
tubercle; dorsal spine reaching the 10th scute; adipose small, over posterior part of
the anal; two rows of contiguous spots from the snout to the base of the upper caudal
lobe; a more or less interrupted band from the snout, through eyes, along the spines to
the caudal; another series, less distinct, from the angle of the mouth to the ventrals;
spots on the belly. After Ribeiro. This species is known from the type only. 112
mm. long in the museum at Rio de Janeiro.
Genus II. CENTRODORAS Eigenmann, gen. nov.
Type, Doras brachiatus Cope.
Eye in middle of head; fontanel not constricted, not continued as a groove; three
scutes in contact with the dorsal plate, rapidly graduate to about the 6th, then narrow;
dorsal spine with antrorse hooks in front, with straight to retrorse hooks behind;
bones of the head striate. Width a trifle more than head; plates very numerous, 38–
40; air-bladder cardiform, depressed, with numerous, fimbriated or tufted diverticula;
a narrower second bladder or cæcum with very profusely tufted lateral diverticula
which are brittle.
a

310
A REVIEW OF THE DORADIDÆ.
Fig. 16. Air bladder of Centrodoras brachiatus (Cope). Left from above, right from below.
4. Centrodoras brachiatus (Cope).
Doras brachiatus Cope, Proc. Acad. Sci. Phila., 1871, p. 270 (somewhere between mouth of Rio Negro and
the Huallaga); Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 234; Ribeiro,
Peixes, IV, 1911, p. 216.
Rhinodoras amazonum Steindachner, Sb. Ak. Wiss. Wien, LXXI, 1875, p. 141, Pl. II, 1875 (Amazon near
Teffé); Ribeiro, Peixes, IV, 1911, p. 197, Fig. 94.
Oxydoras amazonum Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 159; Fisher, Ann.
Carnegie Mus., XI, 1917, p. 421 (between Santarem and Pará).
Known from the types of C. amazonum and C. brachiatus the specimen recorded.
by Fisher and 16166 and 16167, 367 and 410 mm. Santarem market. Carl Ternetz.
Genus III. HOPLODORAS Eigenmann, gen. nov.
Type, Doras uranoscopus Eigenmann and Eigenmann.
This genus is very similar to Megalodoras in all outer appearances, but the air-
bladder differs. The air-bladder is single, wider than long and with a single series of
simple cæca or diverticula. As in Megalodoras the adipose fin is prolonged forward as
a keel and the lateral scutes are large, few in number.

A REVIEW OF THE DORADIDÆ.
311
5. Haplodoras uranoscopus (Eigenmann and Eigenmann).
Plate 12, Figs. 1 and 2, Text-fig. 12C.
Doras uranoscopus E. & E., Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 159; Occasional Papers Cal. Acad. Sci.,
I, 1890, p. 228.
Known from the type in the Mus. Comp. Zoöl.; a specimen 530 mm. long from
Lake Hyanuary
Caudal fulcra laminate, the first a plate.
Snout 57 mm.; eye 19 mm.; postorbital part of head 50 mm.; distance from
snout to dorsal fulcrum 185 mm.; length of dorsal 49 mm.; distance from end of dorsal
to end of adipose 136; distance from adipose to end of caudal lobe 160 mm.
No groove on dorsal plate; a groove from the fontanel to the dorsal plate, in-
terrupted at base of occipital process.
Head greatly depressed, the eyes directed upward more than sideways; fins with
many small spots; scutes 18; dorsal spine serrate in front, with a few hooks on its
posterior margin; gill-opening extending to a point midway between upper angle of
gill-opening and eye.
Genus IV. PTERODORAS Bleeker.
a
Pterodoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, pp. 16 and 86.
Type, Doras granulosus Valenciennes.
Eye small, far in advance of middle of the head; palatine bone very small; the
first suborbital rudimentary, the second small, attached for its entire length along
the lower surface of the thick preorbital; preorbital in contact with the premaxillary
and maxillary; adipose fin prolonged forward as a keel; dorsal spine strongly serrate
on both margins; lateral scutes low, 22 + 29, directly continuous (in line) with those
on the pseudotympanum; caudal forked; caudal peduncle naked above and below;
head depressed, snout broad; fontanel continued as a groove to the tip of the occipital
process.
No posterior air-bladder (5 and 6, Plate 7); anterior air-bladder heart-shaped,
7
with a wide fringe of tubules along the sides; a plume-like diverticulum with a double
series of tubules from the anterior outer angle and curving around the anterior end,
the tips of the two feather-like structures meeting near the middle in front; 3 or 4
series of short wart-like prolongations on the upper surface between the lateral
diverticula, gradually reduced to a single series on the side; a bony stay or septum
from the temporal plate to the process of the dorsal plate (9a, Figs. 3, 4, 5, Plate 7),
separating the musculature above from the cavity in which the air-bladder lies.
21

312
.
A A REVIEW OF THE DORADIDÆ.
Very similar to Megalodoras, differing in having narrower, more numerous lateral
scutes, a very different air-bladder, and a bony stay from the epiotic, behind the
tympanum (toward vertebræ). This is the only genus with simple barbels having
a bony stay connecting the epiotic with the first spine-bearing scute.
6. Pterodoras granulosus (Valenciennes).
Plate 1, Figs. 1-3; Plate 3, Fig. 6; Plate 8, Figs. 1-5. Text-fig. 17.
Doras granulosus Valenciennes, in Humboldt, Rec. d'Observ. de Zool. et d’Anat. Comp., II, 1811, p. 184;
Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 229 (Arary?, Uruguay;
Buenos Ayres; Serpa); Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, p. 392; Mem.
Carnegie Mus., V, 1912, p. 185; Fisher, Ann. Carnegie Mus., XI, 1917, p. 419 (Santarem; Rio
Mamoré).
Pterodoras granulosus Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 15 (name only); Silures de Suriname, 1864,
p. 36 (Surinam).
Doras maculatus Valenciennes, in d’Orbigny, Voy. Am. Mer., V, II, 1847, p. 7, Pl. 5, Fig. 3; Cuvier and
Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 281 (Buenos Ayres); Müller and Troschel, in Schomburgk,
Reisen, III, 1848, p. 629; Steindachner, Denkschr. Akad. Wiss. Wien, XLI, 1879, p. 47 (Rio de la
Plata); Eigenmann and Eigenmann, Proc. Cal. Acad. Sci. (2), I, 1888, p. 150 (Arary?); Occasional
Papers Cal. Acad. Sci., I, 1890, p. 229 (Arary?; Uruguay; Buenos Ayres; Serpa); Ribeiro, Peixes, IV,
1911, p. 214.
Doras murica (ex Natterer, MS.) Kner, Sb. Akad. Wiss. Wien, XVII, 1885, p. 129 (Cujaba).
Doras muricus Günther, Catalogue, V, 1864, p. 202 (Demerara?).
Specimens Examined.
9836, I. U. M. 1, 127 mm. Asuncion, Paraguay. J. D. Anisits.
16175, I. U. M. 3, 213 to 231 mm. Belem (Pará) Fish market. Carl Ternetz. May 1924.
15659, I. U. M. 2, 95-117 mm. Marañon below Pastaza. Allen. Oct. 1920.
15846, I. U. M. 2, 203-216 mm. R. Ucayali, Contamana. Allen. July 1920.
15847, I. U. M. 14, 87–182 mm. Iquitos. Allen. Sept. 1920.
15848, I. U. M. 4, 150-200 mm. R. Puinahua, mouth of R. Pacaya. Allen. Sept. 1920.
Head 4 to 4.33; D. I, 6; A. 13; scutes 1 or 2 + 23 to 28; width at clavicle a little
over 3 in the length; eye 7 in the head, 2.1 in the snout, 3 in interorbital in the young,
respectively 10, 7.5, 4.5 in the old; distance between the nasal openings from each
other at least twice as great as the anterior from the lip; mouth terminal, broad,
the upper jaw a little the longer, teeth moderate; gill-rakers minute; maxillary barbel
reaching about to tip of humeral process.
Profusely spotted.
The suborbital ring of this species points to an ancestry with a much larger eye
than the present.
It is very desirable that the air-bladder of specimens from La Plata be examined.
a

A REVIEW OF THE DORADIDÆ.
313
7. Pterodoras lentiginosus (Eigenmann).
Text-figs. 17 and 18.
Doras lentiginosus Eigenmann, Ann. Carnegie Mus., XI, p. 401, 2 figures, 1917. (Santarem; Manaos.)
7049, C. M. paratype, 250 mm. Haseman.
This species is known from two specimens in the Carnegie Museum. It differs
but slightly if at all from granulosus, the head being slightly longer.
<333
FIG. 17. Pterodoras lentiginosus (Eigenmann). From the type in the Carnegie Museum. Kennedy, del.
Genus V. CENTROCHIR Agassiz.
Centrochir Agassiz, Gen. et Spec. Pisc. Bras., 1829, p. 14.
Type, Doras crocodili Humboldt.
Width at clavicle more than length of head; lateral plates numerous, the first
two or three in contact with the dorsal plate, graduate to the last, each with a simple,
central hook; adipose fin continued forward as a keel; head not depressed, arched
behind the fontanel, the bones finely granular; snout depressed, conical, mouth
narrow, terminal; teeth well developed, in bands; serration on posterior margin of
the dorsal stronger than that on anterior; fontanel continued or not continued as a
groove; eyes moderate, lateral, in center or a little behind center of head; anterior
nostril near the lip; caudal forked; preorbital overlying and in contact with the pala-
tine, not reaching the maxillary and premaxillary in front, its free margin feebly but

314
A REVIEW OF THE DORADIDÆ.
regularly notched; first suborbital under the preorbital, the second and third of about
equal width, entirely in orbital border.
The air-bladder deep, heart-shaped, without diverticula, no second air-bladder
(4, Plate 8; 14, Plate 2).
A.
С
stan
B
D
Fig. 18. Air bladders of Pterodoras. A, lentiginosus, dorsal view. B, lentiginosus, ventral view. C, granulosus, dorsal view.
D, granulosus, ventral view.
Except on the obvious external characters this description is based on C. crocodili.
In the absence of the second air-bladder this genus differs from its nearest
relatives.
Habitat: Magdalena and Amazon Basins.
KEY TO THE SPECIES OF CENTROCHIR.
a. Depth about 4.2; scutes about 30; opercle granular; caudal with parallel stripes; dorsal and ventral
surfaces of the caudal peduncle partly covered by the fulcra.
.8. crocodili (Humboldt).

A REVIEW OF THE DORADIDÆ. /
315
8. Centrochir crocodili (Humboldt).
Plate 3, Fig. 4; Plate 5, Figs. 5 and 6; Plate 9, Figs. 4 and 5; Text-fig. 12.
Doras crocodili Humboldt, Rec. d'Observ. de Zool. et d’Anat. Comp., II, 1811, p. 181; Eigenmann, Mem.
Carnegie Mus., IX, 1922, p. 46 (Soplaviento; El Banco; Puerto Wilches; Puerto Berrio).
Doras longispinis Steindachner, Fisch-Fauna des Magdalenen stromes, 1878, p. 23, Pl. IV, Fig. 2, Pl. V,
Fig. 1 (Magdalena Basin).
Specimens Examined.
13555, I. U. M. 154–209 mm. El Banco, Rio Magdalena. Eigenmann.
13556, I. U. M. 141-194 mm. Puerto Berrio, Rio Magdalena. Eigenmann.
13557, I. U. M. 115–210 mm. Soplaviento, Rio Magdalena. Eigenmann.
Genus VI. PLATYDORAS Bleeker.
Doras Lacépède, Hist. Nat. Poiss., V, 1803, p. 116 (carinatus and costatus).
Doras Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 267 (carinatus and costatus).
Platydoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, pp. 16 and 86 (costatus).
Type, Doras costatus Linnæus.
Width at clavicle longer than head, over 3.6 in the length; lateral scutes numerous,
covering most of the sides over the anal and forward; in contact with modified caudal
fulcra above and below on the caudal peduncle, the three first in contact with the
dorsal plate. Adipose fin continued forward as a keel; head not much depressed,
arched in the occiput; snout moderately depressed; mouth subterminal, the lower
jaw a little the shorter; teeth well developed, in bands, those of the outer row enlarged
in the young; serration on posterior margin of the dorsal spine weaker than on the
anterior, disappearing with age; bones of the head, opercles, nasals and suborbital
pitted-granular; opercle striate; eye lateral, in about the middle of the head; anterior
nostrils close to the lips; fontanel without constriction; caudal emarginate; preorbital
in contact with the maxillary and premaxillary in front; the first suborbital between
the preorbital and the second suborbital; second suborbital little wider than the third,
the two forming the lower margin of the orbit.
Air-bladder double (3, Plate 2; 2, Plate 9), the anterior heart-shaped, with a
median longitudinal groove, without any cæca; posterior bladder subconical, with a
rounded base, without constriction or cæca.
Habitat: San Francisco, Paraguay, Amazon, and Orinoco basins; Guianas. The
most widely distributed genus.
KEY TO THE SPECIES OF PLATYDORAS.
a. A conspicuous light band from above the eyes along the middle of the sides through the caudal; scutes
28–31, leaving but a narrow naked area along the back; maxillary barbel reaching second fourth of
pectoral spine or tip of humeral process..
9. costatus (Linnæus).

316
A REVIEW OF THE DORADIDÆ.
aa. Sides plain or spotted.
b. Dark brown, rows of large white spots above and below the lateral line; smaller white spots on belly
and caudal; dorsal black with a few large white spots; maxillary with black and white rings; outer
surface of humeral process with two series of spines, reaching fourth lateral scute; 29 lateral scutes;
maxillary barbel reaching pectoral..
10. albomaculatus (Peters).
bb. Uniform blackish; dorsal fin white, its middle black; base of anal and two posterior rays white;
humeral process without spines, extending to last third of pectoral; 32 to 34 lateral scutes, those
on tail only half as deep as the tail; maxillary barbel reaching middle of pectoral spine; pectoral
reaching ventral...
11. helicophilus (Günther).
bbb. Brown, lighter below; a dark brown spot behind each lateral hook; caudal lobes with dusky bands;
humeral process reaching second lateral scute, with two series of spines; 31 scutes; maxillary
barbels to last third of pectoral spine. . .
12. dentatus (Kner).
9. Platydoras costatus (Linnæus).
Plate 1, Figs. 5 and 14; Plate 3, Figs. 1 and 2; Plate 5, Figs. 1 and 2;
Plate 9, Figs. 1-3.
Silurus costatus Linnæus, Syst. Nat., ed. 12, 1, 1766, p. 506.
Cataphractus costatus Bloch, Ausl. Fische, VIII, 1794, p. 82, Pl. 376.
Doras costatus Lacépède, Hist. Nat. Poiss., V, 1803, p. 116, part (South America); Cuvier and Valenciennes,
Hist. Nat. Poiss., XV, 1840, p. 268 (Guiana); Castelnau, Anim. Am. Sud. Poiss., 1855, p. 48 (Amazon);
Günther, Cat. Fish. Brit. Mus., V, 1864, p. 201 (British Guiana; River Cupai); Eigenmann and Eigen-
mann, Proc. Cal. Acad. Sci. (2), I, 1888, p. 161 (Rio Preto; Rio Puty; San Gonçallo; Xingu Cascade;
Obidos; Gurupa; Teffé); Occasional Papers Cal. Acad. Sci., I, 1890, p. 231; Perugia, Ann. Mus. Genova
(2), 1891, p. 34 (Villa Maria, Paraguay); Kindle, Ann. N. Y. Acad. Sci., VIII, 1895, p. 251 (Trocera
on the Tocantins); Eigenmann and Kennedy, Proc. Acad. Nat. Sci. Phila., 1903, p. 500 (Paraguay);
Eigenmann, Ann. Carnegie Mus., XXXI, 1907, p. 116 (Corumba; Laguna Ipacarai); Repts. Princeton
Univ. Exp. Patagonia, III, 1910, p. 393; Ribeiro, Peixes, IV, 1911, p. 210; Eigenmann, Mem. Carnegie
Mus., V, 1912, p. 185 (Twoca Pan and Gluck Island, British Guiana; Calobozo); Fisher, Ann. Carnegie
Mus., XI, 1917, p. 419 (Maciél, Rio Guaporé; San Joaquin, Bolivia; Santarem; Corumbá; Puerto
Suarez; Rio Jaurú, Paraguay Basin).
Platydoras costatus Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 16 (name only); Silures de Suriname, 1864,
p. 38 (Surinam).
Doras cataphractus (not of Linnæus) Schomburgk, Fishes Brit. Guiana, I, 1841, p. 158 (Rio Negro).
Doras armatulus Müller and Troschel, in Schomburgk, Reisen, III, 1848, p. 629 (Rupununi; Awaricuar).
Specimens Examined.
16170, I. U. M. 99, 118 and 132 mm. Porto Nacional, Rio Tocantins. Feb. 1924. Carl Ternetz.
16171, I. U. M. 184 mm. Peixe, Rio Tocantins. Carl Ternetz.
16187, I. U. M. 138 to 155 mm. Santarem market. Sept. 1924.
Sept. 1924. Carl Ternetz.
17041, I. U. M. 2, 185 and 217 mm. to end of middle caudal rays; Lake Rogoagua, Bolivia. Pearson.
12030, I. U. M. 1, 100 mm. Twoca Pan, Brit. Guiana. Wm. Grant.
12031, I. U. M. 1, 194 mm. Gluck Island, Brit. Guiana. Eigenmann.
15874, I. U. M. 3, 59-81 mm. Yarinacocha, Peru. Allen. Sept. 1920.
15875, I. U. M. 5, 77–81 mm. Rio Morona, Peru. Allen. Oct. 1920.
10139, I. U. M. 1, 88 mm. Corumba; Paraguay; Anisits.

A REVIEW OF THE DORADIDÆ.
317
D. I, 6; A. 11; scutes 2 or 3 + 28 to 30. Eye 4 to 6 in the head, 1.5-2.75 in the
snout, 1.3 to 2.75 in the interorbital; bones of head granular; mouth terminal, rather
narrow; teeth well developed, in narrow bands, the outer row of the upper jaw enlarged
in the young; maxillary barbel to the tip of the humeral process.
A pair of lateral white bands, diverging from the fontanel, passing along the
hooks of the scutes to the tip of the middle caudal rays; dorsal with a black spot near
the tips of the anterior rays; a pair of black bands along the caudal lobes.
Pectoral spine and innermost rays white, the middle rays black; anal and
ventrals with a large black spot; a light line forward from dorsal spine.
a
10. Platydoras albomaculatus (Peters).
Doras albomaculatus Peters, Mb. Ak. Wiss. Berlin, 1877, p. 470 (Calobozo).
Known only from the types, two specimens, the larger 70 mm. to base of caudal;
in the Berlin Museum.
11. Platydoras helicophilus (Günther).
Doras helicophilus Günther, Proc. Zool. Soc., London, XXXVII, 1868, p. 229 (Surinam).
Known only from the types, three specimens, 350 mm. long, in the British
Museum.
12. Platydoras dentatus (Kner).
Doras dentatus Kner, Sb. K. Akad. Wiss. Wien, XVII, 1855, p. 118, Pl. III, Fig. 3 (Surinam).
Known from the type, about 135 mm. long, in the Vienna Museum. It is
possibly the common P. costatus.
Genus VII. FRANCISCODORAS Eigenmann, gen. nov.
Type, Doras marmoratus Reinhardt.
Adipose fin high, longer than anal, not continued as a keel, or for a very short
distance only; dorsal spine serrate in front only; eye in front of middle of head;
caudal peduncle nearly completely covered with modified fulcra above and below,
the fulcra not in contact with the low lateral plates; fontanel not continued as a
groove behind the middle of the head; caudal deeply forked or deeply emarginate;
breast covered with skin; scutes large, heavy toward the end of the series.
In the general appearance, the nature of the skull, the single air-bladder, the
anterior scutes, etc., this genus resembles Centrochir.

