Jordan and Evermann. Fishes of North America. 175 



developed, especially in the old males ; the free border of the dorsal deeply 

 incised. Height of each of the 3 vertical fins in the males greater than 

 the length of the head. Dorsal usually 11, sometimes 12 or 13, inserted 

 nearer snout than base of caudal. Caudal very strong, the rudimentary 

 rays at its base unusually developed ; least depth of tail less than \ the 

 head in males, stouter in females. Dark olive, abruptly paler below 

 sides and fins largely orange in both sexes, the anal and lower lobe of 

 caudal tuberculate in males. Herbivorous. L. 2 feet. Rio Colorado and 

 Rio Gila and their tributaries, very abundant, ascending the rivers in 

 spring. Variable, (latus, broad ; jnnna, fin.) 



Catostomiis laliphiiii*, BAIRD & GIRARD, Proc. Ac. Nat. Sci. Phila.,1853, 388, Rio San Pedro, Gila 

 Basin; GUNTHER, Cat., vn, 14, 18G8; JORDAN, 1. c., 178, 1878; JORDAN & GILBERT, Synopsis, 

 125,1883. (Tjpe, No. 20078.) 



Catostomus discobolus, COPE, Hayden's Geol. Surv. Wyo., 435, 1870, (young), Green River, 

 Wyoming. 



280. CATOSTOMUS GRISEUS, (Girard). 



Body long and slender, subterete, compressed behind, the form essen- 

 tially that of C. catostomus, the depth contained 5| times in the length. 

 Head large, 4 in length of body ; the interorbital space broad and flat, 2* 

 in length of head. Scales 16-90 to 110-14. Eye small, high up, and rather 

 posterior. Mouth large, about as in C. latipinnis, the upper lip pendant, 

 very large, with 5 to 8 series of tubercles ; lower lip incised to base, 

 lobes long; sheath pretty well developed. Dorsal fin not elongated, nor 

 especially elevated, its rays 10 to 12, usually 11, the beginning of the dorsal 

 rather nearer base of caudal than snout, much nearer in type of C. 

 retropinnis. Caudal fin long and strongly forked ; anal fin long and 

 high, reaching base of caudal; ventrals not reaching vent. Caudal 

 peduncle stout and deep, its least depth more than i length of head; its 

 length about $- that of head. Scales quite small, about as in C. catostomus, 

 the exposed portion not notably lengthened. Coloration dusky brown, 

 sometimes with a dusky lateral band, sometimes irregularly mottled or 

 barred. Snout quite dark. Size large. Platte River and upper Missouri 

 regions, very similar to C. catostomus, and perhaps not separated from it, 

 apparently differing chiefly in the larger mouth and broader upper lip. 

 Specimens from Gardiner River (Yellowstone Park) have larger scales, 88 

 to 90, representing a possible var. lactarius. (griseus, gray.) 



Acomus griseus, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 174, Sweetwater Fork of Platte 



River; GUNTHER, Cat., vn, 14, 1868. (Type, No. 20257.) 

 f Catoslomus lactarius, GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 174, Milk River, Montana; may 



be C. catostomus. 

 Catostomus retropinnis* JORDAN, Bull. U. S. Nat. Mus., xn, 178, 1878, Milk River, Montana; 



may possibly be a distinct species, distinguished by the fuller lips and more backward dorsal; 



it is probably an adult griseus. (Type, No. 21197.) 



281. CATOSTOMUS POCATELLO, Gilbert & Evermann. 



Head 4; depth 5 to 5; eye 4i to 5 (about 4 in young); snout 2i to 2 

 (2| in young); interorbital width 2f. D. 10 (rarely 9); A. 7. Scales 



*The type of C. retropinnis has very much larger lips than in any other specimens we have 

 examined, and the scales are smaller. It may be a good species. 



