78 FISHES OF ILLINOIS 



orbit; mouth wholly inferior, not quite so wide as in the last species, the 

 lips somewhat thicker, weakly plicate, the halves of lower meeting at 

 a rather sharp angle; tip of lower lip scarcely in advance of nostrils; 

 interorbital space 2.2 to 2.S in head; eye larger than in other species 

 of Carpiodes, 3.9 to 4.6 in head, usually but little more than 4. Dorsal 

 rays 24 to 25, the first rays rather osseous at base, but not so robust as 

 in carpio, and as a rule much elongated, sometimes exceeding in length 

 the base of the fin. Scales large, 6-7, 35-37, 6, usually 35 or 36, rather 

 loosely imbricated; lateral line complete, nearly straight. 

 Males with snout tuberculate in spring. 



Ohio Valley and westward ; generally common. Common in our 

 'collections, seeming to prefer the shallow waters of the smaller 

 streams, where the young are often found in large numbers; adults 

 taken sparingly in the Illinois and Rock rivers. 



Represented in 102 of our collections, more than half of which 

 are from creeks. We have found it less frequent in the larger than 

 in the smaller rivers, and still less so in lakes and ponds. The size 

 is small and the species is of little value as food. It is abundantly 

 distributed throughout central Illinois, but has occurred less com- 

 monly in our southern Illinois collections, and is absent from the 

 most of those made in the extreme northern part of the state. 

 It apparently avoids in great measure the lower Illinoisan glacia- 

 tion, having been taken but five times by us within that area. 



CARPIODES VELIFER (Rafinesque) 

 (quillback; silver carp) 



Rafinesque, 1820, Ichth. Oh., 56 (Catostomus). 



J. & G., 118 (tumidus), 119 (cyprinus); M. V., 45 (Ictiobus); J. & E., I, 167; N., 49 

 (Ichthyobus) ; J., 65; F., 81 (Ictiobus cyprinus, part); L., 12. 



Body ovate, compressed, back much arched in adults; ventral line 

 almost straight; depth 2.7 to 3 in length. Size small, seldom exceeding 

 12 inches. Color light olive above, sides silvery, fins pale. Head 

 moderate, its length 3.6 to 4, depth 4.3 to 5.2, width 6 to 6.7 in length of 

 body; snout long, bluntly pointed, as in last species, 2.9 to 3.5 in head, 

 usually less than 3.2 ; nostrils well back, distance from anterior opening 

 to end of snout greater than diameter of eye; mouth rather narrow, 

 slightly oblique, tip of lower lip far in advance.. of nostrils; lips weakly 

 plicate, rather thick, the lower halves meeting in a sharp angle; inter- 

 orbital space 2.3 to 2.5 in head; eye small, 4.8 to 5.5 in head. Dorsal 

 rays 27 to 30, usually 27, the anterior ravs slender and elongate, some- 

 times longer than base of fin. Scales 7, 39-40, 6; lateral line complete, 

 usually somewhat flexuose. 



