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1872
FISHES

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NATURAL SCIENCES OF PHILADELPHIA. 249

OcToBER 24.
The President, Dr. RuscHENBERGER, in the chair.

Highteen members present.

OcroBer 31.
The President, Dr. RUsCHENBERGER, in the chair.

Twelve members present.

On report of the committee, the following paper was ordered
to be printed :—

1872.]

ea E FISHES OF THE AMBYIACU RIVER,/
Be ewes: BY EDWARD D: COPE.

The collection on which the present examination is based was
made by our correspondent at Pebas, John Hauxwell. It em-
braces fishes of the small streams tributary to the Ambyiacu, as
well as those of the river itself. The Ambyiacu is an inconsid-
erable river, which empties into the Amazon near to Pebas, in
Eastern Equador, some distance east of the Napo.

The results of the examination will be mentioned at the close
of the list. As was to have been supposed, it consists almost
exclusively of representatives of the three great families which
abound in the neotropical region; the Chromididex, representing
Physoclystous fishes, and the Characinide and Siluridex, repre-
senting the Physostomi. The number of new species, forty-five
ina total of seventy-four, constitutes a considerable addition to
ichthyology, especially as the number of new generic forms is also
rather large.

I add a list of the species obtained by my friend Robert Per-
kins, of Wilmington, Delaware, on a trip between the mouth of
the Rio Negro and the Peruvian Amazon or Ucayale River. There
are several interesting novelties in this collection, but their spe-
cial localities are, unfortunately, not preserved. The specimens
generally were large, and in fine condition.

CHROMIDIDZ:.

PTEROPHYLLUM SCALARE, C. V.
Heckel, Ann. Wien. Mms., 1840, 334. Gimnther, Catal. B. M. v. 316.

Abundant in the Ambyiacu.

GEOPHAGUS AMOENUS, Cope, sp. nov.

Allied to G. teeniatus (Mesops, Giinth.). Scales in three series
on the cheek; on the body, 2-25-8. Fin radii D. xv. 7, A. iii. 6.
Twelfth dorsal spine less than half the length of the head; spines
subequal, slightly shortening anteriorly. Prolonged soft rays of
dorsal and anal extending beyond the caudal. Pectoral to, ven-
tral beyond, base of anal. Length of head less than depth of

[January 16,

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10% NATURAL SCIENCES OF PHILADELPHIA. Dil
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body, nearly four inches in length (with caudal); depth, 3.5 times
in the same. Orbit, twice preorbital bone, equal muzzle, one-
fourth wider than interorbital space, one-third head.

Total length .063 m.; to basis anal .0335; do. ventral .019;
do. dorsal (axial) .015 m. Color brown; a black band from
orbit to basis caudal. A black spot at base, and one at tip of
caudal. Basis of dorsal and anal brown, rest yellow. A black
band from orbit to angle of interoperculum. Cheeks and opercu-
lum with blue spots separated by yellow lines. River Ambyiacu.

GEOPHAGUS BADIIPINNIS, Cope, sp. nov.

Form short oval; body deep; front steeply descending, concave
between the orbits; the muzzle projecting. Depth one-half length
without caudal fin; head 2.4 times in the same. Orbit 3.5 times
in length of head; 1.3 times into interorbital space, which equals
length of muzzle with under jaw. Preorbital bone .75 the dia-
meter of the orbit. End of maxillary bone falling opposite the
pupil. Fin rays D. xiii-12, A. iii-ll. Scales 3-27-8-103; six
series on the cheek; operculum scaled. Twelfth dorsal ray equal
length of muzzle plus half of orbit; the rays gradually diminish-
ing in length to the second. Caudal fin broadly scaly at base ;
no scales at base of second dorsal. Pectoral fin long, extending
to opposite last soft dorsal ray; ventrals to third soft anal.

Color golden, blue bands on the prefrontal bone, and longitu-
dinal shades on the scales. Dorsal fin dusky spotted, anal with
numerous bay-yellow spots in vertical rows. Total length .15 m.;
to origin dorsal (vertical line) .043; do. to ventral .051; do. anal
084.

This species, having the coloration of G. jurupart, has the orbit
nearly as median as in G. taeniatus. I do not see the necessity
of subdividing Heckel’s genus Geophagus into three (Geophagus,
Satanoperca,and Mesops),as has been proposed by Gunther (Catal.
Brit. Mus.).

GEOPHAGUS JURUPARI, Heckel.

Satanoperca jurupart, Ginth. Cat. B. M. v. 313.

D. xv. 10, A. iii. 7. Scales 3-31-9; suborbitals 6 (7) rows. Pre-
orbital bone 1.66 times orbit.

952 PROCEEDINGS OF THE ACADEMY OF

CRENICICHLA ANTHURUS, Cope, sp. nov.

A slender species, with brightly colored fins. Depth six times
in total length, or 5.3 times in length without caudal fin. Length
of head 3.66 in total length, five and two-third times more than
the diameter of the orbit. Orbit 1.7 times in muzzle, 1.6 times in
interorbital width, which is flat. Scales 44-36-7-13, but, as those
of the lateral line are placed at intervals, the true number of
transverse series of scales is 62.3; scales of cheek in nine series.
Fin radii, D. xix-13; A.iii-9. Caudal cuneate rounded; pectoral
and ventral coequal, not extending half-way to anal. Twelfth
dorsal spine equalling from end of chin to orbit. Some rays of
soft dorsal and anal prolonged, the former to near end of caudal,
the latter to base.

Color leaden-brown above, fading into yellowish below. Dorsal
and anal fins deep rose, with a few round small spots of pale
rose on the soft portions, which become white in spirits. Caudal
fin deep crimson, fading to purple at base, with a longitudinal
dark shade in the centre, and series of small oval pink spots, one
between each pair of rays. <A black spot edged with white at the
base above the lateral line, and a larger black spot, white-edged,
crossing the lateral line opposite the third, fourth, and fifth dorsal
spines.

Total length .215 m.; to basis dorsal (axial) .055 m.; to basis
of anal .121.

This perch appears to be similar to the C. lacustris of Castel-
nau in proportions, but the coloration is very different. I have
three specimens from the Ambyiacu. It is less slender than the
C. luctus, Cope,' and has a considerably wider skull.

CRENICICHLA PROTEUS, Cope, sp. nov.

This species is represented by numerous specimens, which vary
in many respects from an average standard, constituting several
varieties, one of which may turn out to bea species. The typi-
cal or most numerous form may be thus described :—

Radii D. xix-13; A. ili. 8 or 9. Depth of body from four to
four and a half times in length without caudal fin. Head 3
times in same, orbit 5 times in head, 1.25 times in muzzle, and

1 Proceed. Amer. Philos. Soc., 1870, 570.
[January 16,

NATURAL SCIENCES OF PHILADELPHIA. is

1.33 times to 1.6 times in interorbital breadth. Scales 4—56-3'—12
13, seven rows on cheek. Color olivaceous, blackish above; fins
dusky, without markings, except a black ocellus at upper base of
caudal fin, with pale margin. A dusky band from end of muzzle
to middle of side, and dusky spot below eye. Eye red. Total
length .17 m.

Var. a.—Shorter and stouter, colors paler. Eye 1.5 times in
interorbital width. Depth of body 34 to 4 times in length less
caudal. Scales 4—45-8—13. Pattern of color similar to the last.
Several specimens.

Var. 6B.—More slender; depth 4.66 times in length without
caudal fin. Radii xviii-l4; A. iii-9. Scales 4-55-13. Diameter
of orbit equal interorbital space. Coloration as in the types, ex-
cept a large black spot marking the posterior fourth of the spinous
dorsal fin. This variety has one less dorsal spine than usual in
the type, but the latter occasionally exhibits but 18.

Var. y (argynnis).—Short and stout as in var. a, but the
orbit is as wide as the narrowed interorbital space; scales 4—43-
13. Radii D. xix. 13; A.iii. 9. The coloration is like that of the
type, olive, darker above, with caudal ocellus and dusky band
from muzzle to opercular margin. The dorsal fin has, however, a
broad orange-red band extending along its distal posterior half,
the anterior part wider and with three large black spots in the
centre; in a second specimen it contains four black spots.

The preceding varieties are so connected together as to be in-
separable in our system. ‘The var. 6 accords to some extent with
Castelnau’s description of his C. lacustris, but our most slender
forms are less elongate than this species, where the depth is one-
sixth the length. There are neither black dots nor vittse in the
C. proteus. From C. saxatilis, to which it is next allied, it dif-
fers in the constantly smaller number of longitudinal scales, which
are given by Gunther as 14.

UARUS INSIGNIS, Heckel.
Mesonauta insignis, Giinther, 1. c. iv. 300.
UARUS CENTRARCHOIDES, Cope, sp. nov.

Form a compressed broad oval. Scales ctenoid T—29-20—14,
five series on the cheek; operculum scaled. Radii D. xv—14; anal

1 Not counted on lateral line.

1872.]

954 PROCEEDINGS OF THE ACADEMY OF

viii-12. Caudal fin subtruncate. The middle dorsal spines appear
to be longer than the posterior, but the latter with the two ante-
rior pointed rays have been bitten nearly off, causing a deep and
regular emargination of the two firs, so that the normal form is
notcertain. Pectoraland ventral fins extending to near the eighth
anal spine. ‘Teeth in several series in both jaws, those of the ex-
ternal cylindric considerably larger. End of maxillary extending
but little behind the line of the posterior nareal opening. Profile
steep, concave and flat between the orbits, where its width a little
exceeds the diameter of the orbit. Latter one-third of head
equal length of muzzle. Depth of body 1.5 times the length
without caudal fin.

Color dusky, with seven vertical blackish bars extending below
the basis of the dorsal fin, which break into spots on the belly; a
cross-bar through eye, and one across base of tail. Soft dorsal
with whitish cross-bars, other fins blackish.

Total length .074 m.; to line of D. I. .02 m.; to line of A. I.
-03; to basis of caudal .055.

This species is intermediate in characters in some respects be-
tween the species referred by Gunther to Uarus, Heckel (‘ Varu”’),
and those referred to Mesonauta, Giinther. I fail to perceive any
characters on which to establish the latter, and accordingly regard
its species as referable to the present genus.

HEROS BIMACULATUS, Linn.

Acara bimaculata, Giinther, 1. c. 276; A. gronovit, punctata et margarita,
Heckel fide Giinther.

This appears to be the only species of the Acaras of Giinther
which possesses four anal spines, the remaining species possessing
three. Heros, Heckel, is distinguished, according to the same, by
the possession of five spines in the anal fin. Out of eighteen speci-
mens of the present fish from the Ambyiacu, four possess five spiness
the remainder four; I am therefore disposed to define Acara as
having three, and Heros as having four or five anal spines, though
it is possible that it will be found necessary to unite the two
genera,

{January 16,

NATURAL SCIENCES OF PHILADELPHIA.

i)
Or
on

ACARA TETRAMERUS, Heckel.
Giinther, Catal. iv. 277. '
ACARA SYSPILUS, Cope, sp. nov.

Scales in three series on the cheek, on the body 2-26-7. Radii
D. xiv-xv. 9; A. iii. 8; caudal rounded. Form elongate oval;
depth of body 2.6 times in length without caudal fin, and equal
depth of head. Preorbital bone half orbit (in specimen two inches
long); orbit 2.5 times, head nearly twice interorbital space
(doubtless much smaller in larger specimens). Profile convex;
muzzle oblique; upper lip longer than mandible.

Light brown, yellow below. A straight wide black band from
the upper posterior margin of the orbit to below the end of the
spinous dorsal, composed of three confluent spots; a black bar
from eye to angle of preoperculum, and another across the base
of the caudal fin. Seven vertical brown cross shades behind the
head, on sides.

