248 



U. S. P R. R. KXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



The dorsal region is reddish grey or greyish red, according to circumstances ; the rest of the 



body is whitish yellow or yellowish golden, the fins being unicolor. 



We have examined numerous specimens of this species, as exhibited by the following list : 

 Beferences to the fi(jures. — Plate LV, fig. 1, represents Pogonichthys communis, size of life 



Fig. 2 is an outline of the head seen from below showing the shape of the mouth. Fig. 3, an 



outline of the fish seen from above. Fig. 4, a dorsal scale. Fig. 5, a scale from the lateral 



line. Fig, 6, a scale from the abdominal region. 



List of specimens. 



GOBIO, Cuv. 



Gen. Char. — Head sub-conical, v>'ith the snout rather thick and obtuse, overlapping the lower jaw, thus giving the mouth a 

 somewhat inferior position. The hitter, however, is directed forwards; it is large, and provided with a well developed barbel upon 

 the posterior extremity of the ma.\illar bone. The eye is of moderate development. The isthmus is wide. The body is elongated, 

 8ub-cvlindrical. The dorsal and anal both are rather narrow fins. The insertion of the ventrals takes place under the anterior 

 margin of the dorsal, or a little behind it. The caudal is furcated. The scales are large, and the lateral line nearly median. 

 The pharyngeals are gracefully curved, the upper and lower branches tapering, the convexity very slightly expanded. The 

 teeth are slender, suo-cylindrical upon their base, compressed above, of the raptatorial kind of the hooked type, without grinding 

 surface, and disposed npon a double series of one, two, or three, and three, four, or five, as follows : 3 | 5 — 5 | 2, or 2 | 4 — 

 4 I l,&c., &.C. 



Sin.— Golio, Cuv. R£gn. Anim. II, 1817, 193; 2d ed. II, 1829; &, cd. Illustr. Poiss. 218.— Cov. & Val. Hist. nat. dos 

 Poiss. XVI, 1842, 298— Heck, in Russeg. Reisen, I, ii, 1842, 103S.— De Kat, New Y. Faun. IV. 1842, 

 394.— Storer, Synops. 1846, 155.— Grd. in Proc. Acad. Nat Sc. Philad. VIII, 1856, 188. 



This genus may be distinguished from Leucosomus by a more protruding snout, much more 

 developed maxillar barbel, narrower dorsal and anal fins, and finally by its pharyngeal teeth, 

 which are more strongly hooked. 



1. GOBIO GELIDUS, Grd. 

 U. S. & Mex. Boundary Fishe.';, Plate XXIX, Fios. 5—9. 



Spec. Char.— Head constituting the fifth of the entire length in which tlio caudal fin enters but four times and a half Eye 

 small, sub-elliptical, its horizontal diameter entering four times in the length of the side of the head. Body slender and tapering; 

 'he anterior margin of the dorsal lin is nearer the extremity of the snout than the insertion of the caudal. Tip of pectorals 

 reaching to the base of the ventrals ; tip of ventrals overlapping the vent, not extending quite to the anterior margin of the 

 anal. Yellowish brown, with a silvery, superiorly dusky, streak along the middle of the flanks. 

 S\N.— Gobio gelidus, Grd. in Proc. Acad. Nat. Sc. I'hilad. VIII, 1856, 188 



