248 
U. S. P R. R. EXP. 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 figures .—Plate LV, fig. 1, represents Pogonichthys communis, size of life s 
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. 
Catal. 
No. 
Cor’g No. 
of teeth. 
No of 
specs. 
Age. Locality. 
When 
collected 
Whence obtained. 
Nature of 
specimens. 
Collected by— 
181 
2743 
24 
A.&Y. Milk river, upper Mo. 
1853 
Gov 1. I. Stevens. 
Alcoholic .. 
Dr. Geo. Suckley. 
00 
r—( 
2744 
1 
Young* Sweet Water fork of 
1852 
J. S. Bowman.... 
.do. 
J. S. Bowman. 
Platte river. 
185 
12 
1852 
E. J. Denio*... 
186 
10 
A.&Y. Milk river, 125 miles 
1853 
Gov. I. I. Stevens. 
.do. 
Dr. Geo. Suckley..#. 
above Fort Union. 
187 
2745 
] 
1853 
188 
2746 
5 
..do..j Yellowstone riv. 
1853 
Col. A. Vaughan . 
.do. 
Dr. F. V. Hayden. 
189 
2747 
8 
A.&Y. Above Fort Union.. 
1853 
Gov. 1.1. Stevens. 
.do. 
Dr. Geo. Suckley. 
GOBIO, Cuv. 
Gen. Char.— Head sub-conical, with the snout rather thick and obtuse, overlapping the lower jaw, thus giving the mouth a 
somewhat inferior position. The latter, however, is directed forwards; it is large, and provided with a well developed barbel upon 
the posterior extremity of the maxillar bone. The eye is of moderate development. The isthmus is wide. The body is elongated, 
sub-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, sub-cylindrical upon their base, compressed above, of the raptatorial kind of the hooked type, without grinding 
surface, and disposed upon a double series of one, two, or three, and three, four, or five, as follows : 3 | 5—5 | 2, or 2 | 4— 
4 | 1, &c., &c. 
Syn.— Gobio, Cuv. Regn. Anim. II, 1817, 193 ; 2d ed. II, 1829; &, ed. Illustr. Poiss. 218.—Cuv. & Val. Hist. nat. des 
Poiss. XVI, 1842, 298 —Heck, in Russeg. Reisen, I, h, 1842, 1028.— De Kay, 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 Fishes, Plate XXIX, Figs. 5—9. 
Spec. Char.— Head constituting the fifth of the entire length in which the 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 ; 
the anterior margin of the dorsal fin 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. 
Syn. — Gobio geliclus, Grd. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 188 
