FISHES OF COLORADO 3 1 



Body somewhat compressed, greatest depth 4 to s in the length to the base 

 of the caudal; back abruptly elevated just in front of the dorsal fin into a sharp- 

 edged hump which is borne by the enlarged interneural bones; head rather broad, 

 somewhat depressed, dorsal surface quite flat; length of the head 4 or a little less 

 in the length of the body; snout broad and blunt, overhanging the mouth; length 

 of the snout 2.5 to 3 in the head; nostrils large, prominent and double, the 

 dividing septum elevated; eye prominent, situated in the upper half of the head, 

 a little nearer to the tip of the snout than to the posterior margin of the oper- 

 culum; diameter of the eye 8 or 9 in the head; mouth large and ventral; median 

 indentation of the lower lip reaching the margin of the lower jaw, the two lobes 

 of the lower lip being distinctly separated at their junction with the lower jaw 

 by a median subtriangular space; upper lip with about 4 rows of papillae; 

 margins of the jaws rounded; dorsal fin high, its base about equal in length 

 to the head, of 12 to 15 rays, base of the first ray nearer to the tip of the 

 snout than to the base of the caudal; pectorals about i . 2 in the head, sepa- 

 rated from the ventrals by almost the length of the latter; ventrals nearly 2 in 

 the head, inserted below the eighth or ninth ray of the dorsal, not reaching 

 the anal opening; anal long, equalling or slightly exceeding the length of the 

 pectorals, its base short, being about one-half the length of the longest ray, of 

 7 rays; caudal large, broad and rather deeply forked, its width equalling the 

 greatest depth of the body; scales 13 to 15, 70-86, 13 or 14. 



General color bluish gray to olivaceous; top of the head and anterior por- 

 tion of the hump quite dark; dorsal color extending well down on the sides, fading 

 gradually to silvery white below. Size large, length often over 20 inches. 



This species is distributed quite generally throughout the Colorado River 

 drainage in the large streams below the foothill region. Because of their large 

 size the adult Humpbacked Suckers are often marketed with the Flannel-mouthed 

 Suckers. Professor Junius Henderson has told the writer that X. texanus is taken 

 in numbers by the Mohave Indians from the Colorado River near Fort Mohave. 



Colorado specimens. — University Museum: Grand River, Grand Junction, August 7, 1912 

 (3 specimens. 290-400 mm.), J. Henderson and M. M. Ellis, No. 325. 



Family CYPRINIDAE 

 The Minnows and Carp 

 Mouth without teeth, teeth on the pharyngeal bones generally weU developed; 

 head naked, body usually scaled; barbel present or absent; air bladder with a 

 ductus pneumalicus; fresh-water species. 



The species of this family are very numerous, considerably over i ,000 being 

 known at present. They are found in the fresh waters throughout the world 

 with the exception of those of South America and Australia. The family is 

 divided into several large groups all of which intergrade more or less; by some 



