118 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY - IV. 



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

 lobe> eipial. Anal tin comparatively long and low, emarginatc (in 

 males), its number of developed rays usually 8. Veutrals shortish, 

 with usually 10 rays. Pectorals short. Sexual peculiarities little 

 niarknl; in sonic species, at least, the males in spring ho ve the snout 

 minutely tuberculate. Coloration always plain; pale olivaceous above, 

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

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

 Si/e medium or rather large. This genus is very close to Ictiobus and 

 ];nl><il!<-ltih>/s. Its species are numerous and very difficult to determine. 

 All belong to the United States. (Latin carpiodcs, carp-like.) 



* Dor>al I'm with the anterior rays more or less shortened, thoir length one-half to 

 1 \vo-thirds that of the base of the fin; muzzle more or less conic and pro- 

 jecting. 

 a. Head short, 4-5 in length. 



116. C. carpio (Raf.) Jordan. Carp Sucker. 



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 2g-3 times in the length. Anterior 

 rays <>t' dorsal short, notably thickened and osseous at base, especially 

 in the adult; the first ray nearer the end of the muzzle than the ba^e 

 of the caudal fin, the longest ray a little more than half the base of the 

 I'm; caudal moderately forked. E}'e medium, anterior, 41 in head. 

 Miix/.le short, but projecting much beyond mouth. D. 30; Lat. J. 36. 

 Si/.e largest t' the genus. Mississippi Valley; generally abundant. 



ciirj>:n R:iliiii's(|iii', Ichfh. Oh. 1820,50; Jordan, 1. c. 200: Carpiodcs tnim- 

 ( ope, Proo. Amer. 1'hil. Soc. Phila. 1870,4*4.) 



ll'iid intermediate. its length contained about 4 times (3J-4J) in that of body ; 

 anterior rays of dor>al not thickened at ba>e. 



I 1 7. C. tilinadus 15. & G.Carp 



llmly elongate, not much elevated ; the de]>tli L >: < in length. Head 

 .'r, 1 -!; the muzzle prominent, but rather bluntish. Front scarcely con - 

 oave above eyes the proiile forming a somewhat uniform curve. Kye 

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

 !-> than three-fourths the length of the I'm : t lie first ray nearly mid- 

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

 bilals narrow, small. Scales ({-.",7-5; I). LM-L'7 ; A. 8; V. 10. Ohio to 

 the Uio Cii-ande and rjijier Missouri ; common. Distinguished from 