318
A REVIEW OF THE DORADIDÆ.
13. Franciscodoras marmoratus (Reinhardt).
Plate 3, Fig. 7; Plate 22, Fig. 1; Text-fig. 12, B.
Doras marmoratus (Reinhardt, MS.) Lütken, Dan. Vidensk. Selsk. Skr., 1874, p. 30 (Rio das Velhas); id.,
1.c., 1875, p. 146, Pl. I, Fig. 1 (Rio das Velhas); Steindachner, Sb. Ak. Wiss. Wien, LXXI, 1875,
p. 147, Pl. IV; Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 237; Ribeiro,
Peixes, IV, 1911, p. 204, Pl. XXXVIII, Fig. 1; Fisher, Ann. Carnegie Mus., XI, 1917, p. 420 (Penedo;
Cidadedo Barra; Joazeiro).
As far as is known this species is confined to the Rio San Francisco. I have
examined some of the specimens in the Carnegie Museum.
Head 4.4; D. I, 6; A. 13; scutes 31 to 32, two scutes in contact with the dorsal plate;
eye 2.25 to 2.5 in snout, 6 to 7 in head, 2.33 in interorbital.
Genus VIII. LITHODORAS Bleeker.
Lithodoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 84.
Type, Doras dorsalis Cuvier and Valenciennes.
Width at clavicle greater than length of head, about 3.5 in the length; scutes few,
18 to 20, very narrow, with a single hook, the first two in contact with the dorsal
plate; adipose fin not continued as a ridge; snout truncate, not depressed, the occiput
roof-shaped; mouth terminal, the teeth well developed, in bands; bones almost
smooth; fontanel continued as a groove to the end of the nuchal plate; serræ on the
posterior margin of the dorsal larger than those of the anterior; eye large, lateral,
its center a little in advance of the middle of the head; suborbital bone large, reaching
the premaxillary and maxillary in front, with divergent ridges ending in points along
its free margin. Second suborbital narrower than the third, the first appearing as a
granular ridge below the preorbital; preopercle smooth; all the naked parts of the
body becoming more or less covered with granular scales with age.
14. Lithodoras dorsalis (Valenciennes).
Plate 2, Fig. 7; Plate 9, Fig. 6.
Doras carinatus Valenciennes, in Humb. Rec. d'Observ. Zool. et d’Anat. Comp., 1811, II, p. 184 (not Silurus
carinatus L.).
Doras dorsalis Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 284 (Cayenne); Kner, Sb. Ak. Wien,
XVII, 1855, p. 128 (Para); Günther, Cat. Fish. Brit. Mus., V, 1864, p. 205 (copied); Eigenmann and
Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 159; Occasional Papers Cal. Acad. Sci., 1890,
p. 225 (Pará); Ribeiro, Peixes, IV, 1911, p. 212, Pl. XXXIX (Tabatinga; 1 Pará); Fisher, Ann. Carnegie
Mus., XI, 1917, p. 419 (Pará).
1
1 Ribeiro records from Tabatinga a specimen 810 mm. to the last scute, 960 mm. to the end of the caudal. This is the
largest Doradid on record.

A REVIEW OF THE DORADIDÆ.
319
Doras papilionatus Filippi, in Guér. Ménev. Rev. and Mag. Zool., 1853, p. 167 (Amazons); Günther, 1.c.
(copied).
Doras lithogaster Heckel, MS. in Kner, Sb. Ak. Wien, XVII, 1855, p. 132 (Forte do Rio Branco); Günther,
1.c. (copied).
Lithodoras lithogaster Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 15 (name only).
Habitat: Para; Rio Negro; Cayenne.
Specimens Examined.
4248, I. U. M. one, 150 mm. Pará. Thayer Expedition?
4250, I. U. M. one, 171 mm. Brazil. Thayer Expedition.
16174, I. U. M. three, 128-164 mm. Belem, Para, market. 1924. C. Ternetz.
Head 4.33; D. I, 6; A. 13 or 14; scutes 2 + 16 to 20.
Snout short, not greatly depressed; occipital region distinctly roof-shaped.
Eye large, lateral, 5.33 in head, 2 in snout, 2 in interorbital; the posterior mar-
gin of the pupil in the middle of the head. End of fontanel a little in advance
of the posterior margin of the eye; a distinct groove from fontanel to the dorsal
plate.
Gill-opening extending down to the middle of the pectoral spine. Isthmus
almost equal to the length of the head; second scute about equal to the snout, 5th
about six-tenths as long; two feeble plates in front of the hook-bearing ones on a
straight line with the rest; caudal forked; mouth large, terminal; the lower jaw a
little shorter than the upper, teeth in bands, strong; width in front of the pectoral
a little greater than length of head; adipose equals anal, or shorter.
Genus IX. ACANTHODORAS Bleeker.
Type, Silurus cataphractus Linnæus.
Width at clavicle, 2.3 to 2.75 in the length; lateral plates numerous, covering
more than half of the sides; no plates on upper or lower surface of caudal peduncle;
adipose fin not continued forward as a keel; head depressed, the nuchal region but
slightly arched; mouth terminal, the mouth wider than the interorbital; teeth well
developed, in bands; no serræ on posterior margin of the dorsal spine; skull finely
granular (the granules along its edge, larger, sharper in spinosissimus); fontanel sub-
circular, not continued as a groove; eyes very small, lateral, far in advance of the
middle of the head; anterior nostril very near the lip; caudal rounded; opercle finely
striate in cataphractus, coarsely granular in spinosissimus; preopercle and inter-
operele similar; preorbital short, in contact with the premaxillary in front, expanded,
fan-like behind, with backward directed serræ on the outer half of the expanded edge;
first suborbital small, along the lower surface of the nasal, second and third of about

320
A REVIEW OF THE DORADIDÆ. .
equal size (with sharp granules, similar to those along the edge of the skull above the
eye in spinosissimus).
Coracoid entirely covered with skin or the tip finely granular.
First air-bladder short, heart-shaped; no trace of a second air-bladder.
Habitat: Amazon and Orinoco Basins; Guianas.
KEY TO THE SPECIES OF ACANTHODORAS.
a. A light line along the median spines of the lateral scutes and forward to, or near to, the eye; no plates on
caudal peduncle above or below.
b. Dorsal spine with a series of thorns along its anterior margin; lateral scutes 30, with a median hook
only, covering one third of the side, not meeting above or below on the caudal peduncle; maxillary
barbel reaching near tip of humeral process....
15. calderonensis (Vaillant).
bb. Dorsal spine with series of thorns on the front and on the sides; lateral scutes covering more than
half of the sides.
c. Last four or five pairs of scutes separated by the narrow laminate caudal fulcra, the anterior plates
of the caudal peduncle not quite meeting above and below; last scute narrow, with one hook;
maxillary barbel to the tip of the humeral process; black, a light median line on top of head;
a light line from posterior nostril along the edge of the granular part of the head and back along
the hooks of the lateral scutes to the caudal; fins barred with black and white.
16. cataphractus (Linnæus).
cc. Lateral plates of the caudal peduncle meeting above and below, only the last one separated from
its fellow by the caudal fulcra; last plate with several spines above and below the median hook;
maxillary barbel reaching to the origin of the humeral process; black, a light line on top of head
and a series of light spots along the middle of the back; lateral band similar to that of cata-
phractus, side of head and belly with conspicuous light spots; fins barred or spotted.
17. spinosissimus (Eigenmann and Eigenmann).
15. Acanthodoras calderonensis (Vaillant).
Plate 10, Fig. 5.
Doras calderonensis Vaillant, Bull. Soc. Philom., Ser. 7, IV, 1880, p. 154 (Calderon); Eigenmann and Eigen-
Occasional Papers, Cal. Acad. Sci., I, 1890, p. 234; Ribeiro, Peixes, IV, 1911, p. 206, Fig. 97.
Doras (Rhinodoras) depressus Steindachner, Flussf. Südam., II, 1881, 1, Pl. I, Figs. 3–3a (Lago Alexo).
Known from the types of calderonensis and depressus, the former in the Paris
Museum, the latter, one specimen, 103 mm., from Lago Alexo, in the Vienna Museum.
mann,
16. Acanthodoras cataphractus (Linnæus).
Plate 4, Fig. 5; Plate 10, Figs. 1-4.
Silurus cataphractus Linnæus, Syst. Nat., ed. 10, I, 1758, p. 307; ed. 12, I, 1766, p. 506.
Doras cataphractus Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 276 (?); Kner, Sb. Akad. Wiss.
Wien, XVII, 1855, p. 126 (Rio Guaporé; Barra do Rio Negro); Bleeker, Ichth. Arch. Ind. Prodr.,
I, 1858, p. 54; Günther, Cat. Fish. Brit. Mus., V, 1864, p. 204 (?); Eigenmann and Eigenmann, Oc-
casional Papers Cal. Acad. Sci., I, 1890, p. 234; Eigenmann, Repts. Princeton Univ. Exp. Patagonia,
III, 1910, 393; Ribeiro, Peixes, IV, 1911, p. 208; Fisher, Ann. Carnegie Mus., XI, 1917, p. 419 (Maciél,
Rio Guaporé).

A REVIEW OF THE DORADIDÆ.
321
Acanthodoras cataphractus Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 17; Silures de Suriname, 1864, p. 40
(Surinam); Eigenmann, Mem. Carnegie Mus., V, 1912, p. 188 (Kangaruma; Georgetown; Gluck
Island).
Cataphractus americanus Bloch and Schneider, Syst. Ichth., 1801, p. 107, Pl. 28; Lacépède, Hist. Nat. Poiss.,
V, 1803, p. 124, 127 (Carolina?).
Doras blochii Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 277 (copied).
? Doras castaneo-ventris Schomburgk, Fishes Brit. Guiana, I, 1841, p. 161, Pl. 3 (Rio Pasawiri).
? Doras brunnescens Schomburgk, Fishes Brit. Guiana, I, 1841, p. 163 (Upper Essequibo).
Doras polyramma et polygramma (Ex Heckel, MS.) Kner, Sb. Akad. Wiss. Wien, XVII, 1855, pp. 126, 127.
Callichthys asper Gronow, Cat. Fish., ed. Gray, 1854, 157.
12032, I. U. M. 5, 58–88 mm. Gluck Island. Eigenmann.
Head 3.8 in the length; D. I, 5; A. 10 or 11; scutes 2 or 3 + 22 to 27. Eye 9 to 10
in head, 2.5 to 3 in snout, 3.5 to 4.5 in interorbital; fontanel subcircular, top of head
scarcely arched; nuchal very little steeper; width at the clavicle equals distance from
snout to dorsal plate, 2.6 to 2.75 in the length; mouth terminal; teeth numerous,
bristle-like, in narrow bands.
Last scute of the caudal peduncle not extending over the entire depth of the
peduncle, with a median spine only.
а
17. Acanthodoras spinosissimus (Eigenmann and Eigenmann).
Plate 2, Fig. 3; Plate 11, Figs. 1 to 4; Text-fig. 12.
Doras spinosissimus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., 1888, p. 161; Occasional
Papers Cal. Acad. Sci., I, 1890, p. 235 (Coary); Ribeiro, Peixes, IV, 1911, p. 209; Fisher, Ann. Carnegie
Mus., XI, 1917, p. 420 (Maciél, Rio Guaporé). Ahl, Blätter Aquarien und Terrarienkunde 33,
1922, No. 1.
The type, a specimen 150 mm. long, in the Mus. Comp. Zoöl.
7167, C. M., 16005, I. U. M. 6, 50-111 mm. Maciél, Rio Guaporé. Haseman.
Head 3.6; D. I, 5; A. 11; scutes 21 to 23; eye 7.5 in head, 2.33 in snout, 3.5 in
interorbital; skull very similar to cataphractus but with coarser granulations; jaws
equal, mouth terminal, with well-developed teeth; width at clavicle 2.33–2.5 in the
length; maxillary barbel about reaching pectoral; the last four scutes extending
entirely across the caudal peduncle, with numerous spines; the last two separated
above by the fulcra; the next two or three pairs in contact above and below; several
pairs in front of the adipose in contact across the back.
Black, a light band along top of head; four light spots between dorsal and caudal
along the back; a light band from upper edge of opercle to base of caudal; dorsal and
pectoral with white spots or partial bars; ventral surface black, with irregular white
spots; barbels all black and white banded.

322
A REVIEW OF THE DORADIDÆ.
Genus X. AGAMYXIs Cope.
Agamyxis Cope, Proc. Am. Philos. Soc., XVII, 1878, p. 101.
Type, Agamyxis pectinifrons Cope.
Eye moderate, entirely in anterior half of head, surrounded by serrate ridges;
adipose fin not continued forward as a ridge; dorsal spine as long as pectoral spine,
serrate in front and on the sides, smooth behind; lateral scutes covering entire side of
caudal peduncle and more than upper half of area between anal and tip of humeral
process; caudal peduncle with spiniferous plates above and below; nasal erect, pecti-
nate; caudal rounded; breast covered with skin.
This genus differs from Acanthodoras largely in having the caudal peduncle
covered with plates above and below.
1
KEY TO THE SPECIES OF AGAMYXIS.
a. Black, lower parts spotted with white, dorsal, anal, ventral and caudal with a yellowish cross bar; head
3.6; pectoral spine 3.2; eye 1.75 in snout, 6 in head; orbital margin raised, granulate, or pectinate;
preopercular margin granular, the angle serrate; maxillary barbel not quite reaching base of pectoral
spine. Scutes 27; caudal peduncle with spiniferous plates above and below.
18. pectinifrons 1 (Cope).
aa. Dark brown with irregular yellow spots scattered over entire body and fins; pectoral spine with cross
bars; head 3.2; pectoral spine 3; eye 7.6 in the head, about 2.3 in the snout; orbital margin scarcely
raised, prenasal bone moderately so; maxillary barbel extending beyond origin of pectoral; a blunt
keel along the middle of the head, strongest on occipital region, fading out and dividing forward;
teeth on the anterior edge of the dorsal stronger than those on the sides; 3 + 26 scutes, 4 to 5 spinif-
erous plates above and below on the caudal peduncle, continuous with the fulcra; types 90 and 110 mm.
19. flavopictus (Steindachner).
18. Agamyxis pectinifrons (Cope).
Plate 16, Fig. 4.
Doras pectinifrons Cope, Proc. Am. Philos. Soc., XI, 1870, p. 568 (Pebas, Ecuador); Proc. Acad. Nat. Sci.
Phila., 1871, Pl. 3; Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 241.
ame
ca.
7777777777
erum
Fig. 19. Agamyxis pectinifrons Cope. The type in the collection of the Academy of Sciences, Philadelphia.
Sketch of the type.
1 In the original description Cope states "dorsal and pectoral spines elongate, both serrate before and behind."

A REVIEW OF THE DORADIDÆ.
323
Agamyxis pectinifrons Cope, Proc. Am. Philos. Soc., XVII, 1878, p. 679 (new genus).
Known from the type, 76 mm. long, in the collections of the Philadelphia Academy
of Sciences.
19. Agamyxis flavopictus (Steindachner).
Doras (Agamyxis) flavopictus Steindachner, Sitzb. K. Akad. Wiss. Wien, 1908, No. VII, p. 3 (Iquitos).
Known from the types, two specimens 90 and 110 mm. long, from Iquitos in the
Vienna Museum.
Genus XI. ASTRODORAS Bleeker.
Astrodoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 17.
Type, Doras asterifrons Kner.
Width at clavicle 2.6 in the length; lateral plates numerous, covering half or
more than half of the sides; caudal fulcra laminate, covering about half the caudal
peduncle above and below; adipose fin not continued forward as a keel; head de-
pressed, nuchal region roof-shaped; mouth terminal, equal to interorbital; teeth in
bands; serræ on anterior margin of the dorsal spine, none on the sides or behind;
skull finely granular or striate; fontanel elongate, continued as an obscure, inter-
rupted groove; eye moderate, in center or a little in front of center of the head;
anterior nostril near lip; caudal emarginate; preorbital short, in contact with the
anterior horn of the ethmoid in front, its expanded posterior edge erect, with about 10
spines; suborbitals narrow, of equal width, the middle one granular. The anterior
air-bladder heart- to kidney-shaped, merging into the posterior bladder without
constriction. The latter forked to its base, the horns turned laterad, the tips slightly
forward in a specimen No. 16003 I. U., from Jutahy; consisting of a short, minute,
unforked diverticulum in two specimens No. 7163 C. M., from Santarem.
20. Astrodoras asterifrons (Heckel).
Plate 1, Fig. 11; Plate 4, Figs. 2 and 4.
Doras asterifrons Heckel MS., in Kner, Sb. Ak. Wiss. Wien., XVII, 1855, p. 123, Plate II, Fig. 2 (Barra do
Rio Negro; Guaporé); Günther, Cat. Fish. Brit. Mus., V, 1864, p. 203 (Rio Cupai); Eigenmann and
Eigenmann, Occasional Papers Cal. Acad. Sci., 2d Ser., I, 1890, p. 241 (Jutahy; Teffé; Porto do Moz;
Serpa); Ribeiro, Peixes, 1911, p. 202, Fig. 96; Fisher, Ann. Carnegie Mus., XI, 1917, p. 420 (Maciél,
Rio Guaporé; Santarem; San Joaquin).
Specimens Examined.
16003, I. U. M. one, 97 mm. to end of longest ray of upper caudal lobe. Jutahy. Thayer Expedition.
7163, C. M. 4, 67 to 89 mm. Santarem. Haseman.
Head 4; D. I, 6; A. 12; scutes 2 or 3 + 24 or 25, over half the depth; the rudi-
mentary scutes on the tympanum above the line of the lateral hooks.
Eye 1.25 in snout, 5 in the head, 1.33 in the interorbital.

324
A REVIEW OF THE DORADIDÆ.
Width at clavicle slightly greater than distance from snout to posterior edge of
dorsal plate; interorbital concave, the supercilian ridge raised; caudal fulcra laminate,
the anterior ones above and below modified into a plate about the size of the eye,
near the middle of the caudal peduncle; dorsal spine with two keels on each side;
dorsal spine reaching nearly to or beyond origin of adipose; nasal erect, with about
12 spines; last three or four scutes with the median hook only; mouth terminal,
teeth in narrow bands, the jaws equal; the abdominal area short; distance between
tips of coracoids about 1.33 in distance from symphysis of coracoids to the anus;
mottled ashen, darker above than below; fins spotted.
The difference in the air-bladders of the specimens from Jutahy and Santarem
is so great that an unusually careful examination was made but yielded only the
following differences:
a. Dorsal spine equal to its distance from the anterior edge of the eye; distance between the tips of the
coracoids equals the distance between snout and end of dorsal plate; dorsal spine to middle of adipose.
Second air-bladder consisting of two sausage-shaped tubes directed sideways. 16003, Jutahy specimen.
aa. Dorsal spine less than its distance from the anterior edge of the eye; distance between the tips of the
coracoids equal to less than the distance from the symphysis of the coracoid to the base of the ventrals;
greatest width a trifle less than the distance between the snout and the end of the dorsal plate; dorsal
to or not quite to the adipose. Second air-bladder consisting of a short median protuberance. 7163
C. M., Santarem specimens.
Dorsal spine equals its distance from the nasal crest, reaching to the adipose
according to the figure of the type.
Genus XII. SCORPIODORAS Eigenmann, gen. nov.
Type, Doras heckelii Kner.
Having the characters of Astrodoras, except that the mouth is wider than the
interorbital; nasal procumbent, the expanded edge raised but little; with more than
25 spines.
Anterior air-bladder kidney-shaped, large, its length about 1.5 in its width;
posterior air-bladder banjo-or scorpion-shaped, the body of it heart-shaped, a posterior
horn longer than the main part, recurved like the whip of a scorpion.
21. Scorpiodoras heckeli (Kner).
Plate 1, Fig. 30, Text-fig. 12, D.
Doras heckelii Kner, Sb. Akad. Wiss. Wien, XVII, 1855, p. 125, Fig. 4 (Rio Negro); Günther, Cat. Fish.
Brit. Mus., V, 1864, p. 204; Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890,
p. 243 (Jutahy; Tonantins; Teffé; Tabatinga); Ribeiro, Peixes, IV, 1911, p. 205, Pl. XXXVIII, Fig. 2.
Habitat: Amazon basin.
16002, I. U. M. one, 161 mm. Teffé. Thayer Expedition.