ACARA FLAVILABRIS, Cope.

Proc. Amer. Phil. Soc., 1870.

Scales in two series on cheek; on body 2-24-8. Radii D. xvi.
9-10; A.iii. 7. Depth 2.25 times, head 2.8 times in length less
caudal fin. Eye three times length. of preorbital bone, and 2.6
times in head in specimen 2.5 inches long, jaws equal. Seventh
dorsal spine as long as diameter of orbit or interorbital width.
Profile gently convex, inferior outline rising to meet it.

Olive, with jointed unpaired fins yellow. A large black spot
before middle of side on lateral line, a vertical shade at base of
caudal.

As compared with A. dimerus, its closest ally, this fish differs
in the fewer anal radii, the lack of cross-bars, etc. It was origi-
nally described by me as having three rows of cheek scales; but
those of the interoperculum were included.

ACARA FRENIFERUS, Cope, sp. nov.

Scales of cheek in two series; of body 2—29-8—9. Radii D.
xvi. 10-11; A. ili. 8. Form elongate oval, the depth entering the
length (less caudal) 2.33 times. Front convex, descending, length
of head one-third length. Orbit equal muzzle 3.33 times in head,
1.5 times in the flat front. Dorsal spines short, twelfth equalling

1872.]

256 PROCEEDINGS OF THE ACADEMY OF

diameter of orbit. Pectoral not reaching anal; soft anal and
dorsal not quite reaching end of caudal; latter rounded.

Color rich brown, with a black spot under the middle of the
dorsal fin, which is connected with the orbit by a broad black
band. The body is further crossed by five darker shades. Fins
dusky. Below brown, under lip yellow.

Total length .117 m. to line of D.i. .027; do. of anal .058.

Several specimens from the Ambyiacu. This species is, with A.
dimerus, Heckel, and A. flavilabris, Cope, the only one with two
series of cheek scales. It differs from the first named in the much
fewer fin radii, ete.

ACARA COMPRESSUS, Cope.

Scales 35, transverse series, seven rows on the cheek. Radii D.
xili-l9; A. iii-15. Longest dorsal spine as long as muzzle and
half the orbit. Form oval, depth half length less caudal, body
compressed. Profile oblique, nearly straight from in front of
dorsal fin. Head 2.5 times in length less caudal; orbit 3.2 times
in head, larger than muzzle 1.2 times in interorbital space. Left
dorsal and anal prolonged. Outer series of teeth larger. Total
length .079 m.; to dorsal (axial) .024; to anal (do.) .0395; to
caudal fin .0595.

Color, injured by the alcohol, at present uniform brown, with a
black line from the angle of the mouth to that of the preoperculum,
and two black shades, one at base and the other at end of caudal
fin. Soft dorsal and anal black behind.

Two specimens from the Ambyiacu.

HYGROGONUS OCELLATUS, Agass.
Spix, Pisce. Brasil., tab. 68.

CLUPEIDA.

PELLONA ALTAMAZONICA, Cope, sp. nov.

No teeth on the vomer, a distinct series on the palatine bones;
the whole of the hyoid axis and tongue covered with dentigerous
plates. Bi-maxillary and maxillary teeth, the former considerably
longer. Scales 23-77. Fin rays D. 18, A. 38-39. Dorsal fin
behind the ventral, its origin nearer the basis of the caudal fin
than the end of the muzzle, its last ray above the first anal ray.
Length of ventral fin equal diameter of orbit. Superior caudal

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. D5 7

lobe shorter than inferior. Orbit entering head (with chin) four
times, in muzzle once, nearly double interorbital space. Pectorals
reaching beyond basis of ventrals. Cranial ridges forming a
closed V in front. Length of head equal greatest depth of body,
entering length 3.75 times (excl. caudal fin).

Total length .186 m; to basis of anal .093 (axial); do. ventral
O61.

Silver with golden and green reflections, yellow on side of head,
a black epiclavicular spot.

From the Ambyiacu. The second South American species,
which is found at a great distance from salt water.

OSTEOGLOSSIDZ.
OSTEOGLOSSUM BICIRRHOSUM, Vand.

Three specimens; in one the anal and caudal fins are united.

STERNOPYGIDZ.

This family differs materially from the Gymnotidex, with which
its species have been heretofore arranged. One character is to be
seen in the construction of the scapular arch. The coracoid bone
is well developed, and connected by the transverse column with
the clavicle, as in many other physostomous families. In the
Gymnotide this column is wanting, and the coracoid is rudi-
mental.

STERNOPYGUS MACRURWUS, Cuv.
STERNOPYGUS VIRESCENS, Valenc.

CARAPUS FASCIATUS, Pallas.

ERYTHRINIDA.

MACRODON TRAHIRA, Bl. Schn.
Giinther, Catal. v. 281.

HOLOTAXIS LETUS, Cope, sp. nov.

Form elongate, scales very large, |. 1. 26,1. tr. 5. Length head
four times depth body, also four times in length without caudal
fin. Orbit 3.3 times in length of head. Chin very prominent ;
maxillary teeth as large as the premaxillaries. Dorsal fin distant
from muzzle 1.5 times distance from caudal. Radii D. I. 9; A.
1872.]

258 PROCEEDINGS OF THE ACADEMY OF

10; V.8. Pectoral reaching ventrals, ventrals filamentous, reach-
ing anal, commencing in front of dorsal.. Dorsal with median
rays, and caudal with longest rays filamentous.

Color, scales orange at base, with broad blackish margins form-
ing rows of spots; dorsal fin with a black spot at middle and a
large black saddle below and in front of it on the back; mandi-
ble black-edged; fins orange-red. Total length .0755 m.; to
dorsal fin .0335; to ventrals .027; to anal .0416.

This is the second species of this genus, which was character-
ized by the writer, Proceedings Am. Phil. Soc., 1870, p. 563. It
differs from the type H. melanostomus, in the larger scales, there
being 5 in this, 7 in that, in a cross series.

CHARACINID.

CURIMATUS CYPRINOIDES, Linn.
Syst. Nature ; Ginther, Cat. B. M. v. 290.

CURIMATUS RUTILOIDES, Kner.
Denkschr. Wien. Acad., 1859,141. Giimth. vy. 290.

Both these species quite abundant.

PROCHILODUS INSIGNIS, Kner.
Denkschr. Wien. Acad., 1859, 147. Giinth. v. 296.

D.11, A. 10. L.1. 44, 1. tr. 22. Depth 2.5 times in length ;
head three times. Silver-leaden above; caudal with two black
cross-bands forming chevrons with the angle directed distally.

Dorsal with three, anal with two dark bands. <A single small spe-

cimen.
ANOSTOMUS FASCIATUS, Spix.

Pisc. Braz. t. 36. Giinth., Cat. B. M. v. 304.
LEMOLYTA, Cope, gen. nov.

Allied to Schizodon (Anostomus) in all respects, 7. e. with mova-
ble flat incisor teeth in the jaws, but differing in having the
branchiostegal membranes entirely free from the isthmus. They
are united to each other only, and the connecting membrane
bridges the isthmus throughout its length. In the only species
known to me the inferior teeth are truncate with entire margin,
or incisor-like ; the superior are crenate.

[January 16,

NATURAL SCIENCES OF PHILADELPHIA.

bho
on
Lie)

LEMOLYTA TAHNIATA, Kner.
Schizodon teniatus, Kner. Denkschr. Ac. Wien, 1859, 159. Gthr., v.
304,
LEPORINUS MEGALEPIS, Giinth., var.

Catal. B. M. v. 307.

Three adult specimens, two with deeper, one with shallower
body. First, scales 44-35-4; head 3.5 times, depth three times in
length. Second, scales 5-37-5; head 3.75, depth three times in
length. Third, scales 5-38-5; head 3.75, depth 3.6 times in
length. All with anal rays 10, and a minute anterior spine. Ten
dark dorsal cross-bands besides the three lateral spots; the ap-
propriate bands descending between the spots. The young are
very strongly and handsomely cross-banded.

CHARACIDIUM ETHEOSTOMA, Cope, sp. nov.

The discovery of this little fish is interesting as extending the
range of this genus over the whole of Brazil, it having been known
heretofore from the neighborhood of Lagoa Santa, from a tribu-
tary of the coast river, the Rio das Velhas. Prof. Reinhardt,
who discovered it, called the species from that locality Ch. fas-
ciatum.| The nares are separated, the anal fin short, the teeth
are simple, acute, and fixed in a single series in each jaw; none
on the maxillary. Lateral line complete.

The species here described has much the coloration of the
Poecilichthys or Etheostoma of our North American streams.

Depth into length 5.25 times; head 5.75 times in same. Bran-
chiostegal membranes fissured far forwards. Dorsal fin commencing
in front of ventrals R. 11; A. 8; V.9; P.11, reaching ventrals,
ventrals reaching anal, caudal deeply forked. Scales 1. 1. 33, 1. tr,
8; striate. Orbit equal muzzle 3.6 times in head, equal inter-
orbital width, and length of muzzle; profile nearly straight, lips
about equal; maxillary bone to orbit.

In spirits yellowish, probably hyaline in life, with a black lateral
band from end of muzzle, and nine quadrate brown dorsal spots
from nape to tail. There is more or less connection between the
spots and band, and shades across the under side opposite to
these. Fins unicolor, light. Sides of head silver, end of chin,

1 See K. Dansk. Y. Selsk. Forh., 1866, 55, Tab. II. f. 1.
1872. ]

260 PROCEEDINGS OF THE ACADEMY OF

and a vertical bar at base of caudal fin black. Total length
-048 m.; to dorsal .0175; to anal .03; to basis caudal .039. The
opercle of one of the specimens is white and smooth, cf another
punctate-rugose and yellow.

IGUANODECTES, Cope, gen. nov.

Dorsal fin originating in advance of ventrals, anal elongate.
Branchiostegal membranes united across, but not with, isthmus.
Teeth in two series in the premaxillary, none in the maxillary, and
one row in the mandible. They are fixed, but have contracted
fangs, and broad, flat, subequally denticulate crowns, and those of
the mandible stand out from the dentary bones all round. Teeth
of the outer row very few, minute. Caudal fin furcate.

This genus is allied to Tetragonopterus, but the dentition is
much weaker, approaching that of the Schizodon; the union of
the branchiostegal membranes is seen in Lemolyta m. In the only
species there are but two minute teeth of the outer premaxillary
row. ‘The other teeth are fan-shaped and smooth, and in contact,
so as to form an uninterrupted series. In Tetragonopterus the
fangs are strong, not contracted, and the crowns are ridged.

IGUANODECTES TENUIS, Cope, sp. nov.

Slender, the depth entering the length (without caudal) 5.5
times, length of head 4.33 times in the same. Radii D. 12; A. 36;
V.9, P. 13. Pectoral reaching ventral and ventral anal. Orbit
3.2 times in head, equal interorbital width, less than length of
muzzle. L. tr. al. A.i. 11-12. Caudal furcate. Distance from
base dorsal to base caudal equal from former to pupil of eye.
Color pale, a silver band along side; base of caudal blackish.
Total length .059 m.; to basis dorsal .027; to basis anal .0275.

APHYOCHARAX PUSILLUS, Gthr.
Proc. Zool. Soc. Lond., 1868, 245.
Fins bright red in life.
TETRAGONOPTERUS CHALCEUS, Artedi.
Agass. Cuv. Val., Gthr. Catal. v. 320.

TETRAGONOPTERUS BARTLETTII, Gthr.
Am. Magaz. Nat. Hist., 1866, 30.

