FAMILY V. CYPRINID.E. 53 



This is the largest member of the American Cyprinida, reaching 

 a weight of 80 pounds. It has been taken in northern (probably 

 in the Rio Sonora or Rio Yaqui) Sonora; otherwise known only from 

 the Colorado Basin. 



21. Grila Baird & Girard. 



Gila Baird & Girard, Proc. Acad. Nat. Sci. Phila., 1853, 368. 

 (Type, Gila robusta Baird & Girard.) 



Body elongate, little compressed; the back arched, especially in 

 the adult; the caudal peduncle extremely long, slender, contracted, 

 much narrower than the base of the caudal fin which is widely forked, 

 with its basal fulcra very much developed; head broad, more or less 

 depressed, its profile concave; mouth large, horizontal and over- 

 lapped by the broad snout; dorsal fin behind the middle of the body, 

 slightly behind ventrals; anal base short; intestinal canal short; 

 peritoneum dusky; scales very small, longer than deep, especially 

 posteriorly; no barbels; teeth 2, 5-4, 2, closely set, compressed and 

 hooked, without grinding surface; vertebrae 42 to 46. Minnows of 

 large size, known only from the Colorado, Gila, and Yaqui rivers. 

 These fishes are easily distinguished from others of the family by 

 the long, slender caudal peduncle. 



KEY TO THE SPECIES OF GILA. 

 a. Head short, 5 in the length; anal rays 10; PAGE 



caudal peduncle long and slender, as broad as 



deep; tips of pectorals reaching % distance to 



base of ventrals elegans 53 



aa. Head longer, 3^ in the length; anal rays 8; 



caudal peduncle more robust ; tips of pectorals 



reaching to base of ventrals minaca 54 



45. Gila elegans Baird & Girard. BONY-TAIL; GILA TROUT. 



Gila elegans Baird & Girard, Proc. Acad. Nat. Sci. Phila., 1853, 

 369; Zuni, Colorado, and Gila rivers: Jordan & Evermann, 

 Bull. 47, U. S. Nat. Mus., 1896, 226: Gilbert & Scofield, Proc. 

 U. S. Nat. Mus., 1898, 492; Colorado and Gila rivers, at 

 Yuma and Horseshoe Bend. 

 Channels of the Colorado and Gila rivers. 



Head 5; depth 5; D. 9; A. 10; scales 23-85-10. Body elongate, 

 somewhat compressed, the region before the dorsal elevated, forming 

 a sort of hump; head short, broad; the snout depressed and broadly 

 rounded; the anterior part of the head from behind the eyes broad 

 and depressed, the posterior part high, so that the profile forms a 