A REVIEW OF THE DORADIDÆ./
325
Head 4.33; width at the clavicle 3.14 in the length, 1.25 in the distance between
snout and edge of dorsal plate; D. I, 6; A. 11, scutes 2.5–3 in the depth, 4 + 29, those
on the tympanum above the line of the hooks on the scutes; last five scutes without
supplementary hooks; mouth terminal, the jaws equal; teeth numerous; nasal sub-
erect, curved so that it seems continuous with the suborbital, with about 25 spines;
the superciliary edge not raised; caudal fulcra laminate, the anterior ones not enlarged;
dorsal spine with several ridges on the sides, not reaching adipose.
Abdominal area long, the distance between the tips of the coracoid processes
2 in the distance between the coracoid symphysis and the anus. Maxillary barbel
extending past tip of humeral process.
Rust colored, the fins spotted; caudal with two longitudinal bands; ventral
surface speckled.
Genus XIII. AMBLYDORAS Bleeker.
Amblydoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 86 (affinis).
Zathorax Cope, Proc. Acad. Nat. Sci. Phila., 1872, p. 271.
Type, Doras affinis Kner Doras hancocki Cuv. and Val.
Width at clavicles 3 in the length; coracoid very much wider than clavicle, the
surfaces of the two granular, the space for the ventral part of pectoral muscles reduced
to a narrow tube in the anterior part of the thoracic buckler; scutes numerous, covering
more than half the sides; caudal fulcra not covering half the caudal peduncle; adipose
fin not continued forward as a keel; dorsal spine without hooks or thorns, grooved
and ridged on sides and front; head depressed, the skull arched, finely striate-granular,
without a median groove; eye in middle of head; anterior nostril near the lip; mouth
terminal, the teeth well developed, in narrow bands; fontanel elongate; preorbital
in contact with the premaxillary in front, its spines (about 15) covered; suborbitals
narrow, of uniform width.
Anterior air-bladder in hancocki short, heart-shaped, without cæca. No posterior
air-bladder.
Habitat: Guianas; Amazon.
a
KEY TO THE SPECIES OF AMBLYDORAS.
a. Maxillary barbel to posterior margin of orbit; pectoral spine reaching beyond ventrals; width at the
clavicle 2.66 in the length; pale brown, the pectoral spine spotted with dark......22. monitor (Cope).
aa. Maxillary barbel reaching tip of humeral process; width at clavicle 3 in the length; pectoral spines
reaching beyond base of ventrals; an irregular black band along sides below the median hooks. Three
more or less distinct black blotches on the back, the last across the caudal peduncle.
23. hancocki (Cuvier and Valenciennes).

326
A REVIEW OF THE DORADIDÆ.
22. Amblydoras monitor (Cope).
Plate 16, Fig. 3; Text-fig. 20.
Zathorax monitor Cope, Proc. Acad. Nat. Sci. Phila., 1871, p. 271, Pl. 4, Fig. 1 (Amazon).
Doras monitor Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 245.
Known only from the type in the collection of the Philadelphia Academy of
Sciences.
C.
SUMMA
Fig. 20. Amblydoras monitor (Cope). Sketch of thorax and lower side of head.
23. Amblydoras hancocki (Cuvier and Valenciennes).
Plate 3, Fig. 9; Plate 13, Figs. 1 to 4.
Doras costata Hancock, Zoöl. Journ., IV, p. 242 (Demerara).
Doras hancockii Cuvier and Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 279; Günther, Cat. Fish. Brit.
Mus., V, 1864, p. 202 (Demerara; Rio Cupai); Eigenmann, Mem. Carnegie Mus., V, 1912, p. 187
(Lama Stop-Off; Maduni Creek; Wismar; Rockstone; Gluck Island; Tumatumari; Rupununi Pan);
Ribeiro, Peixes, IV, 1911, p. 210.
Doras affinis Kner, Sb. Ak. Wiss. Wien, XVII, 1855, 121, Pl. 11, Fig. 1 (Rio Branco; Guaporé); Günther,
Cat. Fish. Brit. Mus., V, 1864, p. 202; Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci.,
I, 1890, p. 238; Ribeiro, Peixes, IV, 1911, p. 201, Fig. 75.
Amblydoras affinis Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 17.
Doras truncatus Bleeker, 1.c., p. 18.
Habitat: Guiana to Guaporé.
Specimens Examined.
12033, I. U. M. 8, largest 110 mm. Lama Stop-Off near Georgetown, Brit. Guiana. Eigenmann.
12034, I. U. M. 2, 103 and 118 mm. Maduni Creek near Georgetown. Eigenmann.
12035, I. U. M. 3, about 37 mm. Rockstone on the Essequibo, Brit. Guiana. Eigenmann.
12036, I. U. M. one, 71 mm. Tumatumari on the Potaro, Brit. Guiana. Eigenmann.
12037, I. U. M. 2, 36 and 40 mm. Rupununi Pan, Brit. Guiana. Eigenmann.
15887, I. U. M. one, 65 mm. Itaya above Iquitos, Peru. Allen.
17040, I. U. M. 17, 60-98 mm. Lagoon near Reyes, Bolivia, Oct. 1921. Pearson.
Head 4 to 4.3; D. I, 6; A. 11 to 13; eye 4.5 in the head, 1.5 in the snout, 1.5 in
the interorbital; width of the clavicle 3 in the length.

A REVIEW OF THE DORADIDÆ.
327
Maxillary barbel about to tip of humeral process; scutes about half as deep as
the body; caudal fulcra laminate, none converted into a plate; caudal slightly emargi-
nate; a light line along the scutes; a black stripe from humeral process to end of anal
below the scutes; a black band across caudal behind the last scute, a number of
saddle-shaped spots on middle of back; upper parts dark ashy with a few spots
smaller than pupil; spots on dorsal and caudal.
Genus XIV. ANADORAS Eigenmann, gen. nov.
Type, Doras grypus Cope.
Width between clavicles less than 3 in the length; scutes numerous, covering
less than one fourth of the sides; modified fulcra covering much of the caudal peduncle
above and below.
Adipose fin short; not continued as a keel; dorsal spine grooved; without serræ;
no plates between the dorsal and adipose; granulations on breast inconspicuous,
narrow, or confined to the tip of the coracoid. Eye entirely in anterior part of the
head; preorbital bone inconspicuous, snout depressed, mouth terminal; teeth minute,
in bands; fontanel oval, not continued as a groove; head minutely granular.
First air-bladder heart-shaped, with a median, longitudinal groove, without
marginal prolongations; second air-bladder reduced to a minute tubule (weddellii)
or entirely suppressed (regani, grypus) (5, Text-fig. 2).
Habitat: Amazon Basin.
KEY TO THE SPECIES OF ANADORAS.
a. Sides with a pale lateral band.
b. Dorsal region copper-colored, with few faint or sepia spots; lateral plates yellow, the region below brown-
ish yellow; caudal with dusky stripes along the upper and lower lobes; lateral plates 3 + 26–27, nar-
row, leaving wide naked areas above and below. Eye small, 6 in head, 2 in interorbital, 1.5 in snout;
interorbital flat; maxillary barbel extending beyond base of pectoral; each lateral plate with one
or two points above and below the median hook. Caudal peduncle with 7-10 bony plates, grading
into the fulcra above and below; caudal emarginate; caudal lobes with violet bands. 90 mm.
24. regani (Steindachner).
bb. Three or more dark blotches, below the band, on a light background; the dark above the band with
darker, light-edged, blotches; anterior parts of dorsal, anal and ventrals black, the posterior part
light, spotted; middle and edges of caudal light, the base and a stripe along the lobes black; coracoid
process flaring backward; distance from union of coracoids to the line uniting the tips one half to
one third the distance between the tips; caudal deeply emarginate..
.25. grypus (Cope).
bbb. Brown above, with a yellow lateral band; caudal with vertical dark bars. Orbit 1 in interorbital,
3 in head; maxillary barbels reaching end of pectoral spines; caudal truncate, scutes 26, leaving
a broad naked band above and below, with only a single median spine. 82 mm.
26. nauticus (Cope).
22

328
A REVIEW OF THE DORADIDÆ.
a
aa. Sides without a lateral stripe.
c. Irregularly spotted; maxillary barbel reaching pectoral spine; opercle granular; eye 3 to 4 in inter-
orbital; nasal without a serrated crest; fontanel oval, with a granular border; coracoid processes
flaring but little; the distance between the juncture of the coracoids and a line connecting their
tips to Z of the distance between the tips; outer face of striate portion of the coracoid convex;
scutes 25-27; the caudal fulcra more plate-like than in grypus, covering most of the caudal
peduncle.....
27. weddellii (Castelnau).
cc. Yellowish with sepia markings, 4 bars on dorsal spine, 5 on pectoral, 4 on posterior part of body;
maxillary barbel reaching tip of humeral process; opercle striate; nasal strongly pectinate;
opercle reticulate; eye 1.75 in interorbital; scutes 29, with an auxiliary spine above and below;
top of head striate; coracoid process reaching middle of pectoral spine; the humeral process
beyond the third quarter of that spine; caudal peduncle with six plates... 28. insculptus (Ribeiro).
24. Anadoras regani (Steindachner).
Text-fig. 21.
Doras regani Steindachner, Sitzb. K. Akad. Wiss. Wien, 1908, Nr. XI (Pará).
Known from four specimens, 90 mm. long, in the Vienna Museum, and 16191,
I. U. M. 2, 123 and 140 mm. Santarem market.
Santarem market. Sept. 1924. C. Ternetz.
Fig. 21. Anadoras regani (Steindachner). 140 mm. Photo by N. E. Pearson.
25. Anadoras grypus (Cope).
Plate 4, Fig. 7; Plate 15, Figs. 1 to 3.
Doras grypus Cope, Proc. Acad. Nat. Sci. Phila., 1871, p. 270, Pl. XV, Figs. 1-1a (Ambyiacu River).
Doras weddellii Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 239 (in part).
Specimens Examined.
4249, I. U. M. one, 129 mm. Teffé. Thayer Expedition.
15849, I. U. M. 50 to 122 mm. to end of middle caudal rays. Lake Cashiboya. Allen.
15961, I. U. M. 3, 80 to about 150 mm. Iquitos. Morris.
Head nearly 4 in the length; D. I, 6; A. about 12; width at clavicle nearly 3 in
the length; eye 5.6 in the head, 1.75 in snout, 2.75 in interorbital; maxillary barbel
reaching beyond base of pectoral spine; mouth terminal, the teeth in narrow bands;

A REVIEW OF THE DORADIDÆ.
329
scutes 26 or 27, narrow, about 3 in the depth; rudimentary scutes feeble, concealed;
laminate caudal fulcra covering about half the caudal peduncle above and below;
nasal bone not serrate; skull finely granular. For color see the key.
26. Anadoras nauticus (Cope).
Zathorax nauticus Cope, Proc. Acad. Nat. Sci. Phila., 1874, p. 133 (Nauta); Proc. Am. Philos. Soc., XVII,
1878, p. 678; Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 246.
Known from the type, 82 mm. long, in the Philadelphia Academy of Natural
Sciences.
27. Anadoras weddellii (Castelnau).
Plate 4, Fig. 6; Plate 15, Fig. 4.
Doras weddellii Castelnau, Anim. Amer. Sud., 1855, p. 48, Pl. XVII, Fig. 1 (Chiquitos); Günther, Cat.
Fish. Brit. Mus., V, 1864, p. 203 (Santarem); Vaillant, Bull. Soc. Philom., Ser. 7, IV, 1880, p. 154
(Calderon); Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, 163 (in part); Oc-
casional Papers Cal. Acad. Sci., I, 1890, p. 239 (the specimens with a restricted coracoidal striation)
(Fonteboa; Teffé; Serpa; Porto do Moz; Silva, L. Saraca); Ribeiro, Peixes, IV, 1911, p. 202; Fisher,
Ann. Carnegie Mus., XI, 1917 (Manaos; Santarem; Rio Jauru; Bastos, Rio Alegre and Maciél into
Guaporé; San Joaquin, Bolivia).
Specimens Examined.
5110, I. U. M. 2, 112 and 113, the smaller a skeleton. Island Marajo. Thayer Exp.
10218, I. U. M. one, about 75 mm. to end of middle caudal rays. Rio Pilcomayo.
Head 3.66; clavicular width about 3 in the length; eye 7 in the head, 2 in the
snout, 3 in the interorbital. D. I, 6; A. 12; scutes 3 + 26 or 27, one fourth or one fifth
of the depth of the body; caudal fulcra heavy, laminate, reaching to the adipose and
nearly to the anal; mouth terminal; teeth well developed, in bands; nasal not serrate.
a
28. Anadoras insculptus (Ribeiro).
Plate 14, Figs. 1 to 3.
Doras insculptus Ribeiro, Comm. Linhas. Telegr. Estrat. Matto Grosso as Amazonas, Annexo 5, 1912, p. 22
(Manaos).
Known from the types, the largest 100 mm., in the Mus. Nacional Rio de Janeiro.
I am indebted for the figures to Dr. A. Ribeiro.
Genus XV. HYPODORAS Eigenmann, gen. nov.
Type, Hypodoras forficulatus Eigenmann.
Adipose fin but little shorter than the anal fin, the anterior two thirds covered
by a rhomboidal plate; caudal fulcra laminate, covering the entire caudal peduncle
above and below; dorsal spine striate in front and on the side, without serræ; lateral
scutes of the caudal peduncle in contact with the plates above and below, with a

330
A REVIEW OF THE DORADIDÆ.
single hook; those in front of the caudal peduncle with 2 to 5 hooks above the median
one and with 1 to 2 below it; humeral process very strong, with a series of spines;
process of coracoid striate; eye immediately in front of the middle of the head; pre-
orbital crest pectinate; suborbital granular.
Anterior air-bladder (Fig. 4, Plate 2) wider than long, kidney-shaped, without
marginal tentacles or cæca, with a median longitudinal constriction, directly con-
tinued into the posterior air-bladder, which, at the point of union, is about one third
as wide as the anterior and forked (divided into two horns) in its posterior three fifths.
The horns seem to be continuations of the two lateral lobes of the anterior bladder.
One of the horns is turned sidewards.
This genus differs from all the others of the Doradidæ in the plate over the
anterior part of the adipose and in the nature of its air-bladder.
29. Hypodoras forficulatus Eigenmann, spec. nov.
Plate 4, Fig. 1; Plate 25, Fig. 3; Text-fig. 12, I.
15876, I. U. M. one, type, 123 mm., 104 mm. to end of last scute. Iquitos. Allen. Sept. 1920.
This species has the general appearance of Anadoras grypus Cope but differs
from grypus very notably. The data in parentheses refer to a specimen of D. grypus,
108 mm. long to the end of the last scute.
Head 3.8; depth 5.3; D. I, 6; A. 11; scutes 2 + 26. Top of head granulose, the
fontanel not continued as a groove; prenasal bone deeply pectinate (smooth); humeral
region very wide; equal to the distance from snout to dorsal fulcrum; interorbital
equals snout (snout and eye); eye 2.66 in interorbital, 6 in the head; teeth minute,
in bands; maxillary barbel extending a little beyond coracoid process, banded; outer
mental barbel reaching coracoid, inner mental barbel considerably shorter; dorsal
spine deeply striate in front and on the sides, smooth behind, a little over half as
long as the heavy, serrate, pectoral spine, which reaches the middle of the ventrals;
ventrals broad, rounded; anal rounded; caudal truncate; dorsal and pectorals lanceo-
late; humeral process very strong, reaching to below 4th dorsal ray, with teeth toward
its tip equal to those of the pectoral which oppose them; coracoid process striate,
narrow, reaching about to third fifth of the pectoral spine; caudal peduncle covered
with plates below (naked); a single large plate between the adipose and the numerous
caudal fulcra (none); a very large keeled plate over anterior part of the adipose (none);
scutes very high (low), covering the entire sides, two or three from the dorsal plate
to the humeral process, those of the sides crowded; the median spine moderate, with
up to 5 smaller spines above the larger one and two, rarely three, below the main
spine in the region of the anal (none); one or none on the caudal peduncle above and

A REVIEW OF THE DORADIDÆ.
331
below the central spine; the central spines of nearly uniform size from below the
dorsal to the caudal; ashen, a narrow black bar from posterior half of dorsal down and
back to a black spot at the end of the humeral process, then downward and forward
to the edge of the belly; a wider bar downward and forward from the soft part of
the adipose, then to and partly across the base of the anal; a bar across the middle of
the caudal peduncle and another across the base of the caudal; dorsal black; the
distal part hyaline, spotted with black; caudal, anal, ventrals and pectorals hyaline,
with black spots, bases of caudal, anal and ventrals with a larger black spot; ventral
surface dark, clouded.
Genus XVI. PHYSOPYXIs Cope.
Physopyxis Cope, Proc. Acad. Nat. Sci. Phila., 1871, pp. 112, 272, 273.
Type, Physopyxis lyra Cope.
Eye small, in anterior half of head; no adipose; dorsal spine serrate on lower
half of anterior margin; pectoral spine extending beyond origin of anal; caudal
truncate; clavicles and coracoid granular, developed into a large armor.
30. Physopyxis lyra Cope.
Plate 16, Figs. 1 and 2. Text-fig. 22.
Physopyxis lyra Cope, 1.c. (Ambyiacu River).
This species is known from the type 35 mm. long in the collections of the Phila-
delphia Academy of Sciences.
Fig. 22. Dorsal spine of the type of Physopyxis lyra.
Genus XVII. PSEUDODORAS Bleeker.
Pseudodoras Bleeker, Ichthyol. Arch. Indici Siluri, 1858, p. 53 (to include Doras niger Valenciennes; D. brevis
Kner, D. humeralis Kner; D. lipophthalmus K.).
Oxydoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 14 (type, Doras niger Val. = Pseudodoras niger
Bleeker).
Type, Doras niger Valenciennes.
Bleeker in 1858 based his Pseudodoras on Doras niger Val., D. brevis Kner,
D. humeralis Kner and D. lipophthalmus Kner, in the order named. This is a miscel-
a

