230 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



of the back. Mouth small, nearly terminal, the maxillary not reaching 



to the front of the orbit. Eye rather large, interior, not placed low. 



Scales small, especially on the back and belly, the exposed surfaces 



longer than deep. Fins large ; the pectorals reaching ventrals ; the 



caudal deeply forked. Doi*sal fin inserted nearer the top of snout than 



to the base of caudal. Head 4^ ; depth U. D. 9 ; A. 9 ; Lat. 1. 98. Rio 



Gila. (Girard.) 



(Baird & Girard, Proc. Acad. Nat. Sci. Phila. ISfiS, 388; Girard, U. S. Mex. Bound. 

 Surv. Ichth. 62: Leucisciia emorii Giiutlier, vii, 242.) 



365. G. iiacvea Cope. 



Body rather slender ; profile and interorbital region gently convex. 

 Maxillary not reaching line of orbit. Caudal peduncle slender, its least 

 depth 4 in head. Eye 5 in head. Pectorals not reaching ventrals. 

 Dorsal behind ventrals. Silvery white; back narrowly dark-shaded; 

 pectoral fins pink. Head 4; depth 4|. D. 9; A. 10; scales 21-'?-13; 

 teeth 2, 5-4, 2. Green River (Rio Colorado). (Cope.) 



(Cope, Hayden'a Geol Snrv. Wyom. 1870, 441, 1872. 

 aa. Belly scaleless. 



366. G. soiniiiuda Cope & Yarrow. 



Body moderately deep, with slender and tapering caudal peduncle, 

 the least depth of which is about one-third its length. Back little ele- 

 vated, not arched in front of dorsal. Head small, transversely convex, 

 its profile continuous with that of the back and not concave. Mouth 

 rather small, oblique, terminal, the upper lij) opposite the middle of the 

 orbit, the maxillary not reaching the line of the orbit. Eye large, rather 

 anterior, but not very low, its length 4 in head. Fins moderate. Dor- 

 sal slightly behind ventrals. Brownish above, lower fins pink. Head 

 5; depth o^. D. 10; A. 10: scales 21-98-12; teeth 2, 5-4, 2. L. G 

 inches. Rio Virgen, in Utah. {Cope.) This species forms a transition 

 to SquaUus and other normally formed Cyprinidce. 



(Cope & Yarrow, Zool. Wheeler's Expl. W. 100th Mer. v, 666, 1876.) 



lOa.— SQUACIUS Bonaparte. 

 ]}ace. 



( re?es<es Bonaparte ; Cheonda, Tigoma, Sibotna, and Clinostomus Girard.) 



(Bonaparte, Fauna Italica, 1837, ^ 6: type Ct/prinus leuciscus L., the European 

 "Dace".) 



Body oblong, compressed or robust, covered with moderate or small 

 scales, which are not closely imbricated. Lateral line complete, de- 

 curved. Mouth large or small, usually terminal, the lips normal, with- 

 out barbel. Teeth mostly 2, 5-4, 2, sometimes 2, 5-5, 2, or 1, 5-4, 2, 



