166 Bulletin 47, United States National Museum. 



short. Sexual peculiarities little marked; in some species, the males in 

 spring have the snout minutely tuberculate. Coloration always plain ; 

 pale olivaceous above, white below, but hardly silvery, the fins plain. 

 Air bladder with two chambers. Size medium or rather large. This 

 genus is very close to Ictiobus and its species are even more difficult to 

 determine. Compared with Ictiobus, the Carpiodes are smaller in size 

 and paler in color, with weaker dentition, but no technical character of 

 importance separates the 2 groups. (Carpio, eldo$, carp-like.) 



a. Body subfusiform, the depth about 3 in length ; lips thin, silvery white in life, the halves 

 of the lower lip meeting at a wide angle. CAEPIO, 2G5. 



aa. Body ovate oblong, the back elevated, the depth about 2% in length. 

 6. Opercle strongly striate. 



c. Lips thin, silver-white in life, the halves of the lower lip meeting in a wide angle, 



as in C. carpio. 



d. Head large, with blunt snout, the nostril near its tip ; eye large, 3^ to 4 in 

 head. DIFFORMIS, 266. 



dd. Head small and pointed, the snout projecting ; eye small, 5 to 5% in head. 



THOMPSONI, 267. 



cc. Lips full, thick, reddish in life, the halves of lower lip meeting in an acute angle; 



first ray of dorsal usually very long. VELIFER, 268. 



bb. Opercle nearly smooth ; otherwise essentially as in C. velifer. CYPBINUS, 269. 



265. CARPIODES CARPIO, (Rafmesque). 



(CARP SUCKER.) 



Head comparatively short, its length 4 to 5 times in length of body. 

 Body more fusiform than in the others, compressed, but not much arched, 

 the depth 2- to 3 times in length. Anterior rays of dorsal short, notably 

 thickened and osseous at base, especially in the adult ; the first ray nearer 

 the end of the muzzle than the base of the caudal fin, the longest ray a 

 little more than i the base of the fin ; caudal moderately forked. Eye 

 medium, anterior, 4| in head. Muzzle short but projecting beyond mouth. 

 D. 30. Lat. line 36. Size largest of the genus. Ohio Valley; southwest to 

 central Texas, generally abundant, apparently a valid species but varia- 

 ble, and its synonymy uncertain. Perhaps more than one species is here 

 included, (carpio, carp.) 



fCatostomus carpio,* BAFINESQUE, Ichth. Oh., 56, 1820, Falls of Ohio River. 

 Carpiodes nummifer, COPE, Proc. Am. Phil. Soc. Phila., 1870, 484, Wabash River. 

 Carpiodes carpio, JORDAN & GILBERT; Synopsis, 118, 1883; JORDAN & GILBERT, Proc. U. S. Nat. 



Mus., 1886, 20; Texas specimens. 

 f Carpiodes Hsonrf AOASSIZ, Am. Jour. Sci. Arts, 1854, 356, Osage River. 



266. CARPIODES DIFFORMIS, Cope. 



Snout very blunt, the maxillary reaching to front of the pupil. Nostrils 

 very near tip of snout, above or below upper lip; lips thin, silvery colored 



*The following is Rafinesque's description: "Diameter % of the length; olivaceous above, 

 pale beneath, chin white; abdomen bluish; lateral line straight; dorsal fin somewhat falcated 

 with 36 rays; anal trapezoidal with 10 rays; head sloping, rounded. Seen at the Falls of the 

 Ohio, commonly called Carp. Length from 1 to 2 feet. Eyes very small and black; fins oliva- 

 ceous brown, the pectorals olivaceous, trapezoidal, short, and with 16 rays; tail with 24. Dorsal 

 beginning before the abdominal and reaching the end of the anal fin. Not so good to eat as the 

 Buffalo fish." 



fThe following is Agassiz's description: "More elongated than C. laurus. Thehead issmaller; 

 the opercle also smaller and the subopercle triangular. The dorsal has its anterior rays longer, 

 hence its hinder border is more deeply emarginate. Anal more lunate. Horizontal diameter of 

 scales greater." 