332
A REVIEW OF THE DORADIDÆ.
laneous collection of fishes, evidently known to Bleeker only as a series of names.
There is no evidence that Bleeker considered the Doras niger as anything except
Valenciennes' species which should remain the type of the name Pseudodoras. If
there is any doubt on this score it is removed by Bleeker (1863, p. 14) when he dis-
tinctly states that his Pseudodoras niger is the Doras niger of Val. and not the Doras
niger of Kner.
In Nederl. Tijdsch. Dierk., I, 1863, pp. 12, 14, he endeavored to suppress his
Pseudodoras: “De plus ma première espèce de Pseudodoras est le Doras niger, pour
lequel le nom d'Oxydoras a droit de priorité, et les trois autre espèces, ainsi que le
Hemidoras stenopeltis sont de vrais Doras, tel que je comprends actuellement le genre
Lacépèdien, dont en effet le Doras carinatus espèce voisine, est le type.”
Bleeker, however, is wrong in assuming that the name Oxydoras of Kner has
priority to the name Doras niger Valenciennes. Kner did not know Doras niger of
Valenciennes when he framed his name Oxydoras, he simply mistook specimens of
another species for it. The Doras niger Val. cannot be made the type of Oxydoras.
Doras niger of Kner is not the Doras niger of Valenciennes, a fact Bleeker had dis-
covered by 1863. On p. 14, 1863, Bleeker makes Doras niger Val.—a species not
known to Kner—the type of Kner's Oxydoras, but he reconsidered this and on page 85,
he distinctly makes Doras (Oxydoras) niger Kner (= Oxydoras kneri Bleeker) the
type of Oxydoras. As this was the first and a perfectly legitimate restriction of the
genus Oxydoras, 0. kneri should remain the type of Oxydoras. Since the Doras niger
of Kner belongs to a genus distinct from the Doras niger of Valenciennes there is no
reason why the name Pseudodoras, with Doras niger of Valenciennes as its type, should
be suppressed and it is herewith resurrected.
Width at clavicles less than length of head; coracoid covered with skin; lateral
plates few, narrow, 3 + 18 to 23; adipose fin continued forward as a keel; head not
depressed, snout conical; mouth inferior; premaxillaries rhomboidal; teeth feeble;
serration on posterior margin of dorsal spine weaker than on the anterior; occipital
region roof-shaped, granular or striate, without a median groove; eyes lateral, entirely
behind the middle of the head; anterior nostril remote from the lips; fontanel double;
caudal emarginate; opercle striate; suborbital granular in old. Several tentacles
across the roof of the mouth between the second and third pairs of gill-arches, two
rows of tentacles converging from in front of the first arch forward, ending in a ridge;
smaller ones on the floor of mouth opposite; preorbital comma-shaped, the front
incurved, connected with the ethmoid. First suborbital in part under the preorbital,
the second large, only half of it forming part of the orbital border, the third very
slender (3, Plate 11).
a

A REVIEW OF THE DORADIDÆ.
333
Air-bladders of P. niger (Fig. 4, Plate 2) both well developed, with marginal
indications of lobules or beginnings of cæca. Anterior bladder elongate, heart-
shaped, its width 1.25 in its length. Posterior bladder elliptical, a little more than
twice as long as wide; its length less than 2 in the length of the anterior.
The generic description is based on P. niger.
KEY TO THE SPECIES OF PSEUDODORAS.
a. Gill-opening extending far below pectoral spine; dorsal spine with feeble teeth on the distal part of the
posterior margin, disappearing with age; no conspicuous caudal fulcra; occipital region steeply roof-
shaped; eye in posterior half of head, 3-4 in interorbital; highest scutes 1.3-1.5 in interorbital; three
small bones in front of the hook-bearing ones; width in front of pectoral equals head less one fifth to
three fifths of opercle. (A small granular plate between the upper halves of the first two hook-bearing
lateral scutes in the old.). .....
.....31. niger (Valenciennes).
aa. Gill-openings extending to the base of the pectoral spine; dorsal spine smooth behind (?); caudal fulcra
extending halfway to anal and adipose; occipital region obtusely roof-shaped; eye just behind the
middle of the head, 3 in the interorbital; scutes 16, high; two small bones in front of the spine-bearing
scutes. A golden stripe along middle line from dorsal to end of adipose, an ill-defined dark stripe
along the middle of the head; lateral parts of top of head, middle of opercle, lower part of cheeks and
lateral plates golden...
32. huberi (Steindachner).
31. Pseudodoras niger (Valenciennes).
Plate 1, Fig. 16; Plate 17, Figs. 1-4; Plate 23, Fig. 1; Text-figs. 2, 6, 7 and 10.
Doras niger Valenciennes, in Humboldt, Rec. d'Observ. Zool. et Anat. Comp., II, 1811, p. 184; Cuvier and
Valenciennes, Hist. Nat. Poiss., XV, 1840, p. 291 (?); Schomburgk, Fishes Brit. Guiana, I, 1841, p. 165;
Müller and Troschel, in Schomburgk, Reisen, III, 1848, p. 629 (Rivers of Guiana); Bleeker, Nederl.
Tijdsch. Dierk., I, 1863, p. 14 (name only); Eigenmann, Mem. Carnegie Mus., V, 1912, p. 190
(Rupununi).
Rhinodoras niger Günther, Cat. Fish. Brit. Mus., V, 1864, p. 209 (Amazons); Cope, Proc. Am. Philos. Soc.,
XVII, 1878, 678 (Nauta); Vaillant, Bull. Soc. Philom. (7), IV, 1880, p. 14 (Calderon).
Oxydoras niger Eigenmann and Eigenmann, Proc. Cal. Acad. Sci. (2), I, 1888, p. 159 (Teffé; Gurupa;
Manacapuru; Coary; Obidos); Occasional Papers Cal. Acad. Sci., I, 1890, p. 247; Kindle, Ann. N. Y.
Acad. Sci., VIII, 1894, p. 251 (Pará); Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910,
p. 393; Ribeiro, Peixes, IV, 1911, p. 193, Pl. XXXVII; Fisher, Ann. Carnegie Mus., XI, 1917, p. 420
(Santarem; Manaos).
Doras humboldti Agassiz, Selecta Gen. et Spec. Pisc. Bras., 1829, p. 129, Pl. 5 (Rio San Francisco, Brazil);
Agassiz, A Journey in Brazil, 1868,
Corydoras edentatus Spix, Selecta Gen. et Spec. Pisc. Bras., 1829, Pl. 5.
Rhinodoras prionomus Cope, Proc. Acad. Nat. Sci. Phila., 1874, p. 134 (Nauta); Proc. Am. Philos. Soc.,
XVII, 1878, 678 (Nauta).
Rhinodoras teffeanus Steindachner, Sb. Akad. Wiss. Wien, LXXI, 1875, 145, Pl. 3 (Teffé).
This species is known from near sea level to about 3000 feet. In British Guiana,
the Amazons from Pará westward to the Marañon, from the Rio San Francisco, and
from the following specimens in the collections of Indiana University:
--

334
A REVIEW OF THE DORADIDÆ.
5105, I. U. M. one, 234 mm. to end of middle caudal rays. Pará.
Pará. Thayer Exp.
15651, I. U. M. 15960, 4, 170-260 mm. Iquitos. Allen, 1920, Morris, 1922.
,
15450, I. U. M. one, about 250 mm. Yarinacocha. Allen. Sept. 1920.
15845, I. U. M. one, about 200 mm. Lake Cashiboya.
Lake Cashiboya. Allen. 1920.
15850, I. U. M. one, skin, 202 mm. from snout to end of dorsal plate, along the median line; about 650 mm.
over all. La Merced, Peru, 2500 feet. Sr. Ecuador Præli. 1918.
16004, I. U. M. one, 273 mm. to end of the scutes. Rio Pacaya. Allen.
743, T. R. S. one, skin, 965 mm. to end of caudal, Kartabo, Guiana. Beebe.1
16169, I. U. M. one, 453 mm. Santarem. 1924. Carl Ternetz.
2
LOCALITY: Kartabo, Bartica District, British Guiana. Date: 24, VIII, 1922.
.
Dimensions: From field measurements.
In mm.
Length...
.. 840
Head.....
... 245
Depth (in front of dorsal fin)...
.. 169
Greatest width (anterior to pectoral fins)
175
Depth of caudal peduncle. ....
41
Width of caudal peduncle.
.. 53
Eye socket..
25.2 x 16.5
Interorbital ....
77
Eye to posterior nostril...
54
Asymmetrical:
Right.....
32
Left....
21
Interpostnasal...
.. 54.5
Dorsal spine...
.... 166
Pectoral spine....
... 177
Width of mouth....
88
Snout to dorsal....
... 320
Snout to anal.
... 570
Snout to pectoral....
.. 210
(The asymmetry in the following four measurements is due to accidental injury.)
Right maxillary barbel. ...
.. 94
Left maxillary barbel.....
... 115
Left inner mental barbel. ....
... 36
Left outer mental barbel......
55
Pectoral...
.I, 9
Dorsal ....
.I, 6
Ventrals....
.. 7
Anal....
9
Weight.....
..16 pounds.
Brownish black above, dirty white below. Fins and mouth black. Lateral scutes yellowish horn. Spines ivory
white.
FOOD: Flower buds, petals, seeds.
EYE: Sunk beneath surface of head. Iris 15 mm. in diameter. Purplish brown, flecked with yellowish white, the coloration
most prominent anteriorly and posteriorly. A narrow pupil rim, yellow, widest posteriorly, and sending downward
on lower side of the eye a single irregular line of whitish yellow, passing halfway through the iris. The Creoles
call this fish “Fork-snout," and claim that it is an adult Hemidoras carinatus, which is also known by that name.
This specimen was caught in a drift net in square B7 at Kartabo.
1 The following notes accompanied the large specimen taken by Dr. W. Beebe.
Specimen Number: T.R.S. 743. Skin only.

A REVIEW OF THE DORADIDÆ. //
335
D. I, 6; A. 11, scutes 3 + 18 to 23; head 3 to 3.75 in the length to the last scute;
eye 8 in the head, 4.5 in the snout, 3 in the interorbital in smallest, respectively 10.5,
5.5, 3.33 in the largest; from snout to dorsal fulcrum 2.4-2.66 in the length to end
of scutes. Bones of head striate in young and half grown, becoming striate granular;
premaxillaries subrhomboidal, about the size of eye. Teeth very feeble or none.
Dark brown, the fins black.
In the specimen from La Merced (Text-fig. 10), a small plate, similar to the
tympanic plates is interpolated between the first two hook-bearing ones and in a
line with the distant rudimentary ones. Scutes 3 +1 +1 + 17 or 18 (22 in the
largest).
32. Pseudodoras huberi (Steindachner).
Oxydoras (Rhinodoras) huberi Steindachner, Sitzb. K. Akad. Wiss. Wien, 1911, CXX, p. 324 (Rio Tocantins
at Cameta).
This species is known from the type, 400 mm. long, taken at Cameta by Dr.
Snethlage. It is now in the Vienna Museum.
Head 3.4; D. I, 6; A. 12; scutes 2 + 17; eye 8|1 in the head, 4 in snout, about 3
in interorbital. Bones of head striate granular; bristle-like teeth in moderate bands;
maxillary barbel to tip of humeral process; posterior nostril equidistant from the
anterior and the eye; pectoral spine longer than the head.
Black, with a lighter line along the middle of the back, from dorsal to end of
adipose, and brown to yellow markings on head and sides.
Genus XVIII. OXYDORAS Kner.
Oxydoras Kner, Sb. Ak. Wiss. Wien, XVII, 1855 (various species: D. stenopeltis Kner; carinatus C. and V.;
niger Kner, non C. and V.; lipophthalmus Kner; d'Orbignyi Kröyer).
Oxydoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 85 (reprint, p. 9).
Type, Oxydoras kneri Bleeker, based on Doras (Oxydoras) niger Kner, non Doras
niger Valenciennes.
The status of the name Oxydoras as restricted by Bleeker is given under Pseudo-
doras.
In 1863 Bleeker, p. 14, restricted the genus Oxydoras of Kner to specimens
supposedly belonging to Doras niger Valenciennes. But Kner's specimens did not
belong to Doras niger Val.
Later in the same year, p. 85, Bleeker restricted it by selecting as type the species
named niger by Kner but which was, in reality, a distinct genus and species named
kneri by Bleeker.
Similar to Pseudodoras, the number of lateral plates much larger, no tentacles on
roof of mouth.
Habitat: Paraguay Basin.

336
A REVIEW OF THE DORADIDÆ.
33. Oxydoras kneri Bleeker.
Plate 1, Fig. 15.
Doras (Oxydoras) niger Kner (non Doras niger Val.), Sb. Ak. Wiss. Wien, XVII, 1855, p. 146 (Cujaba).
Oxydoras kneri Bleeker, Nederl. Tijdsch. Dierk., I, pp. 12 and 14 (substitute name for Doras niger Kner non
Valenciennes); Eigenmann, Proc. Acad. Nat. Sci. Phila., 1903, p. 501 (Asuncion); Ribeiro, Peixes,
IV, 1911, p. 194; Fisher, Ann. Carnegie Mus., XI, 1917, p. 420 (Corumba).
Rhinodoras knerii Günther, Cat. Fish. Brit. Mus., V, 1864, p. 209.
The type, 15 inches long, is in the Vienna Museum. It has 34 lateral scutes,
those on the caudal peduncle deeper.
9840, one, 205 mm. to end of scutes. Asuncion Ternetz.
Head 3.5; D. I, 6; A. 12; scutes 3 + 34-40; eye 10 in the length of the head, 5.5
in the snout, 3 in interorbital; distance from tip of snout to dorsal fulcrum 2.66 in
the length to end of scutes; top of head and opercle striate-granular.
Genus XIX. RHINODORAS Bleeker.
Rhinodoras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 14.
Type, Doras (Oxydoras) d'Orbignyi Kröyer MS.
Eye medium, in middle of head; adipose fin prolonged forward as a keel; dorsal
spine strongly serrate, the serræ stronger on posterior margin; lateral scutes low,
about 30; caudal forked; caudal peduncle covered with plates (modified fulcra)
above and below; preorbital plates obscure; head subconical; fontanel continued as
an obscure groove to the dorsal. Air-bladders (Fig. 8, Plate 2) similar to those of
Pseudodoras niger but without indications of coca, the anterior bladder less depressed;
fontanel not divided, not continued as a groove. Mental barbels in two distinct
pairs.
34. Rhinodoras d'orbignyi (Kröyer) MS.
Plate 1, Fig. 18; Plate 26, Fig. 5.
Doras (Oxydoras) d'orbignyi (Kröyer) Kner, Sb. Ak. Wiss. Wien, XVII, 1855, p. 149, Pl. V, Fig. 9 (Rio
Plata).
Doras d'Orbignir Hyrtle, Denk. Ak. Wiss. Wien, XVI, 1859, p. 17 (vertebræ 6 + 4 + 21).
Rhinodoras orbignyi Bleeker, Nederl. Tijdsch. Dierk., 1, 1863, p. 84 (name); Günther, Cat. Fish. Brit. Mus.,
V, 1864, p. 209 (copied).
Oxydoras d'orbignyi Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 159; Occasional
Papers Cal. Acad. Sci., I, 1890, p. 249.
Doras nebulosus Eigenmann and Kennedy, Proc. Acad. Nat. Sci. Phila., July 1903, p. 500 (Asuncion);
Ribeiro, Peixes, IV, 1911, p. 213.
9837, I. U. M. one, 160 mm. (154 mm. at present), probably Asuncion. Carlos Ternetz.
Head 3.66; D. I, 6; A. 13; scutes 1 + 29 or 30, width at clavicle 1.15 in head,
about 4 in the length; eye 7.5 in the head, 3.5 in snout, 2 in interorbital; posterior

A REVIEW OF THE DORADIDÆ. /
337
nostril equidistant from anterior and lip; bones of head obscurely striate or granular;
mouth inferior, teeth strong, in short bands; maxillary barbel not reaching gill-
opening.
Sides and fins sharply clouded.
Genus XX. TRACHYDORAS Eigenmann, gen. nov.
Type, Trachydoras atripes Eigenmann.
Snout, preopercle and opercle granular; short and deep; coracoid process partly
or wholly granular; first lateral scute very large, connecting the humeral process
and the descending process of the dorsal plate; humeral process long and narrow,
more or less obliquely truncate; fontanel not continued as a groove; no foramen in
the dorsal buckler; snout short, anterior nostrils equidistant from tip of snout and
the posterior nostrils or nearer the former; mouth very small; teeth feeble, or none;
maxillary barbels just reaching gill-opening or shorter; adipose fin about half the
length of the anal, sometimes continued forward as a ridge; depth 3–4.5; one or more
pectoral pores.
Habitat: Paraguay and Amazon Basins.
KEY TO THE SPECIES OF TRACHYDORAS.1
a. Interopercle covered with skin; hooks of the lateral scutes along the line of the highest point in upper
margin of the humeral process; first scute not reaching the lower margin of the humeral process, posterior
margin of the humeral process obliquely emarginate.
b. Coracoid process much shorter than the humeral process, granular on part of its length; opercle, sub-
orbital line and preopercular line granular; depth 4 in the length to the end of lateral hooks, equal
to the length of the head; dorsal spine equal to head or head and width of humeral granulation;
pectoral spine longer; depth of caudal peduncle 4 in the head; eye 1.25 in interorbital, 1.66 in snout,
lateral plates .33 in the depth; posterior nostril nearer anterior nostril than eye; dorsal fulcrum
dark, middle caudal rays hyaline...
35. nattereri (Steindachner).
bb. Coracoid process a trifle longer than the humeral process, striate its entire length; suborbital line
covered with skin; opercle and preopercular line striate; depth 3.2 in the length, greater than head
and humeral granulations; dorsal spine equals length of head; pectoral spine considerably longer;
depth of caudal peduncle 3 in the head; eye 1.4 in interorbital, 3.1 in the head; lateral plates 33
of the depth; posterior nostril nearer eye than to anterior nostril; base of middle caudal rays
dusky......
36. paraguayensis (Eigenmann and Ward).
aa. Interopercle granular; hooks of the scutes above the line of the upper margin of humeral process; first
scute crescent-shaped, extending to the lower margin of the humeral process.
c. Dorsal spine equals head or a little shorter than head, about equal to the pectoral spine; depth of
caudal peduncle about 3.8 in the head; eye 1-1.25 in interorbital, equal to snout behind the anterior
nostrils; depth of lateral plates about 2.3 to 2.6 in the depth; posterior nostril much nearer eye than
to anterior nostril; scutes 35; maxillary barbel with many barblets........37. atripes Eigenmann.
1 D. microstomus, of which only small specimens, 52 mm. and shorter, have been taken, may belong here; in general appear-
ance, mouth, barbels, dorsal buckler, etc., it resembles the species of this group. The preopercle, operele, etc., are not granular,
but the preopercular edge extends as a ridge across the cheek. D. brevis also resembles this group.

