118 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



developed rays ranging from 23 to 30. Caudal fin well forked, the 

 lobes equal. Anal fin comparatively long and low, emarginate (in 

 males), its number of developed rays usually 8. Ventrals sbortisli, 

 with usually 10 rays. Pectorals short. Sexual peculiarities little 

 marked ; in some species, at least, the males in spring hove the snout 

 minutely tuberculate. Coloration always plain ; jiale olivaceous above, 

 white below, but hardly silvery, the fins all partaking of the color of 

 the region to which thej belong. Air-bladder with two chambers. 

 Size medium or rather large. This genus is very close to Ictiobus and 

 Buhalichthys. Its species are numerous and very difiicult to determine. 

 All belong to the United States. (Latin carpiodes, cari^-like.) 



* Dorsal fin with the anterior rays more or less shortened, their length one-half to 

 two-thirds that of the hase of the fin; muzzle more or less conic and pro- 

 jecting. 

 a. Head short, 4-5 in length. 



116. C carpio (Raf.) Jordan.— Ca)7) SucJcer. 



Head comparatively short, its length contained 4-5 times in the 

 length of the body. Body more fusiform than in the others, compressed, 

 but not much arched, the depth 2§-3 times in the 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 half the base of the 

 fiu; caudal moderately forked. Eye medium, anterior, 4i in head. 

 Muzzle short, but i^rojecting much beyond mouth. D. 30 ; Lat. 1. 36. 

 Size largest of the genus. Mississippi Valley ; generally abundant. 



{Catostomus carpio Rafinesque, Ichth. Oh. 1820,56; Jordan, 1. c. 200: Carpiodes tium- 

 mifer Cope, Proc. Amer. Phil. Soc. Phila. 1870,484.) 



aa. Head intermediate, its length contained about 4 times (3f-43t) in that of hodj^ ; 

 anterior rays of dorsal not thickened at base. 



IIY. C. tamidus B. & G. — Carp Sucker. 



Body elongate, not much elevated ; the depth 2^ in length. Head 

 3£— 4; the muzzle prominent, but rather bluutish. Front scarcely con- 

 cave above eyes, the profile forming a somewhat uniform curve. Eye 

 small, nearly G in head. Anterior rays of dorsal moderately elevated, 

 less than three-fourths the length of the fin ; the first ray nearly mid- 

 way between snout and base of caudal. Caudal lobes blunt ; subor- 

 bitals narrow, small. Scales 6-37-5 ; D. 24-27 ; A. 8 ; V. 10. Ohio to 

 the Eio Grande and Upper Missouri; common. Distinguished from 