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. 261

TETRAGONOPTERUS PHENICOPTERUS, Cope.

D. 10; A. 26-7; ventrals originating in front of dorsal, not
reaching anal; pectoral reaching ventral. Scales 54-35-4. Depth
of body 3.3 times in length without caudal; length of head 4.2
times. Orbit 2.5 times in head, equal the plane interorbital space.

Silvery, with lateral silver band and indistinct scapular and
basal caudal blackish spots. Anal and dorsal fins vermilion;
caudal with a triangular vermilion spot which surrounds the
basal black spot, and whose apex reaches the caudal emargina-
tion.

Length .053 m.; to dorsal .021; to anal .0245.

Apparently very abundant. It is allied to the 7. caroline of
Dr. Gill (Proc. Ac. Nat. Sci., Phila.), 1870, p. 92, but is a more
slender fish with smaller head.

STETHAPRION CHRYSEUM, Cope, sp. nov.

Form elevated, disciform ; scales small, 19-67-16. Radii D.
12; A. 37; V.8, very small, not reaching anal, and commencing
below dorsal. Pectoral falcate reaching nearly to line of end of
ventrals. Base of anal fin covered with scales, especially ante-
riorly ; dorsal with a long decurved spine in front of it. Caudal
peduncle contracted. Depth into length less caudal fin, 1.66
times, length of head 3.4 times. Orbit 2.4 times in head, much
larger than muzzle’s length, 1.1 times in interorbital width. Pro-
file of head very concave. Dorsal fin elevated, caudal deeply bi-
furcate. Lateral line a little decurved medially.

Color silvery, a leaden shade from postscapular region to caudal
fin, darkest in front at a postscapular spot. Below this band,
yellow. Fins unspotted. Total length .071 m.; to dorsal fin (ob-
lique) .03 ; to caudal (straight) .053 ; to ventrals (oblique) .032 m.

This species is near the type S. erythrops, Cope (Proc. Am.
Phil. Soc., 1870, p. 562, fig. 5), but has larger scales and a different
coloration. The genus Stethaprion has the physiognomy of My-
letes, but is essentially near to Tetragonopterus. It differs from
the latter chiefly in the decurved spine in front of the dorsal fin,
a character it shares with Serrasalmo.

BRYCON CAPITO, Cope, sp. noy.
Scales small, L. 1. 56, 1. tr. 25. Depth of body one-fourth,
length of head one-third of total without caudal. Radii D. 10;
1872. ] PART I1I.—18

262 PROCEEDINGS OF THE ACADEMY OF

A. 25; V.7(8?). Dorsal originating a little behind line of ven-

tral, pectoral reaching ventral. Orbit 2.66 times in head, equal

interorbital width. Middle series of premaxillary teeth continued

outwards as far as the exterior. Posterior pair of mandibular

teeth very small. Color leaden, head silvery, a scapular and

large basal caudal black spot. ;
Total length .06 m., to dorsal fin .0275, to anal .034.

CHALCEUS MACROLEPIDOTUS, Cuvier.
Cuv. Val. xxii. 240. Giinther, Cat. B. M. vy. 333.

Two teeth only in posterior mandibular series.

CHALCEUS ERYTHRURUS, Cope.
Plethodectes erythrurus, Cope, Proc. Am. Phil. Soc., 1870, p. 563, fig. 6.

This species belongs to Chalceus, but differs from the type in
having scales of equal size. Gunther says of this genus in his
analytical key, ‘‘ anal fin more or less elongate,” as distinguished
from “anal short” of Piabucina, yet C.macrolepidotus has as
many anal radii as P.erythrinoides. Creagrutus, with a fin of
about the same length, is placed in the “ elongate” anal division.

MEGALOBRYCON MELANOPTERUM, Cope, sp. nov.

Rather stout; dorsal outline arched. Length of head three and
three-fifths times in total lacking caudal fin, depth three times in
same. Orbit large, equal muzzle, 3.5 times in head. Radii D.11;
A. 25; V. 8, commencing opposite the third or fourth dorsal ray.
Pectoral just reaching ventral. Scales 1.1. 67, exposed surface
striate. Interorbital width 1.6 times diameter of orbit, gently
convex, less than postorbital length of head. Premaxillary teeth
in three series, the outer small, not in contact, equal to the maxil-
laries, and simple or with a minute cusp on each side; ten in
number on each bone. The posterior series is uninterrupted from
side to side, including six teeth on each side; the median row
forms an open AA, the angles forwards. Caudal fin deeply forked.

Total length seven inches, = m..176; length to dorsal fin .071 m.
(straight); to anal .10 m. Color silvery, with a black band which
commences between the ventral fins, on each side of the base of
the anal, across the caudal peduncle, and along the middle of the
upper lobe of the caudal fin to its end; anal black at base, other

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. 263

fins white. A black scapular spot, and a crimson spot at the apex
of each operculum. Opercular bones with purple reflections.
The Ambyiacu.

This genus was proposed by Gunther, in 1869 (Proc. Zool. Soc.,
p. 424), on the type species, MW. cephalus. This fish is evidently
nearly allied to the speciés here described, but is different from
them in the larger size of the external series of premaxillary
teeth, since they are, according to Gtnther, double the size of
the maxillaries, nearly in contact, and apparently more denticu-
late. Itis about as stout as the present fish, but the arrange-
ment of the posterior series of teeth is similar to the IZ. erythrop-
terus. I have two specimens of the JL. melanopterus, and they
agree in every detail.

MEGALOBRYCON ERYTHROPTERUM, Cope, sp. nov.

More elongate; length of head equal depth, and one-fourth the
leneth without caudal. Orbit large, 3.5 times in head, 1.8 times
in interorbital width. Radii D. 11; A. 23; V. 8, commencing op-
posite a point equal to five radii in front of the dorsal fin. Pec-
’ torals 12, not reaching ventrals. Squamation injured, lateral line
estimated 70. Teeth similar to the last, except that there are
twelve premaxillaries on each side, and that those of the posterior
row at each end, instead of being continuous with the larger me-
dian teeth of that row, are continuous with the lateral limbs of
the median M-shaped row, as in J. cephalus.

Total length 73 inches, = .19 m., to dorsal fin .086 m., to anal
115. Color pale and uniform, with a black scapular and large
basal caudal spot, which is prolonged as a band to the margin of
the fin. Rest of caudal and all the other fins, except base of dorsal,
crimson. Sides of head with pearly purple reflections.

Though the characters separating these species are few, they
are important. They are found in the form of body, position of
dorsal fin, anal radii, color, and dentition.

From the Ambyiacu.

TRIPORTHEUS, Cope, gen. nov.

Dorsal short, anal elongate. Teeth in three series on the pre-
maxillary bone, denticulate, in two rows on the mandible, the
posterior of the latter consisting of two convex median teeth.
Pectoral region compressed and keel-shaped on account of the
1872. ]

264 PROCEEDINGS OF THE ACADEMY OF

development of the coracoid bones; abdomen compressed. Dorsal
fin behind the line of the ventrals.

This genus has a considerable resemblance to Chalcinus, and
is intermediate between it and Chalcinopsis, Kner. The former
has two series of premaxillary teeth, the latter four; the present
possesses three. The Chalcinopsis alburnus, Gthr., probably be-
longs to T’riportheus.

TRIPORTHEUS ALBUS, Cope, sp. nov.

Teeth of the premaxillary closely packed, many denticulate ;
chin projecting beyond muzzle when the mouth is closed. Radii
PD. 11; A. 27; ventrals longer, extending to beyond the last ray
of the dorsal. Pectorals falcate, not quite reaching end of ven-
trals. Caudal deeply emarginate. Scales large 1. 1. 28, five series
above the lateral line. Head 3.5 times in length without caudal;
orbit large, exceeding interorbital width a little, and three times
in length of head (including chin).

Color dark ashen above, sides and below silver-white; a dark
spot at basis of caudal fin. Total length m. .061; length to
basis of dorsal fin .0292; from D. I. to basis caudal .02. The
dorsal outline of this species is regularly arched.

From the Ambyiacu.

TRIPORTHEUS FLAVUS, Cope, sp. nov.

Premaxillary teeth spaced, the anterior series in contact only
exteriorly. When the mouth is closed the chin projects but little,
and the profile of the head descends obliquely from that of the
back. Latter gently arched. Radii D. 11; C. 20; A. 30; V.7;
P. 11. Ventrals short, scarcely reaching the line of the last
dorsal ray, pectorals sometimes attaining that point. Caudal sub-
truncate. Head one-fourth length without caudal, eye 3.25 times
in head, equal interorbital space .75 times in muzzle. Depth at
ventral fin three times in length. Scales at ventral 6-34-5-3.

Total length 6.25 inches, = .157 m. Length to D. I. .08, to anal
.093; to caudal .132; depth at pectoral .044. Color brownish-
yellow, with golden reflections; four shaded lines above on the
middles of the scale series; above with steel-blue reflections; a
black band through the middle of the caudal.

Numerous specimens. In a young one of three inches the
caudal fin is deeply fureate, as in C. albus; perhaps in larger speci-
mens of the latter the tail is also subequal.

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. 265

CHALCINUS CULTER, Cope, sp. nov.

An elongate species, with very posterior dorsal fin. Height at
pectoral fin 4.33 times, at ventral five times, in length without
eaudal fin. Head 3.75 times in the same; orbit 3.8 in head and
1.2 in interorbital space. Head above flat in one plane from end
of muzzle to dorsal fin. Teeth small tricuspid, those of exterior
row not in contact with each other. Dorsal fin short, its last ray
opposite first anal; distance from base of caudal a little more
than half distance from end of muzzle. Pectorals falcate, reach-
ing nearly to line of dorsal. Radii D. 11; C. 19; A. 33; V. 8; P.
11. The inferior caudal rays are shorter than the median and
superior; ventrals reach to line of dorsal. The operculum is
nearly as long as high. Scales 740-3.

Color pale golden; head silver, the upper part of the operculum
with steel-blue reflections, bounded by a groove. A round black
spot on base of median caudal rays.

Total length .158 m.; length to dorsal fin .087, to anal .098.

This species is nearest the C. nematurus, Kner, but differs from
it in many important respects.

GASTEROPELECUS STELLATUS, Kner.
Denkschr. Ac. Wiss. Wien., 1860, 17 Tab. I. f. 2; Giimther, Catal. B. M.
v. 343.
REBOIDES MYERSII, Gill.

Proc. Ac. Nat. Sci. Phila., 1870, p. 92.

D. 11, A. 52; scales 22-83-22. Head 3.4 times in length. Prof.
Gill does not give the number of scales in his description, and
our fishes differ from his in the less depth, which enters the length
2.7 times instead of 2.5, and the larger eye, which enters the head
three times instead of 3.5 times.

REBOIDES RUBRIVERTEX, Cope, sp. nov.

Radii D. ii, its anterior rays 1.2 times as long as the head;
A. 51. Depth 2.66 times in length, length of head four times in
same. Scales 27-88-19. Ventral fin reaching anal, pectoral not
reaching end of ventral. Length from dorsal to near end of adi-
pose equal from same to end of muzzle (much less in R. myersii).
Profile gently concave above, dorsal line very convex; top and
sides of head rugose. Exterior teeth 3 above, 4 below; mandi-
1872. |

266 PROCEEDINGS OF THE ACADEMY OF

bulars in one row, with four canines. Two rows of premaxillaries,
the posterior wanting medially. In &. myersii the middle row of
teeth is so curved as to be continuous with the posterior series.
Scapular and caudal spots indistinct ; general color pink. Top
of head, maxillary bone, and opercula crimson ; fins immaculate.
Total length .135 m.; length to anal .059; to adipose dorsal .098;
to first dorsal .057. This is a larger fish with a smaller head
than the Rk. myersii. It may possibly prove to be the R. affinis,
Gunth., Pr. Z. 8., Lond., 1868, 246, but he describes “anal rays
55, scales 1. 1. 80,” and the dorsal fin appears to be more posterior.