338
A REVIEW OF THE DORADIDÆ.
cc. Dorsal spine equals head and a little more than width of the humeral granulation, about equal to
the pectoral spine; depth of lateral plates about half the depth; posterior nostril much nearer eye
than to anterior nostrils; D. I, 6; A. 13; scutes 33-34. Maxillary barbel with but one barblet;
all fins hyaline; eye equals interorbital..
...38. trachyparia (Boulenger).
35. Trachydoras nattereri (Steindachner).
Plate 18, Figs. 1 and 2; Plate 26, Figs. 2 and 3.
Oxydoras nattereri Steindachner, Flussf. Südam., II, 1881, p. 4, Pl. 2, Figs. 1-1a. (Teffé.)
Hemidoras nattereri Eigenmann and Eigenmann, Proc. Cal. Acad. Sci. (2), I, 1888, p. 158 (Coary; Jutahy;
Teffé); Occasional Papers Cal. Acad. Sci., I, 1890, p. 253; Fisher (part), Ann. Carnegie Mus., XI, 1917,
p. 421 (San Joaquin, Bolivia; Santarem; Maciél; Rio Guaporé).
15967, I. U. M. one, 130 mm. Iquitos. Morris. 1922.
Head 3.6; depth 3.5; D. I, 6; A. 14; scutes 3 + 32; eye 1.5 in snout, 3.5 in head,
1.25 in interorbital.
Snout blunt, occipital region roof-shaped; humeral process more finely striate
than in T. paraguayensis, the striation not more coarse toward the upper margin;
clavicular and coracoid granulation separated in front of the pectoral by an area
covered with skin; coracoid process reaching to middle of humeral process; maxillary
barbel with about 7 barblets; rudimentary scutes without a hook. Line of hooks
on a line with the uppermost point of the humeral process; a dark area about dorsal
fulcrum; a round dusky area at the base of each caudal lobe.
Anterior air-bladder with a bunch of finger-like cæca at the outer anterior
angles; posterior air-bladder very small, forked, the two branches like a pair of
horns, the points of the horns turned ventrad.
36. Trachydoras paraguayensis (Eigenmann and Ward).
Plate 1, Fig. 7; Plate 3, Fig. 8; Plate 18, Figs. 3 to 5; Plate 26, Fig. 1.
Hemidoras paraguayensis Eigenmann and Ward, Ann. Carnegie Mus., IV, 1907, p. 116, Pl. XXXIV, Fig. 1
(Corumba).
Hemidoras nattereri Fisher (in part), Ann. Carnegie Mus., XI, 1917, p. 421 (the specimens from San Joaquin,
Corumba and Villa Hays).
Specimens Examined.
10127, I. U. M., type, 87 mm. to end of last scute. Anisits.
Part of 7201, C. M. 5, 46–88 mm. to end of middle caudal rays. San Joaquin, Bolivia. Haseman, Sept.
1909.
7203, C. M. one, 93 mm. over all. Villa Hays. Haseman, April 13, 1909.
Head 3.33–3.7; depth 3.25 to 3.33 (3 in Villa Hays specimen); D. I, 6; A. 14;
scutes 3 + 29 or 30; eye 2 in snout, 4.5 in head, 2 in interorbital. Profile arched,
occipital region steeply roof-shaped.

A REVIEW OF THE DORADIDÆ.
A
339
General appearance of Doras brevis. Head granular above, except for a space
around and between the nostrils and the fontanel; fontanel not continued as a groove;
opercle and preopercle granular; suborbitals very narrow, granular; preorbital
granular; interopercle covered with skin; humeral process striate, a keel along its
lower edge, the ridges near the upper edge stronger than those in the center; posterior
edge emarginate, the upper and lower edges parallel; clavicle striate, united with the
striate part of the coracoid into a hook-shaped area in front and below the pectoral
spine; coracoid process striate, reaching as far as the humeral process; mouth narrow,
inferior, maxillary barbels reaching to below some part of the eye, with 3 to 6 barblets;
mental membrane narrow, the barbels papillose, without barblets. Teeth, if any,
not evident; rudimentary scutes minute but each with a hook; first scute very broad,
reaching from the dorsal plate to or near to the lower edge of the humeral process,
the part above the hook in the adult with numerous thorns, in several irregular
series; fewer in smaller; major hooks below the line of the hooks on the rudimentary
scutes of the tympanum, about on a line with the upper margin of the humeral
process; succeeding scutes much narrower and shorter, the series graduate to the last.
Dorsal spine shorter than pectoral spine, serrate in front to the upper third;
the serræ on the hinder margin with a few minute points; adipose well developed,
but usually shorter than the anal; anal more or less rounded; caudal very broad, the
fin but slightly emarginate when expanded; pectoral spine reaching just beyond
base of ventrals.
No markings; air-bladder heart-shaped; a small diverticulum branched or not
at the outer anterior corners; the second air-bladder minute, forked, about equal to
the diverticula.
37. Trachydoras atripes Eigenmann.
Plate 2, Fig. 5; Plate 18, Figs. 6 to 8; Plate 26, Fig. 4.
Specimens Examined.
15877, I. U. M., type, 60 mm. to end of lateral scutes, 72 mm. over all. Brook near R. Itaya, above Iquitos.
Allen. Sept. 1920.
7204, C. M. 2, the larger about 80 mm. Berlin, Rio Marmoré. Haseman. Sept. 15, 1909.
7201, C. M., 16006, I. U. M. 9, 73 to 103 mm. to end of middle caudal rays. San Joaquin, Bolivia. Haseman.
Sept. 1909.
Head 3.66 to 3.75; depth 4.25 to 5; D. I, 6; A. 14 to 17; scutes 3 + 34 or 35.
Eye 1.5 to 2 in snout; 3 to 3.5 in head; 1 to 1.33 in interorbital; head granular, much
as in paraguayensis; pit of the fontanel much longer, tapering at both ends, con-
tinued as a groove to the transverse groove on the occipital; profile not as steep as in
paraguayensis, the occipital region roof-shaped; suborbital bones stronger and more

340
A REVIEW OF THE DORADIDÆ.
a
prominently granular; nasal granular, its lower margin convex; interopercle and a
small angle of lower jaw granular; mouth small, inferior, without evident teeth;
maxillary barbel reaching to below the eye, with about 7 barblets; mental barbels
united by a broad membrane, without barblets; rudimentary scutes variable, the last
smallest, the two anterior linear or with the posterior half wider; coracoid processes
and a linear streak of the coracoid, forward of the lower edge of the pectoral spine,
granular; granular portion of the clavicle separated from the granular part of the
coracoid, covered with skin; angle of the mandible exposed, granular; coracoid process
considerably shorter than the humeral process; humeral process narrow, granular,
rather than striate; first scute wider below the hook than above it, extending from
the dorsal plate to a little below the humeral process, the surface with several sharp
pointed granules, many marginal spines; scutes regularly graduate, line of hooks
above on middle of the scutes, far above the upper margin of the humeral process;
dorsal spine little if any shorter than the pectoral spine; serræ on posterior margin
nearly as strong as on the anterior, the serræ antrorse but not as steeply so as on the
anterior margin; adipose smaller than the anal; caudal deeply forked; anal rounded,
its anterior half dusky.
Several branched cæca along the sides of the anterior air-bladder; posterior air-
bladder very short, with branched cæca on each side.
In the type the dorsal fulcrum and base of dorsal rays are dark; anterior half of
anal dark; pectoral dusky; middle caudal rays hyaline, a dusky band above and
below the hyaline.
38. Trachydoras trachyparia (Boulenger).
Oxydoras trachyparia Boulenger, Trans. Zool. Soc. London, XIV, 1898, p. 423, Pl. XL, Fig. 2 (Rio Jurua).
This species is known by the two types, 92 mm. long, in the British Museum.
Genus XXI. DORAS Lacépède.
Doras Lacépède, Hist. Nat. Poiss., V, 1803, p. 116; 12-mo., IX, 148 (Silurus carinatus Linnæus and Silurus
costatus Linnæus).
Doras Bleeker, Nederl. Tijdsch. Dierk., I, 1863, p. 13 (type carinatus).
Oxydoras Kner, Sb. Ak. Wiss. Wien, XVII, 1855 (various species, the first stenopeltis, others carinatus, niger
(non C. and V.), lipophthalmus, d'Orbigny, in the order named.
Hemidoras Bleeker, Ichthyol. Arch. Indici Siluri, 1858 (type stenopeltis). In 1862 Bleeker abandoned this
generic name, placing stenopeltis in the present Doras.
Hemidoras Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 250.
Oxydoras Günther, Cat. Fish. Brit. Mus., V, 1864, p. 206 (various species, the first one carinatus).
Doras Jordan, The Genera of Fishes, 1917, p. 65 (in listing the genera of Lacépède Jordan gives Silurus
carinatus L. as the type).
Moryrostoma Ribeiro, Arch. Mus. Nac. Rio de Janeiro, 1911, p. 192 (carinatus).
Type, Silurus carinatus Linnæus.

A REVIEW OF THE DORADIDÆ.
341
a
This is not the Doras of Cuvier and Valenciennes, Günther, the Eigenmanns
and authors, generally. Lacépède did not specifically state that he selected the
Silurus carinatus of Linnæus as the type of his Doras but placed it first. Neither did
Cuvier and Valenciennes specifically select a type for Doras but placed costatus first.
Their restriction is not more specific than is that of Lacépède.
Bleeker specifically selected carinatus as the type of Doras. This seems to
have been the first specific indication of the type. Jordan rules that carinatus being
the first species mentioned by Lacépède is the type of his genus.
Mandibulary barbels with a basal membrane, with or without barblets; maxillary
barbel with barblets; origin of the ventrals nearer the caudal than the snout; nuchal
buckler intact, without foramen, without a median groove continued from the
fontanel; the back between the dorsals without plates; lateral scutes moderate, the
first one connecting the dorsal plate, the first rib and the humeral process; coracoid
not granular; preopercle and interopercle covered with skin, not granular; a bony
stay from epiotic to the lower end of the process of the dorsal plate, and first scute;
adipose fin short, not continued as a keel.
Habitat: Rio Jauru to Guianas and Peru.
The air-bladders in this genus as accepted here differ considerably. In one type
the air-bladder is simple without diverticula, excepting that in the old there is de-
veloped a minute second air-bladder, carinatus, micropæus. In a number of other
species a second air-bladder is represented by two divergent recurved tubes. The
species having this type are brevis, punctatus, eigenmanni, and possibly the adult of
microstomus. In the third type it is heart-shaped with numerous radial diverticula.
They are especially prominent in front.
a
KEY TO THE SPECIES OF DORAS.
a. Eye equal to or less than interorbital.
b. First lateral scute unusually large, in contact with the coracoid process; teeth in both jaws; snout
covered with skin; eye 1.5 in the snout, 1.25 in the interorbital; maxillary barbels reaching beyond
base of pectoral; humeral process broad, rounded; a plate above and below the caudal peduncle;
dorsal and pectoral spines of equal length, the latter extending beyond base of ventrals; scutes 29–30.
Air-bladder simple, short, broad...
...39. fimbriatus Kner.
bb. First lateral scute not reaching coracoid process. Humeral process narrow.
c. Dorsal and pectoral spines equal, the former reaching beyond origin of adipose; adipose fin equals
anal; no teeth; origin of dorsal nearly midway between tip of snout and end of adipose; eye
equals interorbital. Scutes 29–30; unspotted; depth 3.4; maxillary barbel reaching to below eye;
mental barbels papillose; eye equals interorbital; air-bladder single, with very numerous di-
verticula and ending in two recurved horns...
.40. brevis Heckel.
cc. Dorsal spine shorter than pectoral spine, not reaching the adipose.

342
A REVIEW OF THE DORADIDÆ.
d. Maxillary barbel reaching base of pectoral; mental barbels without slender barblets, papillose;
snout considerably longer than the eye; scutes 29–30, the hook of the first one distinctly
above the line of the rest; the line of hooks on a level with the upper margin of the humeral
process; the rudimentary plates feeble, running below the middle of the pseudotympanum,
the last one with a thorn, much above the first of the lateral scutes. Eye 1.66 in interorbital;
center of opercle granular. Air-bladder ending in two recurved horns...41. punctatus Kner.
dd. Maxillary barbel reaching beyond base of pectoral; snout considerably longer than the eye;
scutes 26 to 29; the hooks of the lateral scutes just above the line of the upper margin of
the humeral process; eye 1.25 in interorbital. Mottled; mental barbels similar to the
maxillary, with many barblets. Air-bladder ending in two recurved horns.
42. eigenmanni (Boulenger).
aa. Eye greater than interorbital.
e. Lateral scutes 28–32, rarely 26.
f. Maxillary barbel not reaching pectoral; snout less than the eye (in young only?); line of scutes
distinctly above the level of the upper margin of the humeral process; the rudimentary plates
rather strong, running at or a little above the level of the rest. Scutes 26–32. Interorbital
less than vertical diameter of the eye, 1.5 in the longitudinal. Air-bladder in adult probably
ending in two recurved horns.
.43. microstomus (Eigenmann).
ee. Lateral scutes 33-35 (Valenciennes gives 36); orbit elongate; dorsal spine shorter than pectoral spine;
snout pointed; lateral plates narrow; interorbital much smaller than eye, 1.6–2 in the length of
the eye. Young with a single air-bladder; old with a small second bladder.
g. Scutes well developed...
44. carinatus (Linnæus).
gg. Anterior scutes minute; fins pigmented, dorsal dark, without a spot; snout long, subconical;
the mouth very large; 4-10 teeth on each side of upper jaw, 2-5 on each side of lower jaw;
no definite markings. Similar to carinatus..
.45. micropæus (Eigenmann).
eee. Lateral scutes 37–38, largest on the base of the caudal; orbit much elongate; dorsal spine longer than
pectoral spine; snout pointed, no teeth in upper jaw, lower jaw with minute teeth; barbels reaching
gill-opening; the mental barbels with barblets similar to those of the maxillary; membrane of the
mental barbels very wide; humeral process twice as long as high; interorbital equals vertical
diameter of eye. Air-bladder heart-shaped, no second bladder or cæcum, numerous marginal
diverticula, especially prominent in front...
...46. lipophthalmus Kner.
39. Doras fimbriatus Kner.
Doras fimbriatus Kner (Corydoras loricatus Heckel, MS.), Sb. Akad. Wiss. Wien, XVII, 1855, p. 134, Pl. III,
Fig. 5, dorsal view of head (Rio Guaporé).
Oxydoras fimbriatus Günther, Cat. Fish. Brit. Mus., V, 1864, p. 207 (copied).
Hemidoras fimbriatus Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 255.
Known from the types in the Vienna Museum.
40. Doras brevis Heckel.
Doras brevis 1 Heckel, MS. in Kner, Sb. Akad. Wiss. Wien, XVII, 1855, p. 138, PI. VI, Fig. 11 (Barra do
Rio Negro).
Known from the types in the Vienna Museum.
1 The specimens listed as brevis by Fisher, Ann. Carnegie Mus., XI, 1917, p. 421, do not belong to this species.

A REVIEW OF THE DORADIDÆ.
343
.
41. Doras punctatus Kner.
Plate 3, Fig. 5; Plate 21, Figs. 1 to 2; Text-fig. 12, E.
Doras punctatus Kner (Corydoras brevis Heckel, MS.), Sb. Akad. Wiss. Wien, VII, 1855, p. 136, PI. VI, Fig. 10
(Matto Grosso; Rio Guaporé).
Corydoras punctatus Hyrtle, Denk. Ak. Wiss. Wien, XVI, 1859, p. 17 (vertebræ 5 + 1 + 21).
Oxydoras punctatus Günther, Cat. Fish. Brit. Mus., V, 1864, copied.
Hemidoras punctatus Eigenmann and Eigenmann, Occasional Papers Cal. Acad. Sci., I, 1890, p. 255.
Hemidoras nattereri Fisher, Ann. Carnegie Mus., XI, 1917, p. 421 (part of No. 7201, San Joaquin, Bolivia).
Hemidoras brevis Fisher, 1.c., p. 421, part 7193 only (San Joaquin).
Specimens Examined.
7193, C. M., 96 mm. to end of middle caudal ray, and 7201, C. M. part 2, 69 to end of middle caudal ray.
San Joaquin, Bolivia. Sept. 5, 1909. Haseman.
15882, I. U. M. one, 118 mm. R. Paranapura, Yurimaguas. Allen. Nov. 1920.
15883, I. U. M. many, largest 99 mm. Lake Cashiboya. Allen. Aug. 1920.
The specimens enumerated above differ from those described as punctatus by
Kner in uniformly having longer maxillary barbels. Heckel had 17 specimens
between 3 and 5 inches long from the Rio Guaporé. In these he says that the maxil-
lary barbel uniformly fails to reach the gill-opening and has but 3 or 4 barblets.
Head 3.3 to 3.6; depth 3.9 to 4.2; D. I, 6; A. 12–14; scutes 2 +11+ 29; eye 1.7
in snout, 4 to 5 in the head, 1.6 to 1.75 in the interorbital. Head broad, narrowed
to a sharp snout; occiput roofed; mouth subterminal, with teeth in two small patches
in each jaw; opercle with a granular patch, cheeks and snout otherwise covered with
skin; head above, behind posterior nostril finely granular-striate; fontanel elongate,
ending abruptly above the middle of the eye, not continued as a groove; scapular
region broad, the humeral process narrow, grooved and striate but not as deeply as
in eigenmanni; its upper margin emarginate, its lower margin keeled; coracoid process
as long as the humeral process; scutes in tympanum imbedded, the last one with a hook
similar, but smaller than the hooks of the lateral series.
An inconspicuous spot near the center of the dorsal; an obscure dusky band
along the middle of the back, from the dorsal to the caudal; a very obscure dusky
band across the occipital and continued on the sides just above the hooks of the
lateral line and above the center of the upper caudal lobe; a similar band through
the center of the lower caudal lobe. In 15882, the bands are obsolete on the back and
sides, but well marked on the caudal; the sides and the head in this specimen have
rather sharp, small, dark spots. Posterior air-bladder forked.
1 A rudimentary scute bearing a hook some distance above the hooks of the fully developed series.
a
23

344
A REVIEW OF THE DORADIDÆ. .
42. Doras eigenmanni (Boulenger).
Pate 21, Figs. 3 and 4.
Oxydoras eigenmanni Boulenger, Proc. Zool. Soc. London, 1895, p. 524; Trans. Zool. Soc. London, XIV,
1896, p. 28, Pl. IV, Fig. 3 (Descalvados, Matto Grosso); Eigenmann, McAtee and Ward, Ann.
Carnegie Mus., IV, 1907, 116 (Corumba).
Hemidoras brevis Fisher (part), Ann. Carnegie Mus., XI, 1917, p. 421 (Rio Jaurú).
Specimens Examined.
10140, I. U. M. 5, largest 107 mm. to end of middle caudal rays. Corumba, Paraguay. Anisits.
16190, I. U. M. 2, 78 and 85 mm. Santarem market. Carl Ternetz.
7190, C. M. 1, 95 mm. to end of middle caudal rays. Santarem. Dec. 15, 1909. Haseman.
7191, C. M. 1, 80 mm. to end of middle caudal rays. Caceres. May 26, 1909. Haseman.
7192, C. M. 1, 92 mm. Maciel, Rio Guaporé. Aug. 3, 1909. Haseman.
7194, C. M. 3, 75–90 mm. to end of last scute. Rio Jaurú. June 4, 1909. Haseman.
These are some of the specimens identified by Fisher as brevis.
Head 3.75 to 4; depth about equal to the head; D. I, 6; A. 12 to 13; scutes 28
to 29 (rarely 26). Eye 2.5 in snout, 4.75 in head, 1.75 in interorbital. Head broad,
narrowed to a sharp snout; occiput roofed; mouth subterminal, with two small
patches of comparatively strong teeth in both jaws; cheeks and snout in front of the
posterior nostrils covered with skin, head above granular-striate from posterior
nostril back; fontanel oval, ending abruptly over the pupil, not continued as a groove;
scapular region broad, the humeral process deeply grooved and with prominent
ridges, leaving a median, terminal depression free from keels; coracoid process heavy,
about as long as the humeral process, finely striate from near the suture to the tip;
scutes in the tympanum imbedded, scarcely evident; one scute only in contact with
the dorsal plate; the series of hooks in a line just above upper margin of the humeral
process, the hook of the first scute scarcely above the line of the rest; the scutes
between a third and a fourth of the height, the median spine of the last not much
smaller than those immediately in front of it; several marginal points above and
below the median hook.
Maxillary barbel extending beyond the base of the pectoral spine; with about a
dozen or more long, slender barblets in an alternating row on the ventral surface and
outer edge; mental barbels and barblets (5–7) similar to the maxillary; basal mem-
brane of mental barbels insignificant, the mental barbels reaching beyond the gill-
opening, the outer considerably longer than the inner. Dorsal spine strongly serrate
on its anterior margin, less so on its posterior edge, its sides deeply grooved and
ridged; pectoral spine usually extending beyond base of ventrals; origin of ventrals
midway between snout and end of last scute, or nearer the later point; caudal forked;

