52 FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V. 



Head 3^3 ; depth 3^; D. 8; A. 8; scales 6-35-20. Body oblong, 

 compressed; dorsal and ventral outlines similar; snout short, less 

 than diameter of eye; mouth oblique, the maxillary not reaching 

 vertical from front of eye; lower jaw the longer; pectorals not reach- 

 ing ventrals; the latter to anal. 



Color brown, silvery below; a broad brown lateral band bordered 

 above by a narrow silvery line. (Garman.) 



A small fish, known only from the above account. 



Subfamily Leuciscinse. 

 2O. Ptychoeheilus Agassiz. 



Ptychocheilus Agassiz, Amer. Journ. Sci. Arts, 1855, 229. (Type, 

 Ptychocheilus gracilis Agassiz.) 



Body elongate, little elevated, the caudal peduncle not contracted; 

 head long and slender, pike-like; mouth nearly horizontal, widely 

 cleft, the maxillary extending below the eye; the margin of the upper 

 lip rather lower than the inferior margin of the eye; lower jaw in- 

 cluded ; no barbels ; lips thick ; scales small ; mostly longer than deep : 

 lateral line decurved; gill rakers very short; dorsal fin some- 

 what behind ventrals; anal base short; caudal fin strong; intestinal 

 canal short; teeth 2, 5-4, 2; the straight limb of the pharyngeal 

 bone extremely long and slender, its teeth wide apart; teeth sub- 

 conical, scarcely compressed and but slightly curved at the tip; no 

 grinding surface. Minnows of very large size. 



44. Ptychocheilus lucius Girard. WHITE SALMON OF THE COL- 

 ORADO RIVER. 



Ptychocheilus lucius Girard, Proc. Acad. Nat. Sci. Phila., 1856, 

 209; Rio Colorado: Jordan & Evermann, Bull. 47, U. S. Nat. 

 Mus., 1896, 225: Bean, Bull. Amer. Mus. Nat. Hist., 1898, 

 165; Northern Sonora: Gilbert & Scofield, Proc. U. S. Nat. 

 Mus., 1898, 492; Colorado River at Yuma and Horseshoe 

 Bend, near its mouth. 



Sonora and the Colorado River Basin, north to the Uncompagre 

 River at Delta, Colorado. 



Head 3X5 depth 5X1 D. 9; A. 9; scales 83 to 87. Body slender, 

 elongate, with long, slender, depressed head; eye small, 2^ in the 

 snout, 7 in head; mouth large; maxillary 2f in head, its tip reaching 

 past vertical from anterior margin of eye ; teeth 2 , 4-5 , 2 ; lateral 

 line strongly decurved; fins moderate. 



Color plain, darker above; the young always with a caudal spot 

 and a faint pale lateral line below a darker one. .Length about 4 feet. 