ANACYRTUS SANGUINEUS, Cope, sp. nov.

A stout species with large scales. Sc. 12-54-12; radii, D. 9;
A. 43; V. 8, reaching anal; P. 16, to middle of ventrals. Back
much elevated, dorsal commencing in front of anal (A. i. op-
posite D. 4), and nearer end of muzzle than basis of caudal by a
little. Caudal deeply forked. Depth 2.6 times in length (caudal),
and length of head 3.4 times in the same. Eye four times in
length of head in adults, equal interorbital width. Operculum
and orbital bones rugose.

Premaxillary teeth in two very distinct series, a canine at the
inner, and one at the outer extremity of the bone. Maxillary
toothed to the end, which is behind the line of the posterior
margin of the orbit. Mandibular teeth with two (or three on one
side of one) canines on each side.

Color pale, with a large black spot on the line from the front of
the dorsal fin; a large black spot at base of caudal fin, from
which a faint line extends towards the former spot. Sides of
head with purple reflections. Dorsal, adipose, caudal, and anal
fins vermilion, the anal with a black border. Total length .133 m. ;
to basis dorsal .0626; to basis ventral .045; to adipose .10; to
basis caudal fin .115.

This brilliantly colored fish is nearest the <A. tectifer, Cope
(Proc. Am. Philos. Soc., 1870, 565), and A. pauciradiatus, Gthr.
(Catal. B. M. v. 346). It is less elongate than the former, and
has a more concave profile; the anal rays are more numerous.
From the latter species it is well distinguished by its well-defined
exterior premaxillary series of eight teeth, and the more anterior
position of the dorsal fin.

Numerous specimens from the Ambyiacu.

‘ [January 16,

NATURAL SCIENCES OF PHILADELPHIA. 267

XIPHOSTOMA TDO, Cope, sp. nov.

D. 10, A.10; scales of lateral line 75. Last dorsal ray above
the fifth anal. Head (without membranous flap) three times in
length to basis of caudal; eye 7.6 times in length of head, of
which four times enter muzzle (without flap); flap equal one
diameter of eye; interorbital space flat, 1.75 times diameter of
orbit. Muzzle flat above, decurved, receiving the mandibular
teeth within it, striate rugose. Teeth minute, equal. <A rudi-
- mental dermal flap on mandible. Pectoral fins reaching less than
.3 distance to ventrals; rays 15; V.8; extending half-way to
anal. Caudal emarginate. Depth of body at ventrals 7.75 times
in length without caudal.

Color light brown above, below white; two series of small
brown spots on each side, above. Top of head rosy; dermal flap
of muzzle vermilion, black-edged. Opercula golden, suborbital
bone with purple reflections. Dorsal fin yellowish, with two brown
cross-bands; anal with a median black spot. Caudal fin with
middle and tips black, margin and space between, with rays,
white.

Total length .203; to orbit .036; to ventral .112; to dorsal
-1382; to anal .1432; to caudal fin .178.

Two specimens from the Ambyiacu.

MYLETES ALBISCOPUS, Cope, sp. nov.

Discoidal, with small head ; anal rays long, the fin half covered
with scales. Radii D.17; A. 36; V.7. Caudal fin subtruncate.
Scales small, 41-100-45. Forty-seven spines in front of the anal
fin. Profile scarcely concave, orbit 3.5 times in head, a little less
than half the superficial width of the very convex interorbital
space. Length of head 3.75 times in total, lacking caudal; depth
1.4 times in same. Anterior teeth separated from posterior.
Pectoral fin to ventral, ventral commencing under dorsal. First
ray small, not reaching vent. Length .16 m.; to line of dorsal
(axial) .065; to line of anal (axial) .09; to caudal .125.

Color silvery, with blue reflections above, and golden below. A
black spot on posterior edge of operculum; otherwise immaculate.

Numerous specimens from the Ambyiacu. Two from the Per-
kins collection lack the opercular spot.

1872. ]

268 PROCEEDINGS OF THE ACADEMY OF

MYLETES OCULUS, Cope, sp. nov.

Premaxillary series of teeth in contact. Radii D.15; A. 24;
V. 7, reaching the vent, and commencing below the first dorsal
ray. Pectorals reaching base of ventrals. Preanal spines 43.
Form stout ovate, dorsal and ventral curvatures equal. Depth
1.75 times in length without caudal; length of head 2.5 times in
same; caudal fin bifurcate. Orbit 3.3 times in length of head
(of an individual .065 m. long), 1.75 times in the rather flat inter-
orbital space. Profile concave, operculum rugose. Depth of above
individual .0275 m.; length to dorsal fin .03; to anal .037.

Color dark plumbeous, with a black spot with a wide white
bordering ring just above the lateral line below the anterior part
of the dorsal fin. Many specimens with vertical dark, shades or
fasciee. Anal fin blood-red, black at base.

This species is well distinguished by its stout head and jaws,
and especially the ocellus on the side. The details do not agree
with those of any described species.

MYLETES HERNIARIUS, Cope, sp. nov.

Form subquadrangular or broad diamond-shaped from the
angular elevation of the back, and the abrupt prominence of the
abdomen. The thoracic outline is concave below the pectoral
fins. Radii D.18; A. 32; ventrals reaching vent, not attained
by the small pectorals. Abdominal spines of unusual length,
spine-shaped, 46 in number. Depth 1.4 times in length without
caudal fin; length of head three times in same. Orbit (in indi-
vidual of .05 m. in length) 2.6 times in head, less than the slightly
convex interorbital space. Profile concave; chin and muzzle pro-
jecting. Plumbeous above, silver below ; a very few small dusky
dots ; anal fin blackish.

Length to dorsal fin (of above individual) .022; to anal .027;
depth head at preopercular angle .01 m.

The very prominent abdominal saw, and spine-like form of its
teeth, distinguish this species. 'Two specimens.

SERRASALMO IRIDOPSIS, Cope, sp. nov.

D. 15-6; A. 34; abdominal spines prominent, forty-one. Depth
of body one-half length without caudal fin; length head a little
greater than one-third the same. Orbit 3.8 in head, a little less

[January 16

NATURAL SCIENCES OF PHILADELPHIA. 269

than interorbital space. Ventral fin originating opposite front of
dorsal; not reaching vent; pectoral reaching ventral. Bones of
head striate. Caudal fin openly emarginate. Color pale fawn-
color above, below silvery; four longitudinal series of round
black spots above lateral line; several scattered spots below it.
Opercular apparatus brilliantly colored; upper part of preoper-
culum and orbital bones green; middle golden, lower part purple
and violet. Operculum purple above, vermilion below; interoper-
culum vermilion; anal fin the same; caudal brown, edged with
pale yellow centre.
Total length .104 m.; to dorsal .0535; to ventral .0475; to anal
0615; to caudal .084.
This brilliant species is especially peculiar in the number of its
abdomino-thoracic dentations.
From the Ambyiacu.

SERRASALMO ESOPUS, Cope, sp. nov.

Radii D. 16; A. 32; V. 7; pectoral falcate reaching basis of
ventral. Form short, deep, dorsal curve greater than abdominal.
Depth 1.66 times in length without caudal, length of head three
times in the same. Scales 47-83-36; ventral spines 31. Muzzle
very short, only half as long as diameter of bony orbit, which is
contained four times in the length of the head, and twice in the in-
terorbital space. Latter convex transversely. Lateral line slightly
decurved in the middle. Dorsal fin nearer the base of the caudal
(first fulcrum) than the end of the muzzle, by the length of the
latter and half the diameter of the orbit.

Color bright yellow, unspotted, except a shade behind the epi-
clavicle. Caudal fin with a yellow margin and black band within
it; anal fin with a dark margin.

Total length .147 m.; to dorsal fin .075; to ventral .065; to
anal .088; depth at orbit .028; at first anal ray .073.

From the Marajion between the mouth of the Rio Negro, Brazil,
and the Huallaga, Peru. Robert Perkins.

SILURIDA..

PSEUDORHAMDIA PISCTARIX, Cope.
Proceed. Am. Philos. Soc., 1870, 569.
This species presents slight differences in the size of the orbits

and relative slenderness of the body, not dependent on age.
1872. ]

270 PROCEEDINGS OF THE ACADEMY OF

PIMELODUS LATERISTRIGA, Mull. Trosch.

Giinth., Catal. v. 118.

Differs somewhat from Gunther’s description, 7.e., in the longer
beards and one soft ray less in dorsal and anal fin. Radii D. I.
6, A. 11, V. 6. Maxillary barbels reaching to three-fourths the
length of the adipose fin; exterior mentals to end of pectorals.

DORAS GRYPUS, Cope, sp. nov.

Lateral shields twenty-eight, short vertically, and furnished
with a single strong reverted spine. ‘Tail shielded above and be-
low from opposite the twenty-first. Head broad, flat above, with
a short concavity in the position of the fontanelle. Casque broad,
obtusely roof-shaped, sending a process back on each side the
dorsal fin. Body slender. Pectoral spines very powerful, reach-
ing to beyond dorsal fin (in two specimens), with strong serra-
tions. Dorsal spine strong, longitudinally striate, not serrate.
Postclavicular process long and strong, reaching as far as the
process of the casque, with an external row of teeth, which are
proximally in a groove. Humeral process of coracoid swollen
laterally, striate grooved. Top of head rugose. Diameter of
eye five times in head (to edge bony operculum), twice in interor-
bital space, once in muzzle. Preorbital bone with an obtuse ver-
tical ridge. Length of head 3.66 times in length to basis caudal
fin, greatest depth 4.2 insame. Radii D. I. 6; C. forked, 15; A.
12; V. reaching to anal 8; P.I. 6. Postcoracoid processes short,
smooth, maxillary barbels to middle of pectoral spine.

Color above black, below light brown black-dusted, gular region
yellowish. A yellow band on side, margined below by three broad
longitudinal black bars. Caudal fin black, yellow medially, anal
and dorsal fins black in front, yellow posteriorly ; ventrals yellow,
with two black cross spots.

Total length 5 inches, = 0.1264 m.; width at humeral swellings
036 m.

This species exceeds many others in the relative size of the
Spines and casque.

DORAS BRACHIATUS, Cope, sp. nov.
A rather large species, of slender form, with smooth front, and
very large pectoral spines. Lateral scuta forty, low, flat, and
wide, with a flat reverted spine on the middle, the posterior edge

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. Orel

with three or four serrations near the extremity; three opposite
the dorsal fin much elevated, two in front of them small, spine-
less Radin D.718 63 Cy -Fat-p ALTE Vo Ty Pok.c8) \Dorsal
spine very strong compressed, with teeth pointing downwards
behind and upwards before; its length one-half length of fish an-
terior to it. Pectoral spine flat, striate, with strong teeth on
both faces, the posterior the longer. Eye looking partly upwards,
covered with rather thick cornea 8.5 times in length to bony oper-
cular margin, a little less than half interorbital width. Muzzle
flattened and narrowed, the maxillary beards leading to the mid-
dle of the humeral process, the mental beards half as long.
Rugosity of the casque striate, bifurcating at the fontanelle, and
sending an angle to the front of each orbit, and then ceasing. A
weak serration of the small preorbital bone visible. Head flat
between the orbits, the casque steeply roof-shaped, contracting
and then expanding downwards opposite the dorsal spine, but
not exceeding it. Humeral spine extending to opposite dorsal;
flat, striate ; postcoracoid short, covered with smooth skin. Ven-
tral fin commencing some distance behind last dorsal ray, obtuse,
not reaching vent, but reached by the pectoral spine. Caudal
peduncle short; caudal fin deeply furcate. Adipose fin well de-
veloped, but low. Teeth numerous, brush-like.

