228 CONTRIBUTIONS TO NORTII AMERICAN ICHTHYOLOGY IV. 



broad as deep, and nearly terete, its length (from end of anal to middle 

 of base of caudal) li 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 depressed and broadly rounded; the anterior 

 part of the head from behind the eyes broad and depressed; the pos- 

 terior part high, so that the profile forms a concave arc. Mouth rather 

 large, nearly horizontal, the upper lip on the level of the lower part of 

 orbit, the maxillary extending to the front of the orbit, the lower jaw 

 on all sides included. Skin 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 tin 

 deeply forked, its lobes long and pointed, the upper 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; depth 5. D. 0; A. 10; scales 23-98-10; teeth 2, 4-5, 2. L. 12 

 inches. Colorado and Gila Rivers. 



(Baird & Girard, Proc. Acad. Nat. Sci. Phila. 1853, 369; Girard, U. S. Par. 11. R. 

 Sui v. x. 286: Leuciiicw tlegans Giiuther, vii, 241.) 



:;OO. G. robusta Baird &, Girard. 



Body elongate, the back elevated and the head depressed as in (r. 

 clrtinitti, but the caudal peduncle notably stouter, its least depth about 

 one-third its length, 3;J in the length of the head. Mouth large, the 

 upper lip o;i the level of the lower part of the orbit, the maxillary reach- 

 ing past the front of the orbit. Fins rather lower than in (f. t'leiiintx. 

 the pectorals in the male reaching the ventrals, but falling short in the 

 female. Kye small, low, anterior, 5-S in head. Lateral line much de- 

 curved. Coloration plain. Head 1: depth 5. D. '>: A. !>; scales 

 17_<M>-1<>: teeth 2, 5-4, 2. L. 12 inches. Kio Colorado and Kin Cila. 



i IJainl A (Jirard. I'm.-. A. -ail. Nat. Sri. I'hila. 18.">::. 368, and 1". S. far. K. K. Snrv. 

 \, .'-.".: l.'in i-riiM rnbimtHi Giinthrr, vii. 241.) 



:;<>!. C.. ;.-] uhailli I'.ainl A (Jiranl. 



(ieneral form of the preceding, with similar head and caudal pedun- 

 cle, ltit with rather larger and more closely imbricated scales. Tpper 

 lip below level of e\e. ma xillary reaching front of orbit . Caudal fin less 

 deeply forked, and pectorals not reaching nearly to ventrals. Colora- 



