228 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
broad as deep, and nearl^^ terete, its length (from end of anal to middle 
of base of caudal) 1^ times the length of the head, its least depth about 
one-seventh of its length, its extremity dilated and compressed. Head 
short, broad, the snout dej^ressed and broadly rounded; the anterior 
part of the head from behind the eyes broad and depressed; the pos- 
terior part high, so that the i)rotile forms a concave arc. Mouth rather 
large, nearly horizontal, the upper lip on the level of the lower i)art of 
orbit, the maxillary extending to the front of the orbit, the lower jaw 
on all sides included. Skiu of the lower jaw hard. Eye small, anterior, 
placed low, 5 in head. Isthmus narrow. Gill-rakers rather weak. 
Fins all long and falcate. Pectorals reaching ventrals. Caudal fin 
deeply forked, its lobes long and iminted, the ui)per somewhat the 
longer; the rudimental basal rays strong, about 12 in number on each 
sides. Scales scarcely imbricated at all, on the caudal peduncle hardly 
touching each other, on the sides of the body much longer than deep ; 
their texture thin and membranaceous; scales on back and belly much 
smaller than those on the sides. Coloration bluish above, pale below. 
Head 5; depths. D. 9; A. 10; scales 23-98-10 ; teeth 2, 4-5, 2. L. 12 
inches. Colorado and Gila Fivers. 
(Baird & Girard, Proc. Acad. Nat. Sci. Pliila. 1853, 369; Girard, U. S. Pac. R. R. 
Surv. X, 286: Leiiciscus clegaiis Giiiither, vii, 241.) 
360. Cl. rohiista Baird & Girard. 
Body elongate, the back elevated and the head depressed as in G. 
elegans, but the caudal petluucle notably stouter, its least depth about 
one-third its length, of in the length of the head. Mouth large, the 
upi)er lip on the level of the lower part of the orbit, the maxillary reach- 
ing past the front of the orbit. Fins rather lower than in G. elegans, 
the pectorals in the male reaching the ventrals, but falling short in the 
female. Eye small, low, anterior, 5-8 in bead. Lateral line much de- 
curved. Coloration plain. Head 4; depth 5. I). 9; A. 9; scales 
17-90-10; teeth 2, 5-4, 2. L. 12 inches. Eio Colorado and Eio Gila. 
(Biiird & Girard, Proc. Acad. Nat. Sci. Pliila. 1853, 368, and U. S. Pac. R. R. Surv. 
X, 285: Leitcisciis robustiis Giintlier, vii, 241.) 
361. Cjt. Baird & Girard. 
General form of the preceding, with similar head and caudal pedun- 
cle, but with rather larger and more closely imbricated scales. Upper 
lip below level of eye, maxillary reaching front of orb^t. Caudal tin less 
deeidy forked, and pectorals not reaching nearly to ventrals. Colora- 