Total length .382 m. Length to eye .037; to dorsal spine .12;
to ventral fin .165; to anal fin .222; to basis of caudal fin .31.
Width at humeral swellings .077; height at basis D. I. .095.

Colors bright; above brownish, sides pink, below white. Fins
red, except pectoral and dorsal, which are paler.

This marked species is very different in general physiognomy
and details from such short, rough, black species as D. pectinifrons
and D. grypus, being elongate in form, and smooth, though well
armed. Discovered by Robert Perkins between the mouth of the
Rio Negro and the Huallaga, in the Maranon.

ZATHORAX, Cope, gen. nov.

Proc. Acad. N. Sci. Phila., 1871, p. 112.

Branchial fissure much contracted. Lateral shields not meet-
ing on the middle line of the back. No adipose fin? dorsal and
anal fins short. Spines and postclavicular process strong. Ven-
trals behind dorsal. Scapular arch dilated below and covered

with a dermo-ossification.
1872. ]

272 PROCEEDINGS OF THE ACADEMY OF

This genus is Doras with the expanded dermo-ossified sternal
shield of the following genus Physopyxis. It forms a group con-
necting the two, and differing from the latter in not having the
lateral scuta meeting on the dorsal line. In one specimen there
is no adipose fin, ina larger there is arudiment. As in Doras, the
postclavicular process is more extensively developed than the
postcoracoid, while in Physopysxis the latter is developed at the
expense of the former. The Zathorax monitor constitutes speci-
fically a link between such Dorades as D. grypus and the Physo-
pyxis lyra, in being of stouter form than the former, but less squat
and toad-like than the latter. It has the comb-like preorbitals of
the latter.

Only one species is known.

ZATHORAX MONITOR, Cope, sp. nov.

Twenty-five short lateral scuta, each with one strong recurved
median spine. Casque broad, furcate to receive the dorsal fin,
obtusely roof-shaped to between the orbits, where it is a little
concave, weakly rugulose and striate. Preorbital bones with 12
processes above, not dentate on the lower margin. Muzzle broad,
short, lips even, mouth reaching to opposite front of preorbital.
Beards on the chin normal. Maxillary barbel reaching to poste-
rior margin of orbit, but possibly further in a harder specimen.
Orbit 3.75 times in head, 1.66 in interorbital width; head 3.75
times in length without caudal, twice to third lateral scutum.
Greatest depth (at dorsal spine) 3.5 in length. Postclavicular
spine extending to line of posterior process of casque, furnished
with a row of distant strong teeth on the outer edge. Humeral
swelling enlarged laterally, giving unusual width to this region.
Postclavicular spine short, acute, sternal shield transversely
striate, twice as wide as the gular region in front of it.

Radii D. I. 6, the spine trigonal, straight, not serrate before or
behind, but striate; C. 714; A. 12. P. I. 6, the spines large,
reaching beyond end of ventrals, with numerous close-set teeth
or spines on both edges, and a terminal one; surface striate.

Total length .038 m., width at shoulders .013 m., at canthus oris
0053. Length dorsal spine .008, of head and casque .016. The
larger specimen is .052 in length.

Color destroyed by the action of the spirits; pale brown, the
pectoral spines dark-spotted.

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. 273

PHYSOPYXIS, Cope.
Proceed. Acad. Nat. Sci. Phila., 1871, 112. Genus novum doradi affine.

Dorsal fin with strong pungent spine, in advance of the ventrals.
Gill openings much reduced, opercular apparatus attached to
clavicular arch below. No adipose dorsal; anal fin short; vent
median; nares close together, the posterior minute. Barbels well
developed, one maxillary and two mental on each side. Mouth
terminal, teeth minute in several series.

Sides and dorsal part of the body entirely inclosed by vertical
osseous shields. Head and thoracic region inclosed in a trihedral
osseous box, composed of the expanded cephalic casque above,
clavicular arch laterally, and the immense development of the
clavicles and coracoids inferiorly. These form a shield, which
extends to beneath the eyes anteriorly, and sends two postcora-
coidea posteriorly, all entirely involving the derm. Pectoral
spines and swim-bladder greatly developed.

This strange genus carries to its highest extreme the peculiar
features of Doras. Thus the branchial fissures are still more re-
duced, the operculum being attached all along its inferior margin;
the lateral osseous dermal scuta are prolonged upwards to the
median dorsal line; the pectoral spines are immensely developed.
It differs further from Doras in the greater development of the
inferior elements of the scapular arch and the entire occupation
of the skin by the ossification. The swim-bladder is large, and
extends to the skin on each side of the casque and above the
humeral processes, and between the long postcoracoid processes
on the inferior surface. The osseous box inclosing the anterior
half of the body protects this swim-bladder, but the teleologist
will suggest that perhaps, on the other hand, the large swim-
bladder is necessary to float the heavy shields and defensive
spines.

The small body and immense casque give this form a very pe-
culiar appearance, and suggest a miniature iron-clad with mast
and outriggers.

PHYSOPYXIS LYRA, Cope, sp. nov.

Muzzle short and broadly truncate, about as long as the dia-
meter of the eye, lips even. Interorbital region concave, thrice
as wide as the diameter of the orbit, with an oval median fonta-
1872. ]

274 PROCEEDINGS OF THE ACADEMY OF

nelle. Orbit 4.2 times in length to opercular margin. The casque
rises from the orbits to the dorsal spine. It is keeled obtusely,
or roof-shaped, extends on the sides nearly to the lateral line, and
is prolonged into a point on each side of and behind the last ray
of the dorsal fin. The humeral portion of the clavicle is much
enlarged and dilated horizontally, and is produced into a post-
humeral (postclavicular) spine which extends to below the dor-
sal spine, is sharp-edged, striate, and not serrate.

The inferior aspect of the scapular arch is a transverse shield,
convex in front, concave behind, and gently concave inferiorly,
two-thirds of its width being composed of the coracoids; the sur-
face punctate. The postcoracoid processes are very long, ex-
tending to beyond the bases of the ventral fins; they are curved,
and the extremities dilated outwards, so as to present with the
thoracic portion exactly the form of the Grecian lyre. ‘The huge
prickly pectoral spines curving round on each side, and meeting
behind the ventral fins, suggest the wreath which often accompa-
nies the lyre. The surface of the postcoracoid processes is longi-
tudinally striate. A section of the fish in front of the pectoral
fins is triangular.

The preorbital bones are well developed; they form an erect
transverse crest of eleven long, sharp teeth, and are toothed late-
rally and below. Casque rugulose.

Radial formula D. I. 4, C. 12, A. 12; V.6; P.I.2. The dorsal
spine is quite straight, trigonal in section, and longitudinally
erooved. The inferior half in front is furnished with stout spines
directed upwards; behind smooth. The pectoral spines are very
large, curved, and extend to the second or third ray of the anal
fin. They are spinous, and longitudinally grooved.

The lateral shields are twenty-three in number, and each is fur-
nished below its middle with a recurved spine as in Doras. The
surface of the plates is granular. Caudal fin truncate.

Color in front of the dorsal fin dark brown, minutely varied
with lighter; a light cross-band from one humeral base to the
other, and another between the orbits. Posterior part of the
body yellowish, with a dark spot at the base of the dorsal fin; a
band on the middle of the side, and one at the base of the tail.
Fins brown-dusted; dorsal and pectoral spines brown, yellow
cross-banded. Inferior surfaces deep brown, except the osseous
portions, which are pale brown.

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. 275

M.
Total length . : , : : ‘ : : . 0.035
Length to orbit : ; Z : ‘ : , . .0015
“SS opercular shit P ¢ : : ‘ 20 00%
OU CCopyexaingz Laivay So : ‘ ; : ; 2 OWS
Seecoeamelctin j : ; : : : . .0189
e ** caudal fin 3 ‘ : . , . L028
‘* of dorsal spine . F F : : : . 0075
se * “pectoral spine 4 : : : : . 0128
se ** nostcoracoid : : : , : . .0082
Width of muzzle . j : ; : : : . .005
‘* at humeral knobs : 3 . : 3 O18
key S*listlateraleshield, ) +- : ‘ : ‘ . 008
Expanse of both pectoral spines. : : : 5 ABH

Ambyiacu River, Equador. John Hauxwell.
The preorbital comb is like that of Doras pectinifrons, Cope,
from the same region.

CALLICHTHYS ASPER, Q. Gaim.

Ginther, v. 225.

CALLICHTHYS MELAMPTERUS, Cope, sp. nov.

The head depressed, muzzle broadly rounded. Body strongly
compressed ; the dorsal line rising steeply and continuously with
the profile, to the dorsal fin. Caudal region much compressed ;
tail openly emarginate. Inferior lip little reverted, bearing no
barbels; tip of the muzzle projecting but little beyond the mouth,
Inferior barbel extending to near the end of the ventral fin, supe-
rior to near the end of the pectoral. Lateral shields 25-24, from
supraclavicle. Azygous plates 5. Radii D. 8, A. 1,6, V. 7, P.
I. 8. Dorsal spine like other rays, pectoral toothed within, and
with short tooth-like bristles without. Spine of adipose reaching
to basis of caudal.

Orbit 3.5 times in length of head, twice in interorbital width.
Depth of head more than two-thirds length. Length of head one-
third length without caudal, equal depth. Length over all, three
inches.

Color dark plumbeous; the preorbital region, and caudal and
inferior fins, black.

This species is much more compressed than the C. asper. Be-
sides other points, there is one more pectoral ray and a different

1872.]

276 PROCEEDINGS OF THE ACADEMY OF

coloration from the C. knerii, Gill, from Trinidad, W. I. Nu-
merous specimens.

DIANEMA, Cope, gen. nov.

Allied to Callichthys. A single barbel at the extremity of each
maxillary bone; two barbels at the symphysis of the mandible ;
teeth minute, brush-like. Body shields in two series, as in
Callichthys ; postcoracoids dilated into two shields which meet on
the median line and involve the derm, as in Hoplosternum. Sides
of the face not shielded ; parietal not reaching base of dorsal fin,
but separated by two transverse shields of the sides. Dorsal and
pectoral fins with powerful spines, caudal subtruncate. Adipose
fin present, pungent.

This new genus, it will be seen, combines in an interesting
manner the characters of Hoplosternum, Gill, Brochis, Cope, and
Corydoras, Lac. The shielding is of the first, and the fin radii of
the last two, while in the peculiar barbels it resembles no other.
The relation of these to the double maxillary barbels of Corydoras
appears to be explained by the structure in the genus Brochis,
and will be mentioned under that head. |

DIANEMA LONGIBARBIS, Cope.

Form rounded compressed; head depressed, wide, but abruptly
narrowed in front of the nares. Maxillary barbels not reaching
the opercular margin, mental to the middle of the pectoral fins.
Shields 25-24, azygos four, all nearly smooth. Radii D. I. 7 L,;
C.125 A. 7; V. t; P.1.6.. The pectoral spine is‘ lone and
straight, terminating in a point, and is finely and strongly serrate
on the inner, and finely bristled on the outer faces. Dorsal spine
acute, not serrate. Length of head 3.66 in length without caudal
fin, equal depth at dorsal fin. Postorbital width equal .70 length
of head, width at nares equal length from muzzle to orbit; orbit
3.75 times in head, 2.5 times in interorbital width. Total length 34
inches, or .09 m. Color light yellowish-brown, fins unspotted.
The specimen has, however, lost all coloration it might have had,
in the spirits.

