664 



ZOOLOGY FISHES. 



Br. 3 on each side; D. 1-10; A. 1-11; C. 8-1-8-8-1-8; V. 1-8; P. 13; 

 teeth 4.1-5.2. In this specimen, the head enters the total length including 

 caudal fin 4.50 times ; eye entering length of side of head 7 times ; base 

 of anal fin 11.50 in total length. 



Specimen No. 504 A, from same locality, has: Br. 3-3; D. 1-11; A. 

 1-10 ; C. 8-1-8-8-1-7 ; V. 1-8 ; P. 13 ; teeth 4.2-4.2. Head enters total length 

 4,50 times; eye in length of side of head 7.75; base of anal fin 10.50 of 

 total length. All the individuals of this species which have been examined 

 possess on the end of the snout a little behind its anterior margin and on 

 the median line of the head, a peculiar knob or tubercle, which is more 

 plainly visible in alcoholic than fresh specimens. Gila gracilis possesses it 

 in a much less marked degree. 



GILA ELEGANS, Bel. & Gir. 



Gila elegans, BD. & GIR., Proc. Acad. Nat. Sci. Phila., vi, 1853, 309. lid., Sitgreave's 

 Exp. Zirai & Col. Eiv., 1853, 150, pi. ii. GIR., Proc. Acad. Nat, Sci- 

 Pbila., viii, 1856, 205. Id., U S. & Mex. Bouud. Snrv., pt, ii, 1859, Ichtby. 

 ology, 01. COPE, U. S. Geol. Surv. Terr., 1870, 441. 



This species, resembling the preceding, but more elongated in form, 

 and having larger scales, has been but sparingly observed by the members 

 of this expedition ; the only specimen having been brought from South- 

 western Arizona by F. Bischoff of the expedition of 1871. This is in such 

 bad condition that the distinctive characters can hardly be made out. 



