158 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY III. 



tapering rapidly from shonUlers to tail; intcrorbitnl space concave: length of hc«(l 

 jjrcater than depth of body."— (JounAX, Man. Vtrt. 1H7(), p. 292.) 



C.vTOSTO.MCS Cope & Jordan, 1877. — " Body oblong or elongate, with a short, snb- 

 qaadrate dorsal tin ; air bladder in two parts ; lateral lino well developed ; fontanelle 

 distinct."— (JoRD.w, rroc. Ac. Nai. Sc. Ph'tla. 1877, p. 81.) 



IlYrKNTEi.iu.M Jordan, 1878. — " Body oblong or elongate, with a short subqnadrate 

 dorsal; anal rays uniformly 7 ; mouth normal, the lower 11]) tindivided or deeply lobod ; 

 lips tuberculato; lateral line well developed; fontaiielh.' distinct; no mandibulary 

 sheath ; scales moderate, not crowded forwards, about equal over the body ; body long, 

 and little compressed; head transversely coEcave between orbits, long and flattened, 

 the physiognomy being therefore peculiar; ventral rays 9." — (Joun.vx, Man: Vert. ed. 

 2d, 1878, pp. :]09-310.) 



Catosto.mus Jordan, 1878. — [As in the preceding except] "Scales small, smaller 

 anteriorly and much crowded ; head transversely convex between orbits ; ventral 

 rays normally 10."— (Jordan, Man. Vert. ed. 2d, 1878, pp. :]09-:]10.) 



Dkcadactylus Jordan, 1878 (as subgenus). — "Lateral line with 00 to G5 scales; 

 snout comparatively short." — (Jordan, Man. Vert. ed. 2d, p. 319.) 



Catostomus Jordan, 1878 (as subgenus). — "Lateral lino with about 100 scales; 

 snout much produced." — (Jordan, Man. Vert. ed. 2d, p. 320.) 



The three subgenera here recoguized are characterized below. The 

 single species of IlijpcnicUum is found only eastward of the Kooky 

 Mountains. Catostomus and Decadactyhts each have representatives on 

 both sides of the mountains. It is a curious fact that the Southwestern 

 representatives of each, as a rule, have the upper lip more developed, 

 and with more numerous series of papillre, than the Eastern ones. In 

 this respect as in others, these Western species approach the genus Pan- 

 tosteus, a group exclusively Western in its distribution. 



ANALYSIS OF SPECIES OF CATOSTOMUS. 



• Scales moderate ; not crowded anteriorly, nearly equal over the body ; 48 to ;"> in the 

 lateral line; 12 to 15 in a transverse series from dorsal to 

 ventrals : head flattened above, transversely concave between 

 the orbits, the frontal bono thick, broad, and short, the phy- 

 siognomy being therefore i)eculiar: ventral rays normally 

 9: upper lip very thick, strongly papillose, with a broad, 

 free margin, which has upwards of 8 to 10 series of papillas 

 upon it. Lower lip greatly developed, strongly papillose, 

 considerally incised behind, but less so than in Catostomus 

 proper: fontanelle shorter and smaller than in Dccadactijhis : 

 pectoral fins unusually large. (Ilypentelium.) 

 X. Depth ■!* to ") in length ; head 4 to 4^ ; eye rather snuill, 4^ to .5 in head : color 

 olivaceous; sides with brassy lustre; belly white; back 

 brown, with several dark cross-blotches, irregularly arranged, 

 these becoming obsolete in old individuals; lower fins dull 

 red, with some dusky shading: size large; maximum length 

 about two feet nigricans, 24. 