The dorsal spine is less developed than in the species of Cory-
dorus. The posttemporal region is perforated by a few pores.

[January 16,

NATURAL SCIENCES OF PHILADELPHIA. 277

BROCHIS, Cope, gen. nov.

Allied to the last genus. Two barbels at the extremity of the
maxillary bone, united by a beard-like looped cord to the sym-
physis mandibuli, the cord being thus attached at both ends.
Teeth rudimental or wanting. Body with two longitudinal series
of shields, the postcoracoids expanded and meeting on the median
line. Head compressed, the parietal shield only separated from
the dorsal spine by the basal azygos shield of the latter. Sides
of head shielded to the mandibles. Dorsal and pectoral fins with
strong spines; adipose present, purgent. Caudal fin emarginate.

This genus is allied to Corydoras, but differs from it as Hoplo-
sternum does from Callichthys with the addition of the peculiar
pendent dermal loops of the mandible. These loops are confluent
at the symphysis mandibuli, and from that point to their union
with the maxillary barbels resemble exactly the mental barbels of
Dianema. It is difficult to avoid believing that these loops are
homologically the recurved inferior lips of Corydoras, separated
from the greater part of the ramus, but joining again at the can-
thus of the mouth and giving rise to the inferior barbel. It then
follows with much probability that this connection also is severed
in Dianema, and the inferior maxillary barbel remaining as before
continuous with the mandibular loop, becomes the mental barbel.
In the shielding of the head, Brochis is like Corydoras, while
Dianema is like Hoplosternum, so that the affinities are compli-
cated and not readily expressed by a linear arrangement.

BROCHIS COERULEUS, Cope, sp. nov.

Form short, stout, elevated, and compressed. Head steep,
gently convex above the orbits and concave above and below
them, and tapering to a very narrow muzzle, which overhangs the
mouth a little. Scuta, 23-21, smooth, with one oval supratempo-
ral shield only. Nares small, close to the orbits. One large com-
bined pre-and suborbital shield; a large subtriangular loreal plate.
Maxillary barbels extending to opposite the middle of the orbit.
Shields of the head, with the postcoracoids, slightly rugose.

Length of head one-third length without caudal fin, 1.33 times
in greatest depth at basis of dorsal. Orbit four times in head,
more than twice in muzzle, which equals the width of the convex
interorbital space. The dorsal outline is strongly arched, de-
1872. ] PART I11.—19

278 PROCEEDINGS OF THE ACADEMY OF

scending behind from the middle of the dorsal fin. Radii D. I.
11, I., without adipose portion; C.14; A. 8; V. short, 6; P.I. 9.
Dorsal spine moderate, serrate behind and smooth before, pectoral
stronger, finely but strongly serrate behind, smooth in front; it
extends to or a little beyond the middle of the ventral in all our
specimens. Length, three inches; depth, one inch.

Color of body and sides above, with sides of head, metallic
blue; below, yellowish. Fins unspotted.

This elegant species appears to be very common in the tributa-
ries of the Ambyiacu.

BROCHIS DIPTERUS, Cope, sp. nov.

This species is represented by a single specimen, which differs in
several points from the type of the genus. These are: Ist, the
existence of a well-developed adipose membrane to the adipose
fin; 2d, the existence of only ten rays in the first dorsal fin; 5d,
the thick attached inferior lip with two median beards. The
lateral shield of the muzzle is more completely united with the
surface of the ethmoid than in similar specimens of the JB.
coeruleus, but not more so than in larger specimens. Scuta 24
above. Pectoral and dorsal spines serrate within. Color and
proportions as in B. coeruleus, the added adipose fin having a
black border behind.

The characters of seven specimens of the type species are con-
stantly different from this one.

CORYDORAS, Lacep.,
Differs from Callichthys in the prolongation of the supraoccipital
shield upwards between the lateral shields to near the base of the
dorsal ray, and in the possession of strong dorsal and pectoral
spines.

The species of this genus are referred to a section of Callich-
jrys by Dr. Gunther, which he characterizes by the compressed
form of the head. I think they constitute a natural genus char-
acterized as above, and would admit species having the above
peculiarities into it, no matter what the form of the head. The
new species here described, however, agree with those already
known in this compression of the head and body. The genus
differs from Lrochis in the non-shielding of the intercoracoid re-

[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 279

gion, and of the sides of the muzzle, these regions being inclosed
by membrane only.

One species, C. semiscutatus, Cope, has the postcoracoid pro-
cesses much widened and with a superficial rugose ossification of
the derm, thus approaching Brochis. The median portion of the
thorax is, however, not inclosed. The sides of the head are also
more fully ossified than in other species.

The typical species present interesting modifications of the in-
ferior lips. Thus, that of C. ambiacus is broadly reflexed, of
equal thickness, and furnished on its posterior border with two
short barbels. In C. trilineatus the lip is recurved, and without
barbels, but the margin is thickened into a cord, which is con-
nected with the edge of the mandible by a membrane so attenu-
ated as to be easily ruptured, when the arrangement resembles
closely that seen in Brochis. In the third group the inferior lip
appears to be entirely wanting. I add to the characters of the
four new species here described those of the three recorded by
Gunther, as far as I can learn them.

Group I.

Head longer than high ; barbels to middle of orbit; ‘‘A. 6.”’
C. PALEATUS.
Head higher than long; barbels to operculum; A. I. 6. Muzzle long;
dorsal spine moderate serrate; irregularly spotted. C. AmBIAcus.

Group II.

Muzzle short, convex; barbel to posterior edge of orbit; dorsal and anal
spines shorter, former smooth ; a light lateral band, divided and margined
by a black line. C. TRILINEATUS.

Group III.

Muzzle produced, acute, concave; barbel to middle of orbit ; dorsal and anal
spines short, former serrate; no azygus shields; uniform, with a pale
lateral band. C. AcUTUS.

Muzzle short, acute, concave ; barbels to middle of orbit; dorsal and anal
spines very long, former smooth; four azygus shields; olive, black-
dotted. C. AMPHIBELUS,

Group ? ?

‘*Head high as long; barbels to gill opening; A. 8.’’ CO. PUNCTATUS.

‘Similar to C. paleatus, but fins immaculate; A. I. 6.’? C. AENEUS.

‘“‘Head higher than long, muzzle short convex; barbels to below eye;
dorsal spine long, serrate ; anal short, four or five azygus plates ; anterior
scutes with vertical rows of black spots.’’ C. ARMATUS,

1872.]

280 PROCEEDINGS OF THE ACADEMY OF

CORYDORAS SEMISCUTATUS, Cope, sp. nov.

Radi, 1). T. 11, 1, no adipose. portion; A. 1. 6; V..620b. 1 ae:
Scuta 23 above, including postcephalic, no azygus shields. Pre-
orbital bone and shield single, large, extending half way from
orbit to maxillary, and downwards, .4 way to line of maudible.
Postcoracoid processes wide, with convex inner margins which
are separated by a wide fissure, the surface striate rugose, no
lateral shield separates them from the base of the ventral fins.

Profile steep, arched in front of nares; muzzle contracted,
pointed. Orbit 3.5 times in head, 1.66 times in muzzle and inter-
orbital space. Head 2.8 in length without caudal fin; depth 2.4
times in same. Inferior lip beaded on margin, which easily
separates, forming a loop; no median barbels visible.

General color above pearly or nacreous-blue, with metallic re-
flections on postclavicle and operculum.

This species shows a marked tendency to the genus Brochis in
the increased extent of the osseous shields of the thorax and
sides of the head. The enlarged number of dorsal fin rays is an-
other indication of such affinity. It represents very closely, I
have no doubt, a young stage of Brochis cwruleus in the incom-
pleteness of the shield development, and might, by some, be re-
garded as that animal itself. Specimens of the latter of nearly
the same size betray no approach to it in characters, and experi-
ence elsewhere warrants the opinion that the parallelism will be
seen at a far younger age than any of our specimens represent.

CORYDORAS PALEATUS, Jen.

Callichthys paleatus, Jenyns Voyage Beagle Fishes, p. 118. Gimnther,
Catal. B. M. v. 230.

CORYDORAS AMBIACUS, Cope, sp. nov.

Form stout, compressed, dorsal line arched, front convex at
orbit, slightly concave on the elongate muzzle. End of muzzle a
little projecting beyond mouth, its outline gradually expanding
to orbit. Interorbital region transversely convex. Lower lip
widely reverted, its marginal barbels each shorter than the dia-
meter of the eye. Latter 3.33 times in length of head, 1.75 times
into muzzle and interorbital width. Length of head 3.2 times in
length without caudal fin, and 1.25 in depth of body.

Lateral shields 22-21; azygus shields one basal and one flat.

[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 281

Radii D. I. 7.A.1.6; V.6; P.I. 9, the spine acute, serrate on inner
side, reaching half-way along ventral. Anal spine short, weaker
than adipose dorsal spine. Latter with adipose appendage.

Straw color, with numerous indefinite brown spots on the sides.
Dorsal fin with a large black spot covering anterior half, which
also expands on the dorsal region round the base of the fin. Four
vertical brown bands on caudal fin; anal spotted. Cheeks with
blue reflections. Length .058 m.; depth at D. I. .018 m.

CORYDORAS TRILINEATUS, Cope, sp. nov.

This species is easily distinguished from the other species here
noticed, by the short, abruptly decurved muzzle, and three longi-
tudinal lateral lines.

The head is much deeper than long, and enters the length with-
out caudal fin 3.5 times, and the greatest depth 1.5 times. Orbit
2.75 in head, 1.5 in convex interorbital space. Lateral shields 21-
20; two highly keeled azygus. Radii D. 1.7; A.1.6; V.6; P.I.6,
the spine acute, without serrations; the dorsal spine serrate
throughout behind, not extending to the base of the adipose
spine. Latter much larger than anal spine, attached to an adipose
portion.

Light straw-colored, brownish above, a yellowish lateral band
with rather faint brown margin above and below, and blackish
median line. A very black spot on the ends of the soft dorsal
rays; tail deeply forked, with five vertical bands; anal spotted.
Some longitudinal lines on the side of the face. Length .049 m.,
depth .015 m.

The mouth in this species is quite inferior. The peculiar struc-
ture of the lower lip, which is a festoon supported by a thin mem-
brane, I have verified on two individuals. The thick margin on
each side bears a very short barbel.

CORYDORAS ACUTUS, Cope, sp. nov.

A stout species, differing from the others, especially in the at-
tenuation of the muzzle, which viewed from above is narrow, and
contracted abruptly from the general outline. Mouth inferior,
lower lip wanting or not reverted. Head 3.1 times in length
without caudal, 1.33 times in depth. Orbit three times in head,
1.33 times in the nearly flat interorbital space. Lateral scuta 22—
91; no azygus plates. Radii D.1I.7; A.I.6; V.6; P.I. 5, the
1872. |

282 PROCEEDINGS OF THE ACADEMY OF

spines serrate on the inner side. Dorsal spine serrate poste-
riorly on the distal half. Adipose spine without fin, stouter than
anal spine. Caudal fin furcate.

Color olive (faded), a faint pale band on each side; a large
black spot on distal part of dorsal rays. Caudal with four verti-
cal bars; clavicle and operculum with blue reflections. Length
-051 m., depth .0155 m.

CORYDORAS AMPHIBELUS, Cope, sp. nov.

