PLECTOSPONDYLI CYPRINIDAE GILA ROBTJSTA. 



663 



GILA NIGRA, Cope, sp. nov. 

 PLATE XXX, FIGS. 3, 3a. 



This species, which is represented by a number of specimens in the 

 collection of the survey, resembles those last enumerated, and differs from 

 the G. pandora in the considerably more numerous scales ; from the G. egre- 

 gia it differs in the relatively larger head, which enters the length minus 

 the caudal fin only three and one-half times, instead of four times. The 



21 20 20 



dental series is found to be in several specimens 4.2-2.5. Scales, 57, re, se, in 



12 11 11 



three specimens. General shape fusiform ; profile gradually descending, 

 then decurved to the upper lip, which overhangs the lower by a little ; 

 mouth slightly descending. Teeth, 4.2-2.5 ; isthmus rather wide. Eye 

 not large ; in adults six times in length of head, 1.75 times in muzzle, and 

 twice in interorbital width. The fins are all rather small, including the cau- 

 dal ; the pectorals reach 0.6 the distance to the ventrals, and the latter 0.6 the 

 distance to the anal. Radii : D. I. 8 ; A. I. 8 ; V. 9. Least depth of caudal 

 peduncle 2.6 times into greatest depth (in front of dorsal fin), which enters 

 the length without the caudal fin four times. Total length, O m .235 (7 

 inches) ; length to basis of first dorsal ray, O m .113 ; length to basis of caudal 

 fin, O m .200. 



General color black. Lower surfaces olive. 



GILA ROBUSTA, Bel. & Gir. 



Gila robitsta, Bu. & GIB., Proc. Acad. Nat. Sci. Phila., vi, 1853, 369. lid., Sitgreave's 

 Exp. Zimi & Col. Riv., 1853, Fishes, 148, pi. 1, f. 1. lid., P. R. K. Rep., x, 



1857, Fishes, 285. 



A comparison of two good specimens with Baird and Girard's descrip- 

 tion reveals some trifling differences with regard to number of radii. Speci- 

 men No. 504, from Zufli River, New Mexico, has the following formula: 



