FI-HES. 23 



10. LAVINIA EXILICAUDA, B. & G. 

 Gen. Kep. 241.— Plate LIV, Figs. 1—4. 



Spec Char. — Body very compressed, quite deep upon its middle i 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, ihe scales being minutely dotted upon their margin. Beneath yellowish. 



207. Sacramento river, California. Dr. A. L. Heermann. 



11. ARGYREUS DULCIS, Grd. 

 Gen. Kep. 243.— Plate LIV, 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 enterirg six times in the length of the side of the head. Anterior 

 margia 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 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 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 being 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. Eep. 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 

 stoutieh 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. Eep. 256.— Plate LVI, 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. Shumard. 