A species much like the last, but differing in its longer spines,
short muzzle, and numerous azygus shields, etc. Form the stoutest
in the genus, profile descending steeply from the dorsal fin to be-
low the nares, then concave, and descending to the narrow muz-
zie. Head three times in length lacking caudal, 1.4 times in depth.
Orbit 3 times in head, 1.6 times in interorbital width. Lateral
shields 21-19, four flat azygus. Radii D.I.7; A.I. 6; V. 6; P. I.
6, the spine serrate within. Dorsal spine serrate posteriorly, elon-
gate, reaching the adipose spine when depressed. Adipose long
without fin, but shorter than the slender spine of the anal. Total
length .037 m.; depth .0124 m.

Color light olive, face with blue reflections. Numerous small
black dots on the side shields, which are only wanting on the
middle line of the side. Dorsal with a black spot on the ends of
its radii, and another at the base of its spine. Caudal with four
vertical cross-bars.

CORYDORAS PUNCTATUS, Bloch.

C. geoffroyi, Lacep. Callichthys punctatus, D’Orb. Cuy. Val. Gimnth. v.
229.

Surinam, Monte Video.

CORYDORAS ENEUS, Gill.

Hoplosoma eneum, Gill., Ann. Lyc. N. Y., 1851, p. 408. Callichthys, do.
Ginther, 1. c.

Trinidad, W. I.
I cannot learn the structure of the lips in this and the follow-
ing species :—
CORYDORAS ARMATUS, Ginth.
Callichthys armatus, Gthr., Pro. Zool. Soc., Lond., 1868, p. 230. Fig. 1.

Xeberos on the Huallaga, Peru.
[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 283

CORYDORAS SPLENDENS, Cast.
Callichthys splendens, Castelnau, Anim. Nouy. Rar. Am. Sud. 39, Tab. 18,
eee
Rio Tocantins.
OTOCINCLUS, Cope.

Proc. Acad. Nat. Sci., Phila., 1871, p. 112.

Subfamily Hypostomatina of Gunther’s system. Ventral fins
immediately below the front of the short dorsal; branchial fis-
sures extending a little below pectoral fins. Vent a little behind
the middle of the body. Body shielded with several series of
plates, the anterior less numerous. Thoracic and abdominal re-
gions with numerous shields. No adipose fin; dorsal with weak,
pectoral with strong spine. Inter-operculum horizontal, beneath
the orbit, unarmed. No barbels. The teeth as in allied genera.
Post-temporal region pierced with numerous foramina, forming a
sieve, which only separates the water from a large cavity on each
side of the modified anterior vertebra, by the thin skin which
covers it.

This genus is allied to Hypoptopoma, and apparently to Rhine-
lepis. The arrangement of the opercular bones is like that seen
in the former (see figure of H. bilobatum in Proc. Am. Phil. Soc.,
1870, p. 567), while the absence of adipose fin and general rugo-
sity are seen in the latter. Neither exhibits the remarkable per-
foration of the post-temporal plate. This is,in the only known
species, so extensive as to cover the whole plate to the orbit, which
becomes thus a skeleton sieve of some beauty, through which the
cavity within may be plainly seen. Its use is unknown, but may
be connected with the function of hearing, as the genus has no
swim-bladder.

OTOCINCLUS VESTITUS, Cope, sp. nov.

Body compressed, head elongate oval, neither elevated. Muz-
zle rounded-acuminate, projecting much beyond mouth, nareal
opening near orbit. Loreal region vertical, a canthus rostralis ;
muzzle a little convex between nares and orbits; profile gently
arched from dorsal fin to end of muzzle. Scales obtusely angu-
late behind, the exposed surface covered with distant elongate
prickles. Four rows on the caudal peduncle, the third from above
bearing some tubes of the lateral line, and becoming more elon-

gate and oblique anteriorly, until from the point of the pectoral
1872. ]

284 PROCEEDINGS OF THE ACADEMY OF

they occupy the entire inferior half of the side. The second
does not enlarge till near the postcephalic plates, where two or
three occupy the upper half of the side. Longitudinal line con-
taining twenty-one. Those of the superior and inferior series are
angulate near the margin of the peduncle, and meet on the supe-
rior and inferior median lines by a straight suture. Thus these
faces form distinct but slightly convex, narrow planes. Parietal
shield broader than long, postparietal large, its apex separated
from D. I. by two cross-shields, the first wider. <A large shield
on each side the postparietal. The whole of this region swollen,
greatest width of head at the sieve.

Orbit three times in head, twice in interorbital width; head 3.5
times in length, without caudal fin; depth 4.5 times in same.
Caudal fin well developed, deeply forked. Dorsal elevated in
front; radii I. 65 (C..17; Av Td; V. 1. 5; 3B. FE bs.the*spimemiat,
reaching the basal fourth of the ventrals, with short spines out-
side which become teeth at the end; within smooth. Scapular
arch rather narrow below, followed by three series of shields, of
which the lateral are long and narrow. These gradually diverge
and admit three series of small scales, which again diminish and
terminate in an obtuse point between the ventral fins. This leaves
with the ends of the lateral shields a Y-shaped naked space, at
the end of which is situated the vent. These are covered with
numerous short bristles, like the scales of the dorsal region. The
head, especially the muzzle, and more particularly the sides of
the latter, are covered with many short, closely set, spiny bristles,
which give the whole fish a hoary appearance when dry. Spines
of fins also hirsute. Teeth bristle-like, those of the mandibular
rami opposed to each other.

Yellowish-brown above, browner on the head, darkest on the
lores. Sides and below bright yellow, a weak dark shade on
lateral line, and large black spot at base of caudal. Fins un-
spotted. Total length .04 m.; length to anal fin .02; width of
head behind .007.

Tributaries of the Ambyiacu.

LIPOSARCUS VARIUS, Cope, sp. nov.
Radii-D. 1350s; 60.1. 14, 1) An 52 V4lobe Pie G. avorsal
longer than high, basis nearly equal length in front of it. Pee-

toral spine to middle of ventral; superior caudal ray shorter
[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 285

than inferior. Scuta 1.1. 28,1. tr. 4. Inferior regions granular ;
dermo-ossification of head extending to inferior plane all around,
Orbit small, three times in interorbital width, five times in head,
width a little greater than length. A marked canthus rostralis
to beyond nares; loreal region steep, concave. An occipital keel,
nuchal shields two-keeled. Elevation at latter, equal length
muzzle and orbit.

Scales rugose, with a serrate median keel ending in a point.

Above, brown; below, yellowish-brown, closely spotted with
dark brown, most coarsely on the belly, and finely on the head,
leaving vermicular interspaces; eight rows of black spots on the
dorsal fin. Other fins, except the caudal, closely black-spotted.

Length .18 m.; to anal fin .085; to mandible .01.

Numerous young specimens of this species, the largest .085 m.
in length, display the following characters of immaturity. The
inferior surfaces are smooth, and in the smaller the dermo-ossifi-
cation of the loreal region exists only in spots, and in still smaller
is wanting.

Two large specimens from Perkin’s expedition have the hume
ral width and the total length, the base of the dorsal fin enters
the same 3.75 times, and is equal the length of the pectoral spine,
aud the greatest depth of the body enters six times. The speci-
mens agree with Castelnau’s LZ. pardalis in having dorsal radii
1.12, but differ in having no keel on each side of the back poste-
rior to the dorsal fin, and in having large spots on the belly, not
“ puncte.” ‘The former character I derive from Castelnau’s figure
only.

The young of a second species of this genus occurs in the col-
lection. ;

PLECOSTOMUS BISERIATUS, Cope, sp. nov.

Radii D. I. 7; A.5; V.1.5; P.1I.6. Lateral series of scuta
28, three rows between ventral and dorsal fins. Elevation of first
dorsal ray equal length of head; length of basis equal to dis-
tance from spine of adipose, and 1.66 times length of head and
nape. Scuta between dorsals 8, between anal and caudal 16.
Pectoral spine to basis of ventral. Scuta not carinate, coarsely
striate, the strize terminating in a few small spines.

Head short, entering length without caudal fin 4.5 times, and
a little less than width. A postorbital and orbito-nareal angle,

rim of orbit elevated above front. An obtuse median occipital
1872. |

286 PROCEEDINGS OF THE ACADEMY OF

elevation, nuchal scuta not keeled. Orbits four times in head,
2.5 times in interorbital space. Muzzle regularly acuminate, a
triangular spot on extremity, smooth. Margins of muzzle not
spinous. Inferior surfaces rugose, except a smooth band sur-
rounding posterior lip, and a quadrate area within ventral fins.
Lip entire ; barbels short.

Inferior caudal ray one-quarter longer than superior, no long
bristles on it or the ventral.

Total length 1.55 m.; do. to dorsal fin .045; toanal ; hume-
ral width .07. Color yellow; below white, immaculate. Above
with three rows of ill-defined blackish spots at the unions of
scales, the inferior wanting behind the line of the dorsal fin.
Head above with many close brown dots. Dorsal fin with two
rows of blackish spots between each pair of rays; one series be-
tween the caudals. Twenty-eight teeth on each ramus mandibuli.

From the Amazon, from Robert C. Perkins. This species is
especially distinguished by its short head, and by the characters
of squamation of lower surface, color, etc.

PLECOSTOMUS SCOPULARIUS, Cope, sp. nov.
Proc. Acad. Nat. Sci., Phila., 1871, p. 55.

Is represented by a number of similar young individuals.
They differ in having a more slender muzzle, and dorsal radii II.
12, I. Ventrals also I. 5.

CHEATOSTOMUS, Tsch. Heckel.

There appear to be five nearly related species in the collection
from the Ambyiacu, and I cannot find that any of them have been
noticed by authors. Their characters may be summarized as fol-
lows :—

I. Muzzle naked, D. I. 7.
Muzzle with tentacles ; eye 3.33 times in interorbital space ; head 31-3} times
in length (without caudal). Head wide. Black below, white-dotted.
C. ALGA.

II. Muzzle with a broad naked marginal band; no tentacles; D. I. 7.

Eye three times in interorbital width; head broad, short, 3.75 times in
length; 1. 1. 23. Brown, with indistinct pale spots; uniform below.
, C. MALACOPS.
Eye three times in front, head wedge-shaped, roofed in front, 3.5 times in
length ; naked band narrower ; blackish, white-dotted below.
C. TECTIROSTRIS.
[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 287

Eye 2.83 times in front; head short, contracted at the front, four times in
length ; canthus rostralis vertical concave ; brown, with many large oval
pale spots above only. C. VARIOLUS.

III. Unossified margin of muzzle exceedingly narrow, no tentacles, D. I. 7.

Head short, broad, 4.25 times in length; eye 2.66 in front. Black, below
brown; small. C. SERICEUS.

The smallest of these species, it will be observed, has the most
complete dermo-ossification, and the largest the least. The next
largest species, C. tectirostris, is next most fully ossified, while
the C. malacops, with but little ossification, is after C. sericeus,
and C. variolus the smallest. So there is no relation between the
ossification and the size.

It may be observed that these species all agree in many points
not above mentioned, viz.: Anal radii V.; V. I. 5; P. I. 6; and in
having the inferior lobe of the caudal longer than the superior.
Thorax and belly naked; lateral lines 23-4.

CHEATOSTOMUS ALGA, Cope, sp. nov.

Width of head 3.33 times in length without caudal. Preoper-
cular spines thirteen, of which two posterior are longer, and ex-
tend a little beyond the line of the orbit. Muzzle with numerous
tentacles on the margin and sides, and a V-shaped series above of
larger size, the largest in front at the apex of the V. Dorsal
spine a little longer than base of fin, one-half length; pectoral
spine extending to basal third or two-fifths of ventral spine.
Scuta with ten serrate subequal ridges, each terminating in a spine.
The ossification of the derm forms only a narrow band in front
of nares and orbit.