A REVIEW OF THE DORADIDÆ.
345
anal rounded, adipose about as long as the anal. Everywhere mottled, light below;
fins spotted.
This species resembles punctatus as figured by Heckel, in which, however, the
first thorn of the lateral series lies higher than the rest and the maxillary barbels
never reach the gill-opening and have but 3 to 4 barblets.
43. Doras microstomus (Eigenmann).
Hemidoras microstomus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, p. 394 (name only);
Mem. Carnegie Mus., V, 1912, p. 193, Pl. XVIII, Fig. 2 (Rockstone and Crab Falls, on the Essequibo,
British Guiana); Steindachner, Fluss. Südam., V, 1915, p. 57 (Rio Branco at Boa Vista and Serra
Grande; Rio Surumu).
Specimens Examined.
12039, I. U. M. Rockstone. Eigenmann.
12040, I. U. M. Crab Falls. Eigenmann.
Air-bladder broad, simple; an incipient double diverticulum at the end indicates
that a forked double cæcum develops with age.
44. Doras carinatus (Linnæus).
Plate 1, Figs. 8, 9, 10; Plate 2, Fig. 6; Plate 20, Figs. 1 and 2; Plate 23, Fig. 4;
Plate 27, Fig. 8.
Silurus carinatus Linnæus, Syst. Nat., ed. 12, 1, 1766, p. 504; Bloch and Schneider, Syst. Ichth., 1801, p. 108.
Doras carinatus Lacépède, Hist. Nat. Poiss., V, 1803, p. 116 (Surinam); Cuvier and Valenciennes, Hist. Nat.
Poiss., XV, 1840, p. 288, Pl. 442 (Cayenne); Müller and Troschel, in Schomburgk, Reisen, III, 1848,
p. 629 (Essequibo); Bleeker, Ichth. Arch. Ind. Prodr., I, 1858, p. 54; Nederl. Tijdsch. Dierk., I, 1863,
p. 13 (name only); Silures de Suriname, 1864, p. 31 (Surinam).
Doras (Oxydoras) carinatus Kner, Sb. Akad. Wiss. Wien, XVII, 1855, p. 144 (Surinam).
Oxydoras carinatus Günther, Catalogue, V, 1864, p. 206 (Surinam; Essequibo River); Vaillant, Bull. Soc.
Philom. (7), IV, 1880, p. 154 (Calderon).
Hemidoras carinatus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci. (2), I, 1888, p. 158; Occasional
Papers Cal. Acad. Sci., I, 1890, p. 258; Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910,
p. 394; Mem. Carnegie Mus., V, 1912, p. 194.
Doras oxyrhynchus Valenciennes, in Humboldt, Rec. d'Obs. Zool. et Anat. Comp., II, 1833, p. 184 (Tu-
matumari on the Potaro; Bartica; Rockstone; Crab Falls; Georgetown market).
Specimens Examined.
12026, I. U. M. Rockstone. Eigenmann.
12027, I. U. M. Georgetown. Eigenmann.
12028, I. U. M. Crab Falls. Eigenmann,

346
A REVIEW OF THE DORADIDÆ.
45. Doras micropoeus (Eigenmann).
Plate 1, Fig. 17; Plate 2, Fig. 1; Plate 20, Fig. 3; Plate 24, Figs. 1 and 2;
Plate 27, Fig. 5.
Hemidoras micropæus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, p. 394 (na only);
Mem. Carnegie Mus., V, 1912, p. 195 (British Guiana at Lama Stop-Off and Wismar on the Demerara
River).
12029, I. U. M. Lama Stop-Off. Eigenmann.
46. Doras lipophthalmus Kner.
Doras (Oxydoras) lipophthalmus Kner (Corydoras ophthalmus Heckel, MS.), Sb. Akad. Wiss. Wien, XVII,
1855, p. 147, Pl. 5, Fig. 8 (Rio Negro).
Oxydoras lipophthalmus Günther, Cat. Fish. Brit. Mus., V, 1864, p. 208 (River Capin).
Hemidoras lipophthalmus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 158; Occa-
sional Papers Cal. Acad. Sci., I, 1890, p. 255.
This species is known from the types, 4 specimens 7] inches long and a specimen
in the British Museum.
Genus XXII. HEMIDORAS Bleeker.
Hemidoras Bleeker, Ichthyol. Arch. Indici Siluri, 1858.
Type, Hemidoras (Oxydoras) stenopeltis Kner.
Bleeker who created the genus Hemidoras in 1858 abandoned it in 1862, placing
its type in the present genus Doras.
Snout long, subconical, smooth; lateral plates well developed along the entire
line; depth more than one fifth, rarely less than one fifth of the length; humeral
process longer than deep; mouth small; ventrals behind the middle of the body;
maxillary barbel with many barblets, mental barbels united by a basal membrane,
fringed with a double row of barblets.
A series of plates along the middle of the back between the dorsals and sometimes
between the anus and anal; a small foramen in the dorsal buckler; fontanel continued
as a groove.
The air-bladder in morrisi is prolonged in a short diverticulum to a point. Nu-
merous branched tufts of diverticula around the entire margins.
a
KEY TO THE SPECIES OF HEMIDORAS.
a. Premaxillaries and dentaries without teeth or with a small patch of teeth; maxillary barbel extending
beyond base of pectoral; scutes 32 to 37. Eye 1.5 in snout, 3-3.4 in head, greater than interorbital;
D. I, 6....
..47. stenopeltis (Heckel).
aa. Eye (orbit) 4.25–5 in head, 2.25–2.75 in snout, 0.8 in interorbital; scutes 33–34.
48. morrisi Eigenmann.

A REVIEW OF THE DORADIDÆ.
347
47. Hemidoras stenopeltis (Heckel).
Corydoras stenopeltis Heckel, MS. as Doras (Oxydoras) stenopeltis in Kner, Sb. K. Akad. Wiss. Wien, XVII,
1855, p. 142, Pl. IV, Fig. 7 (Rio Negro).
Oxydoras stenopeltis Günther, Cat. Fish. Brit. Mus., V, 1864, p. 208 (copied).
Hemidoras stenopeltis Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 158; Occasional
Papers Cal. Acad. Sci., I, 1890, p. 256 (Manaos, Rio Negro; Hyavary; Manacapuru; Teffé; Obidos;
Tabatinga); Fisher, Ann. Carnegie Mus., XI, 1917, p. 422 (Rio Madeira near San Antonio).
7186, C. M. 2, 107 and 132 mm. San Antonio. Nov. 3, 1909. Haseman.
15907, I. U. M. 1, 80 mm. Pebas, Peru.
Pebas, Peru. J. B. Steere.
Head 3.8 to 4; depth 5.2 to 5.33; D. I, 6; A. 13 to 15 (including rudimentary
rays).
Eye 1.5 to 1.6 in snout, 3 to 3.4 in the head, about 0.75 in interorbital. Cheeks
and snout without granulations; fontanel reaching the posterior edge of the pupil;
skull striate; snout curved; mouth inferior; no teeth, or small patches of very minute
teeth; anterior nostrils equidistant from tip of snout and eye; mental barbels with
about 9 barblets, the basal half of which are scale-like, the posterior slender; maxillary
barbel reaching beyond base of pectoral, with about 15 barblets along its outer edge,
none on inner edge or surface. Three scutes on the tympanum, the first with down-
ward projecting branch; 32 to 37 hook-bearing scutes, deepest in front, graduate to
the last; numerous marginal spines both above and below the median hook; caudal
peduncle with inconspicuous fulcra covering about half its length above and below;
about ten plates along the back from the tip of the last dorsal ray, graduate to the
adipose; dorsal spine as long as, or longer than, the pectoral spine, which reaches the
ventrals; adipose fin nearly as long as the anal; caudal deeply forked; origin of ventrals
little nearer snout than end of middle caudal rays; humeral process without distinct
keel, its lower edge not parallel with the pectoral spine, the entire process below the
line of the hooks of the lateral scutes.
A dark area about the dorsal fulcrum; tip of dorsal spine and of first ray black;
a pair of dusky streaks on the caudal.
48. Hemidoras morrisi Eigenmann, spec. nov.
Plate 27, Fig. 3.
15962, I. U. M. 2, 77 and 147 mm., the latter the type. Iquitos. Morris.
Description of the Type: Head 3.2; depth about 6; D. I, 6; A. 14; scutes 33 or 34;
distance between snout and end of dorsal plate 23 in the length; ventrals nearer tip
of middle caudal rays than snout.
Slender, lateral scutes all well developed, about half the depth; the anterior
ones with several (up to 6 or 7) marginal spines both above and below the median

348
A REVIEW OF THE DORADIDÆ.
hook; about 14 very small scutes in front of the adipose; numerous, narrow, laminate
caudal fulcra; a well-defined groove from the fontanel to the dorsal; snout smooth;
suborbital line granular, upper posterior part of opercle granular, the rest of the
opercle striate; two large granular scutes on the pseudotympanum; humeral spine
slender, its dorsal margin emarginate; mouth without teeth (with up to 6 teeth on a
side in each jaw in the paratype); snout long, slender; posterior nostril about equi-
distant from snout and eye; eye (orbit) slightly elongate, šof the snout, ž in the
interorbital, 4.33 in the head; maxillary barbel reaching about to base of pectoral;
mental barbels short, their connecting membrane narrow; dorsal spine about equal
to snout and eye (longer in paratype, equal to pectoral spine); adipose fin not quite
as long as anal; pectoral spine almost equal to head, extending past origin of ventrals;
a large pectoral pore. No prominent markings.
7
9
Genus XXIII. OPSODORAS Eigenmann, gen. nov.
Type, Opsodoras orthacanthus Eigenmann, spec. nov.
Maxillary barbels with barblets, mental barbels with a double series of papils
or barblets; a foramen on each side of the nuchal shield; no plates along the back;
origin of the ventrals nearer caudal than snout; lateral scutes well developed, suc-
cessive ones in contact, or the anterior ones minute, not in contact.
Air-bladder single, blunt or pointed behind, with fine, thread-like, branched
diverticula, at least in hemipeltis, parallelus, humeralis and orthacanthus. In leporhinus
of which only young were examined the air-bladder is without diverticula and ends
in a blunt double point.
a
Habitat: Amazon and Guianas.
KEY TO THE SPECIES OF OPSODORAS.
a. Fontanel not continued as a groove to the dorsal plate; mental barbels papillose; well-developed teeth
on the lower jaw; air-bladder profusely provided with thread-like cæca.
6. Anterior scutes minute, successive ones not in contact with each other; interorbital convex; groove
from fontanel reaching beyond eye; snout conical; its width in front of the eye little more than
its depth; adipose eyelid prominent; maxillary barbel reaching to below posterior border of eye; a
dark streak below the lower margin of eye. ...
.49. hemipeltis Eigenmann.
bb. Depth of scutes about one half the diameter of the eye; foramen large, triangular; interorbital flat;
groove of the fontanel truncate behind; snout depressed, much wider in front of eye than high;
depth of humeral process at its widest less than the orbit; maxillary barbel reaching beyond the
eye; scutes 0 + 32; edge and upper surface of the air-bladder most profusely supplied with cæca;
pectoral spines not reaching ventrals.....
...50. parallelus Eigenmann.
bbb. Depth of scutes at least equal to the diameter of the eye, frequently much higher; foramen moderate,
oval; groove of the fontanel pointed behind; depth of the humeral process at its widest equal to
the orbit; scutes 3 + 31 or 32; air-bladders with numerous cæca; pectoral spines reaching ventrals.
51. humeralis (Kner).

A A REVIEW OF THE DORADIDÆ.
349
a
aa. Fontanel continued to the dorsal plate as a well-defined, narrow groove.
c. Keel of humeral process with its point continuous with the line of the hooks of the lateral scutes;
scutes 30 to 31; eye 1 to 2 in interorbital; snout long, the distance between the nostrils about equal
to the distance between the posterior and the eye; anterior nostril about equidistant from lip and
the eye; mental barbels with a double row of barblets; foramen minute.
52. orthacanthus Eigenmann.
cc. Keel and point of the humeral process below the line of hooks of the lateral scutes.
d. A black spot on the base of the dorsal and another narrow oblique spot on the base of each caudal
lobe. *
e. The spots well defined; the lateral scutes about equal to the vertical diameter of the eye;
maxillary barbel reaching the axil, with 3 short graduate barblets on the lower surface at inner
edge of the barbel, near its base, with about 20 slender, graduate barblets along its outer
edge; scutes 31-32.....
..53. trimaculatus (Boulenger).
ee. Color markings more diffuse; the scutes with a light band, continued to end of middle caudal
rays, dark above and below the band, the dark best marked on caudal; lateral scutes less than
half the vertical diameter of the eye, 1.66 in its longitudinal; maxillary barbel reaching to
pectoral spine, with about 11 flat, fringed barblets along its outer edge; mental barbels with
numerous papils; each ramus of the lower jaw with about 5 brown-tipped teeth, those of
the two rami forming a median group; lateral plates 33 to 35.
54. leporhinus (Eigenmann).
dd. No distinct markings.
f. Lateral scutes 29 to 35.
g. Lower edge of humeral process convex; eye about equal to interorbital.
h. Lateral scutes 35; eye a little greater than interorbital; mental barbels with barblets;
the rudimentary scutes large; humeral process long, slender, three times as long as
deep; depth of lateral scutes greater than orbit.......55. boulengeri (Steindachner).
hh. Lateral scutes 29 or 30, interorbital about equal to the eye; the rudimentary scutes
minute; humeral process twice as long as deep; depth of scutes less than orbit.
56. stübeli (Steindachner).
gg. Lower edge of humeral process straight; interorbital 1.3 in eye. Lateral scutes 32 to 35;
dorsal spine equals pectoral spine, the latter reaching beyond the origin of the ventrals;
eye about one fourth larger than the interorbital; scutes 34...57. morei (Steindachner).
ff. Lateral scutes 38 to 40; eye three tenths larger than the interorbital.
58. steindachneri Eigenmann.
49. Opsodoras hemipeltis Eigenmann, spec. nov.
Plate 19, Fig. 2; Plate 24, Fig. 6.
15879, I. U. M., type, 143 mm. Rio Ucayali at Contamana. Allen. Sept. 1920.
Head 3.5; depth at occiput 6, at dorsal 5, at caudal peduncle 15.5; D. I, 6; A. 11;
scutes about 33.
Sub-spindle shaped, the width everywhere approximating the depth; snout
conical, opercles flush with the shoulders; interorbital convex; fontanel not continued
* A new species allied to trimaculatus and leporhinus has been received; see no. 53a.

350
A REVIEW OF THE DORADIDÆ.
a
as a groove, eye in center of the head, 1.5 in interorbital, 4 in the head; profile gently
arched to the posterior nostrils, rapidly descending from the posterior nostrils forward;
occipital striate, head otherwise smooth; snout small, width of the lower jaws 2 in
the eye; barbels slender, basal membrane connecting the barbels small; the mental
barbels simple, the maxillary barbels with a series of barblets along their outer edge,
reaching to below posterior part of eye; width of isthmus equals snout; humeral
process striate, triangular, its length equals snout, its height 1.5 in the eye; first
eleven scutes rudimentary but increasing slightly, those above anal graduate, the
most fully developed ones above end of anal; dorsal spine equals head behind posterior
nostril, basal half of its anterior edge rough, its entire posterior edge serrate; adipose
fin minute, half the length of the anal; caudal forked, its lobes equal; head behind
posterior nostrils; anal short, truncate, its base less than snout; ventrals a little
longer than snout, reaching half way to middle of anal; pectoral spines broken, the
first ray equals head less half the snout; dusky above the lateral scutes, light below;
lower border of orbit dark, no other markings.
Air-bladder prolonged, with many thin, branched diverticula.
1922.
50. Opsodoras parallelus Eigenmann, spec. nov.
Plate 19, Fig. 3; Plate 23, Fig. 3.
15964, I. U. M., type, 151 mm. Iquitos. Morris.
This species is evidently closely related, if distinct from 0. hemipeltis. The
lateral scutes are much better developed, the top of the head and nasal bones are
granular, the opercle is striate; teeth of the lower jaw well developed but very fine,
in two patches; mental barbels papillose, the maxillary barbels reaching to below
middle of opercle; pectoral spines equal to the head behind the anterior nostrils, with
small serræ on both surfaces to near the tip.
Profile less arched; interorbital flat.
Air-bladder prolonged into a point; with many thin, branched diverticula.
51. Opsodoras humeralis (Kner).
Plate 1, Fig. 6; Plate 2, Fig. 4; Plate 18, Figs. 9 and 10; Plate 19, Fig. 1.
Doras humeralis (Corydoras humeralis Heckel, MS.) Kner, Sb. Akad. Wiss. Wien, XVII, 1855, p. 140, P. IV,
Fig. 6 (Barra do Rio Negro).
Oxydoras humeralis Günther, Cat. Fish. Brit. Mus., V, 1864, p. 206.
Hemidoras humeral s Eigenmann and Eigenmann, 1.c., 1888, p. 158; 1890, p. 258.
Hitherto known only from the types.

A REVIEW OF THE DORADIDÆ.
351
Specimens Examined.
15880, I. U. M. one, about 154 mm. Rio Ucayali at Contamana. Allen. July 1920.
15881, I. U. M. 22, largest 145 mm. Specimen drawn 138 mm. long. Iquitos. Allen.
7189, C. M. 4, largest 122 mm. San Joaquin, Bolivia. Sept. 5 and 6, 1909. Haseman.
Resembling brevis, leporhinus and microstomus.
Head 3.5, depth at occiput 4.5–4.8; at dorsal spine 4–5; at caudal peduncle
14.5–15.5; D. I, 6; A. 10 to 12; scutes 0 to 4 + 29 to 32.
Heavy in front of dorsal; depth distinctly greater than the width except at
caudal peduncle; snout subconical; opercles flush with the shoulders; interorbital
slightly convex, fontanel not continued as a groove on the occipital; profile gently
arched to posterior nostrils; the snout rapidly pointed in front of this point; distance
between snout and anterior nostril about equal to the distance between the posterior
nostril and eye, less than the distance between the anterior and posterior nostrils;
top of head granular to posterior nostrils; opercle striate, head otherwise smooth;
width of lower jaw a little more than half the length of the eyes; upper jaw with rarely
a tooth; lower jaw with one or two series of teeth, those of the outer series larger,
about 10 on each side; humeral process rough, very wide, its greatest width equal
to the eye, 0.4-3 in its length, the margin from the point to its upper anterior angle
either convex or with a distinct angle; mental barbels papillose, the maxillary barbel
reaching to some point below the eye, with a lobe at its base on the inner margin,
with about 7 slender barblets along its outer margin; scutes all well developed,
graduated from the first back, about 0.4 in the height, with a median spine and a
serrated margin; dorsal spine a little longer or shorter than the head; basal six tenths
of anterior margin serrate, its entire posterior edge serrate; adipose fin half the
length of the anal; caudal lobes about equal to the head behind the anterior nostrils;
anal short, truncate, its base less than the snout; ventrals about equal to the snout;
pectoral spines extending beyond origin of the ventrals; pectoral spine much longer
than the dorsal spine, about equal to its distance from the snout to the upper angle
of the humeral process; coracoid process covered.
Ashen above, light below; shadowy bands on the caudal lobes.
Air-bladder rounded behind, with many thin, branched marginal diverticula.
a
a
52. Opsodoras orthacanthus Eigenmann, spec. nov.
Plate 22, Fig. 3; Plate 23, Fig. 2.
Specimens Examined.
15884, I. U. M. 1, 133 mm. type. Iquitos. Morris. 1922.
15885, I. U. M. 4, 69–82 mm. Lake Cashiboya. Allen. Aug. 1920.
15886, I. U. M. 3, 77–98 mm. Mouth of Rio Pacaya. Allen. 1920.

