FISHES CYPRINIDAE — POGONICHTHYS INAEQUILOBUS. 245 



POGONICHTIIYS, Girard. 



Gek. Char. The body is fusiform and eloiiirated, compressed, covered with large and uniform scales, and provided with a 



conspicuous lateral line defloxed 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 posilion, 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 eje 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 ofl" 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. 



Sitt. —Pogonichthys, Grd. in Proc. Acad. Nat. Sc, Philad. VII, 1854, 136 ; &, VIII, 1856, 187. 



This genus is allied to GoMo, 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 LVI, 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. — Pogonichtkys inaequilobits, 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 be 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 ; C 8, 1, 9, 8, 1, 7 ; V 1, 9 ; P 17. 



The scales are large ; fifty-six of these may be 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 sub-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. 



References to the /(/?<res.— Plate LVI, fig. 1, represents Fogonichtht/s inaequilohus, size of 

 life. Fig, 2 is a scale irom the dorsal region. Fig. 3, a scale from the lateral line. Fig. 4, a 

 scale from the abdominal region. 