Total length .165 m. I associate with this species a second
specimen, which agrees in every respect except in wanting tenta-
cles. This is probably, as Gunther states of C. cirrhosus, the
female.

This species is apparently near the latter species, but has a
shorter body.

CHETOSTOMUS MALACOPS, Cope, sp. nov.

The lores are naked to near the nares, but the ossification ex-
tends in an angle to the middle of the muzzle. Width of head

1872.]

288 PROCEEDINGS OF THE ACADEMY OF

3.4 in total without caudal. Ten principal bristles, the longest
not extending to hinder margin of orbit. Dorsal spine longer, 1.5
times in length anterior to it; pectoral reaching beyond base of
ventrals. Ten plates from anal to caudal, five between dorsals.
Color brown, with many closely placed yellow spots. Length
097 m. With the last; two specimens.

CHETOSTOMUS VARIOLUS, Cope, sp. nov.

This species has a much narrower unossified labial margin than
the last, the muzzle being entirely covered above to near the lip.
Thirteen principal opercular spines which do not extend beyond
the line of the orbit; three of them longer and subequal. Loreal
region vertical. Scuta between dorsals 6, between anal and caudal
10. Dorsal spine 1.5 times length from its base to muzzle. Pec-
toral spine a little beyond base of ventral. Ridges of scuta re-
presented by rows of bristles, which give them a hoary appearance.
No keels.

Length .068m. Color bright brown, with numerous large round
yellow spots; belly unspotted. With the last.

CHETOSTOMUS TECTIROSTRIS, Cope, sp. nov.

Naked labial band as wide as space between nares and orbit.
Only eleven preopercular spines, of which two posterior are sub-
equal, longer, and reaching a little beyond line of orbit. Loreal
region oblique, nearly plane. Dorsal spine 1.66 times in length
in advance of it. Pectoral spines to a little beyond ventral.
Scuta between dorsals 5, behind anal 10. The scuta are serrate
ridged as in C. alga. The muzzle is ridged on the median line,
and the sides slope gradually on each side; no other ridges on
the head.

Black, with minute yellow dots above and below. Length .13
m., greatest width of head .031. Two specimens.

CHETOSTOMUS SERICEUS, Cope, sp. nov.

This species has a more elongate body than the others here de-
scribed, the length containing that of the head 4.25 times, and
the width 3.5 times. The head is thus wide and flat, and the
naked portion is reduced to a very narrow band along the margin
of the muzzle. Latter convex in section, loreal region concave.
Kleven spines, the posterior not quite reaching line of posterior

[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 289

rim of orbit. Dorsal spine 1.5 times in length in front of its
base; pectoral scarcely beyond base of ventral. The ridges of
other species are represented by rows of bristles. No ridges on
the head. Color black, unspotted, or in a smaller specimen with
faint pale spots above. Length .067 m. Two specimens with the
preceding.

This species and the C. malacops might have been regarded as
the young of C. tectirostris and C. alga, respectively, were it not
that the larger individuals possess the characters of immaturity
exhibited by other animals, viz., larger head, and less ossification
of the derm of the muzzle.

LORICARIA ACUTA, Cuv. Val.

XV. 472; Gthr., Catal. B. M. v. 258.
From the Ambyiacu.

PARIOLIUS, Cope, gen. nov.

Allied to Trichomycterus. Ventral fins present, anterior to the
short dorsal. Anal fin short; vent situated beneath the dorsal
fin; no adipose fin. No nasal barbel, one maxillary and two
lateral mentals. No armature on any of the opercular bones.
Teeth in brush-like series.

This genus is allied to Trichomycterus in the extensive bran-
chial fissures and other characters, but differs in the absence of
armature of the head, and number and position of tentacles.

PARIOLIUS ARMILLATUS, Cope, sp. nov.

Head flat rounded, eyes small, superior, covered by the skin.
Head 4.5 times in length to basis of caudal fin. Depth at D. I.
one-half length to basis pectoral fin; width of head two-thirds
the same distance. Interorbital width 3.66 times in length of
head. Maxillary and external mental barbels extending beyond
basis of pectoral; inner mental barbel on half the same. Radii
D. 7; P.8; V.6; A. 11; caudal acuminate. Skin entirely smooth.

Color dark-brown, nearly black on the top of the head; under
surfaces from anus brownish-yellow, brown punctulate. <A broad
yellow collar extends from the under surface on each side across
the bases of the pectoral fins and the vertex. A vertical dark
spot on base of caudal; fins brown-spotted.

1872.]

290 PROCEEDINGS OF THE ACADEMY OF

M.

Total length . : : : c : : < . 0.041

Length to opercular edge ' ; ; é : ~. 20078
es pectoral fin . ; ; ‘ : 6 . 008
ub dorsal . : : : : : . . .0158
a anal : : ; 5 5 : : . 0245
is caudal . F ; c : - : . 033

From the Ambyiacu, Jno. Hauxwell.

PARIODON MICROPS, Kner,
Sitzungsb. Wien. Acad., 1855, p. 161. Giinther, Catal. B. Mus. v. 275.

A fine specimen of this fish was obtained by Robert Perkins.
It is nearly allied to Stegophilus Rhdt., and belongs to the Stego-
philina of Gunther. The latter author, however, places it in his
Trichomycterina, a step calculated to mislead the student, as it
contradicts its natural characters. Giinther does not appear to
have seen the fish, and perhaps Kner omits mention of the cha-
racters necessary to decide the question. It possesses the very
posterior vent, and the gill covers united with the throat found
by Gunther to define the Stegophilina.

SYMBRANCHIDA:

SYMBRANCHUS MARMORATUS, BI.

The fishes of the Ambyiacu, so far as made known by the pre-
ceding investigation, are referable to eight families, fifty genera,
and seventy-four species. These are distributed as follows :—

Gen. Species,

CHROMIDIDA, T 15
CLUPEIDA, 1 1
OSTEOGLOSSID A, 1 1
STERNOPYGIDA, 2 3
ERYTHRINIDA, 2 2
CHARACINIDA, 21 29
SILURIDA, 1S) 24
SYMBRANCHIDA, 1 1

Forty-seven of the above species and nine of the genera are
new to science, and are referable to the following families :—
[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 291

Gen. Species.
CHROMIDIDA, 0 9
ERYTHINIDA, 0 1
CHARACINIDA, 3 16
SILURIDA, 6 20

The general character of this list is that of any other part of
the Amazon basin, presenting peculiarities in peculiar species and
in genera not found in the lower Amazon. Such genera among
Characinde are Triportheus, Megalobrycon, Aphyocharax, Iquano-
dectes, and Stethaprion; among Siluride, Dianema, Brochis, Za-
thorax, Physopyxis, Otocinclus, and Pariolius. A genus (Cha-
racidium) previously only known by one small species from a
Brazilian coast stream, has its range greatly extended by the
discovery of a species in the Ambyiacu.

The species contained in the Perkins collection are as follows :—

CHROMIDIDZE.

PTEROPHYLLUM SCALARE, C. V.

SYMPHYSODON Discus, Heck.

CICHLA OCELLARIS, Bl. Schn.

GEOPHAGUS PROXIMUS, Cast. Radii D. XVII-XVIII-11; A. ITI-
8. Scales 6-34-12, upper and lower halves caudal fin scaly to
near end.

HYGROGONUS OCELLATUS, Agass.

SCIAENIDE.
One species.
PLEURONECTIDZE,
One species.
OSTEOGLOSSIDE.

OSTEOGLOSSUM BICIRRHOSUM, Vand.

CHARACINIDE.

CURIMATUS OYPRINOIDES, L.
HEMIODUS MICROLEPIS, Kner.
TETRAGONOPTERUS CHALCEUS, Artedi.
MYLETES ALBISCOPUS, Cope.
MYLETES BIDENS, Spix.

MYLETES, sp. nov.

1872. ]

292 PROCEEDINGS OF THE ACADEMY OF

SERRASALMO @&SoPuS, Cope.
SERRASALMO HUMERALIS, Kner.
SERRASALMO NATTERERI, Kner.
HYDROLYCUS SCOMBEROIDES, Spix.
R@BOIDES RUBRIVERTEX, Cope.

SILURIDE.

CETOPSIS C@HCUTIENS, Licht.

PARIODON Microps, Kner.

PIRAMUTANA, Sp. Nov.

CALLOPHYSUS LATERALIS, Gill.
PHRACTOCEPHALUS HEMILIOPTERUS, Bl. Schn.
RHINODORAS NIGER, Valenc.

DoRAS BRACHIATUS, Cope.

PLECOSTOMUS SCOPULARTUS, Cope.
PLECOSTOMUS BISERIATUS, Cope.

LIposarcuS VARIUS, Cope.

[February 13,

NATURAL SCIENCES OF PHILADELPHIA. 293

EXPLANATION OF THE PLATES.

Puate III.

1. Doras pectinifrons Cope.

PLATE IV.

Fig. 1. Zathorax monitor Cope; b from below ; ¢ from front.
. Otocinelus vestitus Cope; b from above; ¢ head, side view.

vo

PLATE V.
Fig. 1. Physopyzis lyra Cope; b from below ; ¢ from front.
** 2. Chetostomus malacops Cope; 6 from below.

Prats VI.

Fig. 1. Corydoras semiscutatus Cope; b from below.
‘* 2. Corydoras trilineatus Cope; b from above ; ¢ from below.

Prate VII.

Fig. 1. Dianema longibarbis Cope; a from above; 6 from below.
‘* 2. Brochis coeruleus Cope; a from above; 0 from below.

Prats VIII.

Fig. 1. Iguanodectes tenuis Cope (adipose fin omitted by artist) ; 1a denti-
tion.
‘2. Characidium etheostoma Cope; dentition.
3. Triportheus albus Cope; dentition.

PuatE IX.
Fig. 1. Anacyrius sanguineus Cope.
‘¢ 2. Serrasalmo tridopsis Cope.
‘* 5. Brochis coeruleus Cope.
PLATE X.
Fig. 1. Crenicichla anthurus Cope.
‘ 2. Megalobrycon erythropterum Cope.
PuaTE XI.
Fig. 1. Geophagus badiipinnis Cope.

i,
2. Uarus centrarchoides Cope.
© 3. Acara syspilus Cope.
4. Acara flavilabris Cope.
1872.] PART I1I1.—20

294 PROCEEDINGS OF THE ACADEMY OF

PuaTE XII.
Fig. 1. Myletes albiscopus Cope.
2. Myletes oculus Cope.
. Myletes herniarius Cope.

C2 d

Puate XIII.

Fig. 1. Megalobrycon melanopterum Cope.
‘6 2. Xiphostoma tado Cope.
© 3. Characidium etheostoma Cope.
PLATE XIV.
Fig. 1. Triportheus flavus Cope.
‘* 2. Triportheus albus Cope.
‘¢ 3. Chaleinus culter Cope.
‘© 4, Callichthys melampterus Cope.
‘* 5. The same; head from above.
PuATE XY.
Fig. 1. Doras grypus Cope.
COmtCh Do. from below.
‘¢ 2. Chetostomus tectirostris Cope.
‘¢ 3. Chetostomus alga Cope, from above.

PLATE XVI.

Fig. 1. Plecostomus scopularius Cope; one-fourth natural size.
‘* 2. Same from below.

PuatTEe XVII.

. Nothopsis rugosus Cope.

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Trigonocephalus atrox Cope, var. from Central America.

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[February 13,

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