352
A REVIEW OF THE DORADIDÆ.
a
Distinguished by the fact that the hooks on the lateral plates form a continuous,
straight or nearly straight line with the ridge and tip of the humeral process.
Head 3.25; depth 5; D. I, 6; A. 12; scutes 30–31. Eye 2.33-2.66 in snout, 4.5–5
in the head, 1-2 in interorbital; snout acutely pointed; no teeth, width of lower jaw
about 1.5 in the eye.
Width at the first dorsal and first anal rays equal to the depth at the same points;
head wider than deep; head granular to the posterior nostrils; the foramen between
dorsal plate and occipital minute; upper part of opercle granular; mental barbels
with barblets; snout and cheeks covered with skin; humeral process triangular, the
lower edge sloping, with a distinct ridge parallel with the depressed pectoral spine,
its tip beyond the middle of the pectoral spine; coracoid process covered, reaching a
little beyond middle of humeral process; dorsal spine serrate in front, roughened
behind, about equal to snout and eye; pectoral spine equals length of head, reaching
beyond origin of ventrals; base of adipose almost equal to base of anal; caudal forked,
the upper lobe about equal to snout and eye; anal and ventrals rounded; two rudi-
mentary scutes at beginning of lateral line at a much higher level than the fully
developed ones; lateral scutes equally developed, the hooks under the dorsal much
below the middle, behind the dorsal in the middle of the sides; each scute with a
median hook and marginal serræ; sides above the hooks dusky, below them light,
parallel dusky shades on the caudal lobes.
Air-bladder with many marginal diverticula.
53. Opsodoras trimaculatus (Boulenger).
Oxydoras trimaculatus Boulenger, Trans. Zool. Soc., XIV, 1898, p. 422, Pl. XL, Fig. 1 (Rio Jurua, 62 mm.).
Leptodoras trimaculatus Fowler, Proc. Acad. Nat. Sci. Phila., 1914, p. 264, Fig. 14 (Rupununi River, British
Guiana, 77 mm.).
Hemidoras lipophthalmus (non Kner) Fisher, Ann. Carnegie Mus., XI, 1917, p. 421 (Santarem, 58 mm.).
Fowler proposed his L. trimaculatus as a new species but it is very probably
identical with the 0. trimaculatus of Boulenger.
7200, C. M. one, 58 mm. to end of middle caudal rays. Santarem. Haseman.
Head 3.66 in the length, caudal depth 4.6; D. I, 6; A. 14; scutes 2 or 3 + 30;
eye 1 in snout, 2.8 in head, 0.5 in interorbital.
Snout very narrow, sharply decurved, pointed; mouth inferior, below the level
of the eye, teeth very few, minute; cheeks and snout covered with skin, the skull
striate, granular; a well-developed foramen on each side of the occiput; anterior
nostril equidistant from snout and eye; fontanel very long, a bridge behind the pupil,
continued as a groove to the dorsal plate; mental barbels very short, covered with

A REVIEW OF THE DORADIDÆ.
353
.
a
wart-like papillæ; maxillary barbels reaching to some point on the base of the pectoral.
four short graduate barblets on its inner lower surface, about 20 longer, more slender
barblets along its outer edge; anterior scutes about 0.4 of the height, with about 4
marginal lobes below and one above the median hook; caudal fulcra numerous,
laminate; lower edge of humeral process without a keel, its point below the line of
the hooks; dorsal spine shorter than pectoral spine, longer than head; pectoral spine
extending beyond the base of the ventrals; origin of ventrals a little nearer end of
middle caudal rays than the snout; caudal deeply forked; a triangular black spot
on base of anterior half of the dorsal, converging black stripes on base of caudal
lobes.
This specimen is undoubtedly young. Its head is striate. It differs from the
trimaculatus of Boulenger (62 mm.) in that the latter does not have the fontanel
continued as a groove. It is possible that both are juvenile forms of a species re-
sembling 0. steindachneri.
53a. Opsodoras ternetzi Eigenmann, spec. nov.
16173, I. U. M. one specimen, type 128 mm. Tapajos at Santarem. 1924. Carl Ternetz.
Head 4; depth 4.75; D. I, 6; A. 10; plates 4 + 33.
Ventral profile very slightly curved; dorsal profile very convex to the dorsal,
thence nearly straight but downward to the caudal peduncle. Snout conical; depth
at dorsal fulcrum equal to length of snout and eye; eye 3.33 in head; eye behind
middle of head; interocular 2 in length of eye; snout decurved; maxillary reaching
axil, with about 17 barblets; fontanel continued to the dorsal plate; dorsal spine
equal to length of head, with numerous spines, the antrorse spines extending the
basal sixth of the spines, the retrorse spines extending about the basal six-sevenths of
the posterior face of the spine; pectoral spine about equal to the dorsal spine, the hooks
extending along the entire spine; caudal distinctly forked; depth of lateral scutes
above the ventrals about 2 in length of eye. Upper surface of tip of snout dark;
dorsal fulcrum dark; a narrow dusky streak on middle of back; a dark band above
the scutes, a dusky streak below the scutes; a pair of dusky bands above and below
the middle caudal rays. Lower margin and keel of humeral spine far below the line
of the lateral spines; the small spines in the tympanum above the lateral hooks.
Numerous and conspicuous mucous pores. Teeth not evident.
Air-bladder with irregular series of partly branched, lateral diverticula, a bunch
of diverticula at middle of sides and another at the outer, anterior angle of the blad-
der; no posterior air-bladder, but an irregular protuberance from which diverticula
radiate.

354
A REVIEW OF THE DORADIDÆ.
54. Opsodoras leporhinus (Eigenmann).
Hemidoras leporhinus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, p. 394 (name only;)
Mem. Carnegie Mus., V, 1912, p. 195, Pl. XIX, Fig. 1 (British Guiana at Tumatumari, Potaro River,
and Crab Falls, Essequibo River); Steindachner, Flussf. Südam., V, 1815, p. 58, Pl. IX, Figs. 1-4
(Rio Surumu; Rio Branco at Serra Grande and Boa Vista).
I. U. M. 12021, 2 young, about 52 mm. Crab Falls. Eigenmann.
55. Opsodoras boulengeri (Steindachner).
Hemidoras (Leptodoras) boulengeri Steindachner, Flussf. Südam., V, 1915, p. 63, Pl. VIII, Figs. 1-3 (mouth
of Rio Negro).
Known from the types.
56. Opsodoras stübeli (Steindachner).
Plate 27, Figs. 6 and 7.
Oxydoras stübeli Steindachner, Flussf. Südam., IV, 1882, p. 5, Pl. III, Figs. 1-16 (Rio Huallaga).
Hemidoras stübeli Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 158; Occasional
Papers Cal. Acad. Sci., I, 1890, p. 257.
Known from the types, three specimens 80-120 mm. long, in the Vienna Museum.
57. Opsodoras morei (Steindachner).
Plate 27, Figs. 1 and 2.
Oxydoras morei Steindachner, Flussf. Südam., II, 1881, p. 6, Pl. I, Figs. 2–2a (Rio Negro).
Hemidoras morei Eigenmann and Eigenmann, 1.c., 1888, p. 158; 1890, p. 257.
Known from the type, a specimen 125 mm. long, in the Vienna Museum.
58. Opsodoras steindachneri Eigenmann, spec. nov.
Hemidoras carinatus non Linnæus, Steindachner, Flussf. Südam., V, 1915, p. 55 (mouth of Rio Negro).
Based on a specimen 197 mm. to base of caudal, 235 mm. over all, in the Vienna
Museum.
Head about 26; depth 43; scutes 38–40; D. I, 6; A. 3, 9.
Foramen tolerably large; snout long, compressed; maxillary barbels not quite
reaching pectoral; mental barbels connected for half their length by membrane;
mouth inferior, a few feeble teeth in each jaw; lateral plates low, of about uniform
height to the middle of the body, then increasing in height to the middle of the caudal
peduncle; depth about 4ş; distance between snout and dorsal 2.33 in the length;
humeral process oblique, with convex posterior margin, 3 times as long as high;
distance between tip of snout and ventrals 1} in the length.
Width of head 2 in its length; length of eye 4 in the length of the head, 2.35 in
snout; height of eye equals interorbital, 5.66 in length of head; dorsal spine 16,

A REVIEW OF THE DORADIDÆ.
355
pectoral 1%, ventral 1.8, depth of caudal peduncle 6, its length 2.4 in the length of
the head.
The above is an abstract of Steindachner's description of Doras carinatus men-
tioned above. But Doras carinatus does not have a foramen except in the very young.
It is therefore very probable that the specimen recorded by Steindachner, which has a
large foramen, is not specifically or even generically identical with those recorded by
Eigenmann from Guiana. Guiana specimens have about 33 scutes. Steindachner
records 38 on one side and 40 on the other of his specimen. This makes Steindachner's
identification doubly doubtful.
Genus XXIV. HASSAR Eigenmann and Eigenmann.
Hassar Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 158.
Type, Oxydoras orestis Steindachner.
Snout, preopercle, and interopercle covered with skin. Anterior scutes of the
lateral line very small; humeral process blunt, rounded, about twice as long as broad,
extending past middle of pectoral spine, without keel; pectoral spine barely reaching
ventrals or shorter; mouth large; a small patch of minute teeth on the lower jaw;
orbit elongate; barbels slender, with barblets, with a narrow connecting membrane;
ventrals behind the middle of the length; snout decurved, prolonged, pointed; first
nostril equidistant from tip of snout and eye or nearer the latter; numerous small
pectoral pores. A foramen on each side of x in the dorsal buckler.
Habitat: Amazon, Paranahyba, Guiana.
a
KEY TO THE SPECIES OF HASSAR.
a. Fontanel not continued as a narrow groove to the dorsal.
b. Dorsal plain; eye mostly in posterior part of head; adipose fin continued forward as a ridge, longer
than anal....
59. affinis (Steindachner).
bb. Dorsal with a black spot.
c. The black spot on the first three rays, not extending to their tips; eye extremely elongate;
depth at base of pectoral equal to snout or snout and 0.4 of the eye; depth below dorsal spine
5.33-6 in the length to the last scute; head in the scapular region covered with skin, not very
rough; distance between snout and dorsal about 2.5 in the length to the end of the lateral
plates...
...60. orestis (Steindachner).
cc. The black spot on the first two rays, extending to their tip; 1 eye moderately elongate; depth
at base of pectoral at least equal to snout and half the eye; depth below the pectoral spine
about 4.66 in the length to the last scute; head in the scapular region more rugose; distance
between snout and dorsal spine 2.5-2.6 in the length to the end of the lateral scutes.
61. wilderi Kindle.
aa. Fontanel continued as a narrow groove to the tip of the occipital process. A black spot on the dorsal;
snout conical; dorsal spine with hooks on the basal part of the anterior margin; sides shaded toward
the back; lateral plates 33.....
62. notospilus (Eigenmann).
1 The dark area in Plate 29, Fig. 4 should be continued to the tip of the rays.
1

356
A REVIEW OF THE DORADIDÆ.
59. Hassar affinis (Steindachner).
Plate 27, Fig. 4.
Oxydoras affinis Steindachner, Flussf. Südam., II, 1881, p. 7, Pl. I, Fig. 1 (Rio Puty, tributary of Paranahyba
north of Therezina).
Hemidoras affinis Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 158; Occasional
Papers Cal. Acad. Sci., I, 1890, p. 258 (Rio Puty); Steindachner, Flussf. Südam., V, 1915, p. 59
(Ita picurú at Caxias; Paranahyba at Engenho da Agua).
60. Hassar orestis (Steindachner).
Oxydoras orestis Steindachner, Sb. Akad. Wiss. Wien, LXXI, 1875, p. 138, Pl. I (Xingu).
Hemidoras orestes Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 158 (Huytahy);
Occasional Papers, I, 1890, p. 258; Kindle, Ann. N. Y. Acad. Sci., VII, 1894, p. 251 (Itaituba, Brazil);
Fisher, Ann. Carnegie Mus., XI, 1917, p. 422 (Santarem).
5123, I. U. M. three. Itaituba, Brazil. Hartt.
16172, I. U. M. nine, 143-255 mm. R. Tapajos, Santarem. C. Ternetz.
16188, I. U. M. four, 133-137 mm. Amazon, Santarem. C. Ternetz.
61. Hassar wilderi (Kindle).
Plate 22, Fig. 2.
Hassar wilderi Kindle, Ann. N. Y. Acad. Sci., VII, 1894, p. 251 (Troceras on Rio Tocantins).
Known from the types only, in the collections of Indiana University and of
Cornell University.
5120 I. U. M., types, 162 and 207 mm. Troceras, Rio Tocantins.
62. Hassar notospilus (Eigenmann).
Hemidoras notospilus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, p. 394 (name only);
Mem. Carnegie Mus., V, 1912, p. 196, Pl. XIX, Fig. 2 (Crab Falls).
Known from the type, a specimen 70 mm. long, in the Carnegie Museum.
Genus XXV. LEPTODORAS Boulenger.
Leptodoras Boulenger, Ann. and Mag. Nat. Hist. (7), II, 1898, p. 478.
Type, Oxydoras acipenserinus Günther.
Air-bladder very short, its anterior end fitting into a cup-shaped downward
process of the united vertebræ, two diverticula at posterior end, a pair of diverticula
at the outer anterior corners.
Snout, preopercle and interopercle covered with skin. Slender, depth 5–9;
humeral process not half as long as the pectoral spine, about as deep as long; mouth
large, no teeth; barbels short, width of the membrane connecting the bases of the

A REVIEW OF THE DORADIDÆ.
357
mental barbels more than half their length; maxillary barbels divided beyond the
bone into an outer lateral fimbriated part and an inner part coterminous with the
mental barbels; outer mental barbel divided distally into two; a small foramen in
the dorsal buckler (or none?), a narrow groove extending back from the fontanel
tending to disappear; lateral plates 3–44, the first scute extending down to the lower
edge of the humeral process; in all but hasemani ventrals in front of the middle of
the length; adipose sharply defined behind, continued as a low crest to near the tip
of the depressed dorsal spine; snout decurved, the bones smooth; first nostril nearer
the second than to the snout; one pectoral pore.
Habitat: Amazon, Guiana.
KEY TO THE SPECIES OF LEPTODORAS.
a. Dorsal plain.
b. Dorsal spine with its membranous extension but little, if any, longer than the first ray; lateral plates
covering half or more than half of the sides.
c. Eye about 3.5–6 in the head; interorbital about half the length of the eye; distance between tip
of snout and dorsal 3 or less than 3 in the length to the end of the lateral line; distance between
the dorsals about equal to the length of the head; 38 or 39 lateral scutes; pectoral reaching
middle of ventrals; depth 6-7; a pair of parallel, dusky bands on the caudal, the middle rays
light....
63. linnelli Eigenmann.
cc. Eye 4.8–5 in the head, greater than interorbital; distance between tip of snout and dorsal more
than 3 in the length to the end of the lateral line; distance between the dorsals much longer
than the head; 42 lateral scutes; pectoral reaching base of ventral; depth 7.5.
64. acipenserinus (Günther).
bb. Dorsal spine much produced beyond the soft rays, twice as long as the head; lateral plates covering
less than half of the sides; eye 3 in snout, 1 in interorbital, 6.5 in head; maxillary barbel not reaching
gill-opening; 44 lateral scutes; pectoral reaching base of ventral; depth 9.
65. juruensis Boulenger.
aa. Dorsal with a small round spot. Dorsal spine not longer than the following ray; lateral plates covering
0.4-0.5 of the body; eye a little more than 3.5 in the head; distance between snout and dorsal 2.75 in
the length; distance between the dorsals equals length of head; 36-41 lateral scutes; pectoral not
reaching middle of ventrals; depth 5-5.5; plain..
..66. hasemani (Steindachner).
63. Leptodoras linnelli Eigenmann.
Plate 2, Fig. 2; Plate 5, Figs. 3 and 4; Plate 20, Fig. 4; Plate 24, Figs. 3 to 5.
Leptodoras linnelli Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, p. 395 (name only);
Mem, Carnegie Mus., V, 1912, p. 191, Pl. XVII, Fig. 1 and Pl. XVIII, Fig. 1 (British Guiana at
Tumatumari on the Potaro; Rockstone and Crab Falls on the Essequibo River).
Leptodoras acipenserinus non Günther, Fisher, Ann. Carnegie Mus., XI, 1917, p. 422 (Maciél, Rio Guaporé).
Hemidoras (Leptodoras) linnelli Steindachner, Flussf. Südam., V, 1915, p. 65 (Rio Branco at Boa Vista and
Serra Grande).

