JORDAN ON FISHES OF DAKOTA AND MONTANA. 781 



Genus CATOSTOMUS Le Sueur. 

 4. — Oatostomus eeteopinnis Jordan, sp. nov. 



This species belongs to the subgenus of typical Catostomus. It is 

 therefore related to G. latipinnis, C. longirostris, and C. taJioeyisis, and 

 may be briefly characterized as having the body, scales, dorsal and 

 ventral fins of longirostris, with the mouth and lips of latipinnis. Its 

 nearest relations are, I think, with latipinnis, with which species it is 

 compared below. 



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

 fore essentially that of G. longirostris^ the depth contained 5 J times in the 

 length. Head large, long, its length contained about four times in the 

 total length without the caudal fin (4J in latipinnis) ; interorbital space 

 broad and flat, about 2^ times in length of head; eye small, high up, 

 and posterior, entirely behind the middle of the head (near the middle 

 in latipinnis) ; preorbital bone very long, its length about three times its 

 depth (scarcely twice in latipinnis) ; the snout correspondingly pro- 

 longed; fontanelle quite small; mouth very large, formed as in latipin- 

 nis, but rather broader and not so long; upper lip pendent, very large, 

 with a broad, free border, with 5 to 8 series of low tubercles, almost 

 obliterated in the type-specimen, on account of the softening of the 

 skin; lower lip very full, its posterior margin reaching to the nostrils 

 (rather farther in latipinnis). 



Dorsal fin not large, its rays I, 11 (I, 13, in latipinnis); its base about 

 three-fifths the length of the head (five-sixths in latipinnis); its insertion 

 unusually backward, much nearer base of caudal than the tip of the 

 snout (much nearer the snout in latipinnis) ; caudal fin large, well forked, 

 its rudimentary basal rays not greatly developed ; anal fin long and high, 

 reaching base of caudal ; ventrals not reaching to vent (to vent in lati- 

 pinnis) ; pectoral fins long. 



Caudal peduncle rather stout and deep, its least depth more than 

 one-third head (less than one-third in latipinnis); its length about 

 two-thirds that of head (seven-eighths in latipinnis). In latipinnis, the 

 caudal peduncle is notably long and slender. 



Scales quite small, about as in longirostris^ larger behind, the exposed 

 portion not notably lengthened as in latipinnis: chest with well-de- 

 veloped scales (these rudimentary and imbedded in latipinnis). 



The type is a large specimen, 16f inches long ; a male, as is shown by 

 the presence of tubercles on the anal and caudal fins, a fact confirmed 

 by dissection. In coloration, it is rather dark, with traces of a dusky 

 lateral band, which passes around the snout. This specimen is num- 

 bered 21197 on the Eegister of the National Museum. 



Another specimen of this species is in the National Museum, from 

 Platte Eiver. It was identified by me as the female of C. latipinnis, the 

 numerous differences in form being supposed to be sexual. As the 



