FISHES-CYPRINIDAE-POGONICHTHYS INAEQUILOBUS. 
245 
POGONICHTHYS, Girard. 
Gen. Char. —The body is fusiform and elongated, compressed, covered with large and uniform scales, and provided with a 
conspicuous lateral line deflexed upon the middle of the abdomen. The dorsal fin is higher than long ; the ventrals are inserted 
in advance of the anterior margin of the dorsal or behind it. The caudal is furcated. The head is of moderate size or else 
small, either rounded or flattened upon its upper surface. The snout being more or less protruding beyond the lower jaw, the 
mouth assumes a somewhat inferior position, although opening horizontally forwards. The mouth itself is of medium size, 
provided at its angle with a barbel inserted upon the anterior edge of the posterior extremity of the maxillary. The eye is 
of moderate development. The isthmus is quite narrow. The pharyngeal bones are proportionally stout, the inferior limb 
being, however, slender, slightly arched and expanded upon its symphysis. About the height of the third tooth the convexity 
suddenly expands, tapering off towards the extremity of the upper branch, which is slightly bent inwardly downwards. The 
teeth are well developed, very much compressed upwards and hooked. They are of the prehensile kind, of the hooked type, 
with a grinding surface, somewhat inclined backwards, and disposed upon a double row of two and four : 2 | 4—4 | 2. 
Syn. — Pogonichthys, Grd. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 136 ; &, VIII, 1856, 187. 
This genus is allied to Gobio, from which it differs by a narrow isthmus, and especially by 
its teeth, which are of the prehensile kind, with a grinding surface, whilst those of Gobio are 
of the raptatorial kind, without grinding surface. 
1. POGONICHTHYS INAEQUILOBUS, B. & G. 
Plate LYI, Figs. 1 — 4. 
Spec. Char. —Head forming a little less than the fifth of the total length ; snout rounded, sub-conical, thickish ; gape of 
mouth nearly horizontal ; lower jaw shorter than the upper. Posterior extremity of maxillar bone scarcely even with a verticaj 
line drawn in front of the orbit. Anterior margin of dorsal fin somewhat nearer the extremity of the snout than the insertion 
of the caudal. Insertion of ventrals placed posteriorly to the anterior margin of the dorsal ; their origin being nearly equi¬ 
distant between the extremity of the snout and the base of the caudal. Lobes of the caudal fin unequally developed ; upper 
one the longest. Greyish brown above ; yellowish beneath. 
Syn. — Pogonichthys inaequilobus, B. & G. in Proc. Acad. Nat. Sc. Philad. VII, 1854, 136.— Grd. in Proc. Acad. Nat. Sc. 
Philad. VIII, 1856, 188. 
The general form is very regular, sub-fusiform and compressed. The total length of the 
specimen described is about ten inches, of which the head forms a little less than the fifth part. 
The eye is sub-circular; its diameter being comprised about five times in the length of the side of the 
head. The mouth is of medium size ; its cleft does not quite extend to a vertical line drawn in 
advance of the orbit. A barbel, about an eighth of an inch, may he observed at the angle of 
the mouth. The origin of the dorsal fin is equidistant between the extremity of the snout and 
the first rudimentary rays of the caudal. The caudal is long and deeply furcated ; its upper 
lobe projecting beyond the lower, although the structure of that fin is perfectly homorcercal. 
The anal is inserted at some distance behind the dorsal. The insertion of the ventrals is 
situated somewhat behind the origin of the dorsal, and consequently a little nearer the 
rudimentary rays of the caudal than to extremity of snout. The pectorals are moderate sized. 
D 2, 9 ; A 2, 9 ; 0 8, 1, 9, 8, 1, 7 ; Y 1, 9; P 17. 
The scales are large; fifty-six of these may he counted in the lateral line, which, upon the 
abdomen, approximates more the ventral than the dorsal outline. They are moderate sized, 
somewhat longer than deep, anteriorly suh-truncated, posteriorly rounded, with radiating 
furrows upon their posterior section only. 
The upper regions of the head and body are greyish brown ; the sides and abdomen yellowish. 
The fins partake of the color of the region of the body to which they belong. 
Beferences to the figures. —Plate LYI, fig. 1, represents Pogonichthys inaequilobus , size of 
life. Fig. 2 is a scale from the dorsal region. Fig. 3, a scale from the lateral line. Fig. 4, a 
scale from the abdominal region. 