358
A REVIEW OF THE DORADIDÆ. .
Specimens Examined.
7188, C. M. 3. Maciel, Rio Guaporé. Haseman.
12022, I. U. M. Tumatumari. Eigenmann.
12023, I. U. M. Crab Falls. Eigenmann.
12024, I. U. M. Rockstone. Eigenmann.
64. Leptodoras acipenserinus (Günther).
Oxydoras acipenserinus Günther, Proc. Zool. Soc. London, 1868, p. 230, Pl. XX (Xeberos); Steindachner,
Flussf. Südam., II, 1881, p. 8 (Xeberos).
Hemidoras acipenserinus Eigenmann and Eigenmann, Proc. Cal. Acad. Sci., 2d Ser., I, 1888, p. 158; Oc-
casional Papers Cal. Acad. Sci., I, 1890, p. 255.
Leptodoras acipenserinus Boulenger, Ann. and Mag. Nat. Hist. (7), II, 1898, p. 478. (New genus.)
15878, one, 110 mm. Rio Paranapura at Yurimaguas. Allen. Nov. 1920.
Head 3.75; depth 8.5; width at origin of ventrals greater than depth at same
place; depth of caudal peduncle 2 in its width with the spines; D. I, 6; A. 14; scutes
4 + 42.
Width of head equals the length of the snout, greater than its depth; eye 2.5 in
snout, 4.8 in the head; interorbital 1.4 in the eye; lower profile straight; dorsal profile
arched, descending from the nostrils to the sharp snout; fontanel continued as a
narrow groove to the dorsal; top of head behind the eye granular; sides of head and
snout with pearl-organ like papillæ; mouth inferior, narrow; width of lower jaw about
1.5 in the eye; snout projecting for nearly half the length of the eye; no teeth; bases of
barbels connected by a broad membrane; maxillary barbel reaching below posterior
part of eye; gill-openings wide, the isthmus equals length of eye; dorsal spine equals
snout and half the eye, with antrorse spines on the basal half of its anterior edge,
posterior margins roughened; adipose fin much shorter than the anal; caudal deeply
forked, the lobes sharp pointed, a little greater than snout and eye; pectoral spines
equal to snout and two thirds the eye; reaching past origin of ventrals, serrate on both
margins, those on the posterior edge largest at the tip; scute less than half the depth,
with a central spine and a serrated posterior edge; humeral process half as broad as long,
reaching to middle of pectoral spines; coracoid process short, covered. Back dusky;
sides and lower parts lighter. No distinct color markings.
Both this species and linnelli have a foramen where dorsal plate and occipital
process meet.
65. Leptodoras juruensis Boulenger.
Leptodoras juruensis Boulenger, Ann. and Mag. Nat. Hist. (7), II, 1898, p. 478 (Jurua).
Known from the type only, a specimen 235 mm. long, in the British Museum.
a

A REVIEW OF THE DORADIDÆ.
359
66. Leptodoras hasemani (Steindachner).
Hemidoras hasemani Steindachner, Flussf. Südam., V, 1915, p. 61, X, Figs. 4-7 (Rio Negro at its mouth;
Rio Branco at Boa Vista and Serra Grande).
Known from the types, the largest 132 mm. long, in the Vienna Museum.
Genus XXVI. NEMADORAS Eigenmann, gen. nov.
Type, Oxydoras elongatus Boulenger.
As far as known with the characters of Opsodoras but the maxillary barbels
simple. Fontanel not continued as a groove.
KEY TO THE SPECIES.
a. Depth 5 in the length; posterior nostril twice as distant from the anterior as from the eye; eye 4.5 in the
head, 1.4 in interorbital; humeral process tapering to a point; pectoral spine as long as dorsal, nearly
as long as head; D. I, 6; A. 12; 33 lateral scutes; olive above, white below; lateral shields and fins
orange...
67. elongatus (Boulenger).
aa. Depth 3.66 in the length; posterior nostril slightly nearer the eye than the anterior nostril; eye 2 in the
snout, 4 in the head, 1.5 in interorbital; humeral process obliquely truncate posteriorly; pectoral
spine longer than dorsal, a little longer than head; D. I, 5; A. 11; 30 lateral scutes; pale olive above,
white below; fins white...
..68. bachi (Boulenger).
67. Nemadoras elongatus (Boulenger).
Plate XXI, Fig. 6.
Oxydoras elongatus Boulenger, Trans. Zool. Soc. London, XIV, 1898, p. 424, Pl. XL, Fig. 4 (Rio Jurua).
This species is known from the type, 105 mm. long, in the British Museum.
68. Nemadoras bachi (Boulenger).
Plate XXI, Fig. 5.
Oxydoras bachi Boulenger, 1.c., p. 423, Pl. XL, Fig. 3 (Rio Jurua).
This species is known from the type, 90 mm. long, in the British Museum.
24

360
A REVIEW OF THE DORADIDÆ.
EXPLANATION OF PLATES.
=
=
=
=
=
=
=
=
=
=
=
General Notations on the Various Plates and Figures.- Notations peculiar to some one plate are given
in the legend of the particular plate. For special notations for the auditory apparatus see legend of plate.
1 = Premaxillary; 2 = ethmoid; 3 = lateral ethmoid; 4 =
4 = preorbital (laminate); 5 = frontal;
6 sphenotic; 7 = pterotic; 8 = supra-occipital; 8a
supra-occipital; 8a = basi-occipital; 86 = ex-occipital; 9 epiotic;
9a = process of the epiotic; 10 = supraclavicle; 11 = parapophysis of coalesced vertebræ; 12 = maxillary;
13 = palatine; 14 = mesopterygoid; 14a = metapterogoid; 15 = quadrate; 16 = preopercle; 17 =
interopercle; 18 = opercle; 19 = hyomandibular; 20 = mandible; 21 = parasphenoid; 22 = prootic;
23 =
orbitosphenoid; 23a = alisphenoid; A. B. C. = suborbitals; D. = nasal. .
X, Y, Z = Elements of the dorsal plate.
A. IV = Anterior process of the fourth vertebra.
a = Anterior mesial articular process at base of dorsal spine.
b = Anterior articular surface of the first interneural.
c = Articular surface of the second interneural.
D. S. = Dorsal spine.
d = Opening through the base of the dorsal spine, through which the ring formed by the union of the pro-
.
longations of the first and second interneural passes.
E = Modified first dorsal spine.
e = Opening admitting blood vessels, etc., into the interior of the dorsal spine.
f = Flanges or lateral processes of the interneurals.
K = Articular surface at the tip of the lateral flange of the second interneural.
1 = Lateral articular surface at the base of the dorsal spine.
0 Modified first dorsal spine, see also E.
P. IV = Posterior process of the fourth vertebra.
Pr. IV = Process of the fourth vertebra.
Tripus.
=
=
=
=
tr
=
PLATE I.
Air-bladders of:
1. Pterodoras granulosus (Valenciennes), the ventral wall cut away exposing the inner surface of the
dorsal wall.
2. The inner surface of the ventral wall, cut away from 1.
3. Dorsal view of the bladder of Pterodoras granulosus.
4. Megalodoras irwini Eigenmann. Dorsal view of the bladder of the adult.
5. Platydoras costatus (Linnæus), front view of air-bladder showing indentations into which the process
of the fourth vertebra fits.
6. Opsodoras humeralis (Kner).
7. Trachydoras paraguayensis (Eigenmann and Ward).
8. Doras carinatus (Linnæus). Note the minute diverticulum at the middle of the lower end of the
figure, the beginning of the second air-bladder.
9. Doras carinatus (Linnæus). The interior of the anterior end of the air-bladder, seen from immedi-
ately behind the cross-partition.

A REVIEW OF THE DORADIDÆ.
361
10. Doras carinatus (Linnæus). Longitudinal median section showing particularly the ridges and
tentacles in the gullet and the air-bladder. The air-bladder shows the median partition "m,” in the posterior
part, the partial cross-partition “c," separating the posterior from the anterior part, the flexion over the
fourth vertebra "f,” and “i,” the intruded end piece of the transverse process of the fourth vertebra.
11. Astrodoras asterifrons (Heckel).
12. Centromochlus heckelii Filippi, and
13. Trachycorystes insignis of the Auchenipteridæ.
14. Platydoras costatus (Linnæus).
15. Oxydoras kneri Bleeker.
16. Pseudodoras niger (Valenciennes).
17. Doras micropæus (Eigenmann).
18. Rhinodoras d'orbignyi (Kröyer).
PLATE II.
Fig. 1. Doras micropæus (Eigenmann). I. U. M., 12029, 245 mm., Lama Stop-Off.
Fig. 2. Leptodoras linnelli Eigenmann. I. U. M., 12022, about 180 mm., Tumatumari.
Fig. 3. Acanthodoras spinosissimus (Eigenmann and Eigenmann). I. U. M., 16005, 63 mm., Maciel.
Fig. 4. Opsodoras humeralis (Kner). I. U. M., 15881, about 120 mm., Iquitos.
Fig. 5. Trachydoras atripes Eigenmann. I. U. M., 16006, about 100 mm., S. Joaquin.
Fig. 6. Doras carinatus (Linnæus). I. U. M., 12026, about 185 mm., Rockstone.
Fig. 7. Lithodoras dorsalis (Valenciennes). I. U. M., 4248, about 165 mm., Pará.
Fig. 8. Centromochlus heckelii Filippi. Auchenipteridæ.
Fig. 9. Trachycorystes insignis (Steindachner). Auchenipteridæ.
PLATE III.
Fig. 1. Platydoras costatus (Linnæus). I. U. M., 77 mm., Rio Morona.
Fig. 2. Platydoras costatus (Linnæus). I. U. M., 17041, 185 mm., Lake Rogoagua.
Fig. 3. Megalodoras irwini Eigenmann. I. U. M., 15427, about 300 mm., now shrunken, Iquitos.
Fig. 4. Centrochir crocodili (Humboldt). I. U. M., 13557, about 175 mm., Soplaviento.
Fig. 5. Doras punctatus Kner. I. U. M., 15883, about 95 mm., Lake Cashiboya.
Fig. 6. Pterodoras granulosus (Valenciennes). I. U. M., 15847, 165 mm. to end of middle caudal ray,
Iquitos.
Fig. 7. Franciscodoras marmoratus (Reinhardt). After Steindachner.
Fig. 8. Trachydoras paraguayensis (Eigenmann and Ward). I. U. M., 16009, 81 mm. to end of
middle caudal rays, S. Joaquin.
Fig. 9. Amblydoras hancocki (Cuvier and Valenciennes). I. U. M., 12034, about 95 mm., Maduni
Creek.
PLATE IV.
Fig. 1. Hypodoras forficulatus Eigenmann. I. U. M., 15876, type, 123 mm., Iquitos.
Fig. 2. Astrodoras asterifrons (Heckel). I. U. M., 16003, 97 mm., Jutahy.
Fig. 3. Scorpiodoras heckeli (Kner). I. U. M., 16002, 161 mm., Teffé.
Fig. 4. Astrodoras asterifrons (Heckel). I. U. M., 16035, 80 mm., Santarem.
Fig. 5. Acanthodoras cataphractus (Linnæus). I. U. M., 12032, about 82 mm., Gluck Island.
Fig. 6. Anadoras weddelii (Castelnau). I. U. M., 5110, 113 mm., Marajo.
Fig. 7. Anadoras grypus (Cope). I. U. M., 15849, about 120 mm., Lake Cashiboya.

362
A REVIEW OF THE DORADIDÆ.
PLATE V.
Radiographs by Dr. J. E. P. Holland.
Figs. 1 AND 2. Platydoras costatus (Linnæus).
Figs. 3 AND 4. Leptodoras linnelli Eigenmann.
Figs. 5 AND 6. Centrochir crocodili (Humboldt).
PLATE VI.
Photographs of Megalodoras irwini Eigenmann. I. U. M., 15427, about 300 mm.
Fig. 1. Membrane bones of left side from without.
FIG. 2. Dorsal view.
Fig. 3. Suborbitals and preorbital.
Fig. 4. Ventral view of the skull and membrane bones.
PLATE VII.
Megalodoras libertatis (Ribeiro).
Drawings of the type by E. Cruzlima. Loaned by Dr. A. Ribeiro.
PLATE VIII.
Photographs of Pterodoras granulosus (Valenciennes).
Fig. 1. Side view. I. U. M., 15848, 180 mm., R. Puinahua.
Fig. 2. Dorsal view of the same.
Fig. 3. Side view of another specimen, skeletonized.
Fig. 4. Ventral view of skull and membrane bones.
PLATE IX.
Fig. 1. Side view of a young specimen of Platydoras costatus (Linnæus). I. U. M., 15874, 82 mm.,
Lake Yarinococha.
Fig. 2. Dorsal view of an older specimen.
Fig. 3. Side view of skeleton. I. U. M., 17041, Lake Rogoagua.
Fig. 4. Ventral view of Centrochir crocodili (Humboldt). 13557, about 175 mm., Soplaviento. See
Plate III, Fig. 4.
Fig. 5. Centrochir crocodili (Humboldt). From Steindachner.
Fig. 6. Lithodoras dorsalis (Valenciennes). I. U. M., 4248 mm., about 165 mm., Pará. See Plate
II, Fig. 7.
PLATE X.
Figs. 1 AND 2. Acanthodoras cataphractus (Linnæus). I. U. M., 12032, 86 mm., Gluck Island.
Figs. 3 AND 4. The same from a specimen 80 mm.
Fig. 5. Acanthodoras calderonensis (Vaillant). After Steindachner.
PLATE XI.
Figs. 1 AND 2. Acanthodoras spinosissimus Eigenmann and Eigenmann. C. M., 7167, Maciél.
Figs. 3 AND 4. The same. I. U. M., 16005, 93 mm., Maciél.

A REVIEW OF THE DORADIDÆ. .
363
PLATE XII.
E. N.
Fig. 1. Megalodoras uranoscopus Eigenmann and Eigenmann. M. C. Z. type, 530 mm.
Fischer, del.
Fig. 2. Dorsal view of the same specimen.
PLATE XIII.
Amblydoras hancockii (Cuvier and Valenciennes).
Figs. 1 AND 2. I. U. M., 12034, 118 mm., Maduni Creek.
Fig. 3. I. U. M., 12033, 112 mm., Lama Stop-Off.
Fig. 4. I. U. M., 12034, 95 mm., Maduni Creek.
PLATE XIV.
Anadoras insculptus (Ribeiro).
Drawings by E. Cruzlima, based on the type in the Museu Nacional, Rio de Janeiro.
has kindly loaned these drawings.
PLATE XV.
Dr. A. Ribeiro
Figs. 1-3. Anadoras grypus (Cope). 1 and 2, I. U. M., 15849, 139 mm., Lake Cashiboya. 3,
118 mm., Lake Cashiboya.
Fig. 4. Anadoras weddelii (Castelnau). I. U. M., 5110, 113 mm., Marajo.
PLATE XVI.
Fig. 1. Ventral view, 2. dorsal view of Physopyxis lyra Cope. Type in Mus. Phila. Acad. Sci.
Fig. 3. Amblydoras monitor (Cope). Type in Mus. Phila. Acad. Sci.
Fig. 4. Agamyxis pectinifrons (Cope). Type in Mus. Phila. Acad. Sci.
PLATE XVII.
Figs. 1-4. Pseudodoras niger (Valenciennes). Figs. 1 and 2, side and dorsal views of a specimen
I. U. M. 16004, 273 mm. to end of the scutes, Rio Pacaya. Allen. Figs. 3 and 4, I. U. M., 15651, about
237 mm., Iquitos.
PLATE XVIII. .
Figs. 1 AND 2. Trachydoras nattereri (Steindachner). I. U. M., 15967, 131 mm., Iquitos.
Figs. 3–5. Trachydoras paraguayensis (Eigenmann and Ward). Fig. 3, C. M., part of 7201, San
Joaquin. Figs. 4 and 5, I. U. M., 16009, 81 mm. to end of middle caudal rays, San Joaquin.
Figs. 6–8. Trachydoras atripes Eigenmann. Figs. 6 and 7, I. U. M., 16006, about 100 mm., San
Joaquin Fig. 8, C. M., part of 1201, San Joaquin.
Figs. 9–10. Opsodoras humeralis (Kner). I. U. M., 15881, about 120 mm., Iquitos.
PLATE XIX.
Fig. 1. Opsodoras humeralis (Kner). I. U. M., 15881, 138 mm., Iquitos. W. S. Atkinson, del.
Fig. 2. Opsodoras hemipeltis Eigenmann. I. U. M., 50879, type, 143 mm., Contamana. W. S.
Atkinson, del.
Fig. 3. Opsodoras parallelus Eigenmann. I. U. M., 15964, type, 151 mm., Iquitos. W. S. Atkinson,
del.

364
A REVIEW OF THE DORADIDÆ.
PLATE XX.
Figs. 1-2. Doras carinatus (Linnæus). I. U. M., 12026, about 185 mm., Rockstone.
Fig. 3. Doras micropæus (Eigenmann). I. U. M., 12029, 245 mm., Lama Stop-Off.
Fig. 4. Leptodoras linnelli Eigenmann. I. U. M., 12022, about 180 mm., Tumatumari.
PLATE XXI.
Figs. 1 AND 2. Doras punctatus Kner. I. U. M., 15882, 118 mm., R. Paranapura, Yurimaguas.
Figs. 3 and 4. Doras eigenmanni (Boulenger). After Boulenger.
Fig. 5. Nemadoras bachi (Boulenger). After Boulenger.
Fig. 6. Nemadoras elongatus (Boulenger). After Boulenger.
PLATE XXII. .
Fig. 1. Franciscodoras marmoratus (Reinhardt). After Lütken.
Fig. 2. Hassar wilderi Kindle. I. U. M., 5120, type, about 165 mm., Troceras. W. S. Atkinson, del.
Fig. 3. Opsodoras orthacanthus Eigenmann. 1. U. M., 15884, type, 133 mm.; Iquitos. W. S.
Atkinson, del.
PLATE XXIII.
Fig. 1. Pseudodoras niger (Valenciennes). T. R. S., No. 743, 840 mm., Koriabo, Guiana. Photo
by John Tee-Van of a giant specimen from Kartabo.
Fig. 2. Opsodoras orthacanthus Eigenmann. I. U. M., 15884, type, 133 mm., Iquitos. See Plate 22,
Fig. 3.
Fig. 3. Opsodoras parallelus Eigenmann. I. U. M., 15964, type, 151 mm., Iquitos. See Plate 19,
Fig. 3.
Fig. 4. Doras carinatus (Linnæus). I. U. M., 12026, 233 mm. to end of middle caudal rays,
Rockstone.
PLATE XXIV.
Figs. 1 AND 2. Doras micropæus (Eigenmann). Fig. 2, I. U. M., 12029, 245 mm., Lama Stop-Off.
Figs. 3-5. Leptodoras linnelli Eigenmann. Fig. 3, I. U. M., 12022, 167 mm., Tumatumari. Fig.
4, The same specimen from below. Fig. 5, I. U. M., 12022, about 180 mm., Tumatumari. See Plate 2,
Fig. 2.
Fig. 6. Opsodoras hemipeltis Eigenmann. I. U. M., 15964, type, 151 mm., Iquitos.
PLATE XXV.
Fig. 1. Megalodoras irwini Eigenmann. T. R. S., 2567, 612 mm., Kartabo.
Fig. 2. Megalodoras irwini Eigenmann. I. U. M., 15427, type, 278 mm., Iquitos. W. S. Atkinson,
del.
Fig. 3. Hypodoras forficulatus Eigenmann. I. U. M., 15876, type, 123 mm., Iquitos. W. S.
Atkinson, del.
PLATE XXVI. .
Fig. 1. Trachydoras paraguayensis (Eigenmann and Ward). I. U. M., 10127, type, 87 mm.,
Corumba. W. S. Atkinson, del.

A REVIEW OF THE DORADIDÆ.
365
Figs. 2 AND 3. Trachydoras nattereri (Steindachner). After Steindachner.
Fig. 4. Trachydoras atripes Eigenmann. I. U. M., 15877, type, 60 mm. to end of lateral scutes,
Iquitos. W. S. Atkinson, del.
Fig. 5. Rhinodoras d'orbignyi (Kröyer). I. U. M., 9837, type of Doras nebulosus Eigenmann and
Ward, 160 mm., Asuncion. W. S. Atkinson, del.
PLATE XXVII.
Figs. 1 AND 2. Opsodoras morei (Steindachner). After Steindachner.
Fig. 3. Hemidoras morrisi Eigenmann. I. U. M., 15962, type, 147 mm., Iquitos. W. S. Atkinson,
.
del.
Fig. 4. Hassar affinis (Steindachner). After Steindachner.
Fig. 5. Doras micropæus (Eigenmann). I. U. M., 12029, about 355 mm., Lama Stop-Off. W. S.
Atkinson, del.
Figs. 6-7. Opsodoras stübeli (Steindachner). After Steindachner.
Fig. 8. Doras carinatus (Linnæus). I. U. M., 12025, about 235 mm., Tumatumari. W. S. Atkin-
.
son, del.


TRANS. AM PHILOS. SOC., N. S. XXII.
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TRANS. AM. PHILOS. SOC., N. S. XXII.
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TRANS. AM. PHILOS. SOC., N. S. XXII.
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TRANS. AM. PHILOS. SOC., N. S. XXII.
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TRANS. AM. PHILOS. SOC., N. S. XXII.
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