FliHES. 
23 
10. LAYINIA EXILICAUDA, B. & G. 
Gen. Bep. 241.— Plate LIY, Figs. 1—4. 
Spec Char. —Body very compressed, quite deep upon its middle; peduncle of tail rather slender. Head small; eye 
moderate; posterior extremity of maxillary not reaching the anterior rim of the orbit. Isthmus small. Insertion of ventral 
fins situated in advance of the anterior margin of the dorsal. Pectorals rather small Caudal deeply furcated. Reddish 
brown above, silvery grey on the sides, the scales being minutely dotted upon their margin. Beneath yellowish. 
201. Sacramento river, California. Dr. A. L. Heermann. 
11. ARGYREUS DULCIS, Grd. 
Gen. Rep. 243.— Plate LIY, Figs. 5—8. 
Spec. Char. —Head well developed, constituting the fourth of the length, caudal fin excluded. Mouth large, and barbel 
conspicuous; lips fleshy. Eye small, sub-circular, its diameter entering six times in the length of the side of the head. Anterior 
margin of dorsal fin equidistant between the extremity of the snout and the tip of the middle rays of the caudal. Insertion of 
ventral fins somewhat nearer the angle of the mouth than the base of the caudal. Color greyish yellow above; yellowish white 
beneath ; sides sprinkled with an indistinct silvery band. 
53. Cottonwood creek, Utah. Mr. Kreuzfeld. 
12. POGONICHTHYS INAEQUILOBUS, B. & G. 
Gen. Rep. 245.— 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 vertical 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 beiDg nearly equidistant 
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. 
182. Sacramento river, California. Dr. A. L. Heermann. 
13. NOCOMIS NEBRASCENSIS, Grd. 
Gen. Rep. 254. 
Spec. Char. —Head contained four times and a half in the total length. Posterior extremity of maxillary even with a vertical 
line drawn behind the nostrils. Eye sub-circular; its diameter entering five times in the length of the side of the head. Body 
stoutish and compressed, covered with large scales. Anterior margin of dorsal fin nearer the insertion of the caudal than the 
extremity of the snout. Dorsal and anal fins deeper than long. Caudal fin constituting the fifth of the length. Tip of ventrals 
overlapping the vent, although not reaching the anal fin. Eeddish brown above, golden yellow beneath. 
48. Sweetwater, tributary of Platte river. J. S. Bowman. 
14. EXOGLOSSUM MIRABILE, Grd. 
Gen. Rep. 256.— Plate LYI, Figs. 5—8. 
Spec. Char. —Head sub-conical, blunt, and constituting the sixth of the total length. Mouth small; posterior extremity of 
maxillar bone even with a vertical line drawn across the nostrils. Eye sub-circular; its diameter entering four times in the 
length of the side of the head. Anterior margin of dorsal much nearer the extremity of the snout than the base of the caudal. 
Insertion of ventrals placed somewhat posteriorly to the anterior margin of the dorsal, their tip nearly reaching the vent. 
Reddish brown above; middle of flank with a silvery band ; beneath light reddish. 
47. Arkansas river, near Fort Smith. Dr. Geo. G. Skumard. 
