112 FISHES OF ILLINOIS 



proper treatment, fragments of organic matter could be readily 

 separated. This was nearly all of vegetable origin, chiefly 

 filamentous algae, with diatoms, and minute fragments of vari- 

 ous kinds of plant tissue. Sometimes the intestine was filled 

 with almost pure mud. 



Dr. Jordan says of this species that "it spawns early in 

 spring, and it ascends in great numbers all the running streams 

 even the very smallest. Later it retires to the deeper places in 

 the creeks, where it may be readily recognized by its quick 

 motions and dusky colors. Most of the specimens seen are 

 comparatively small, but occasionally an old male may be 

 noticed in the spring with its entire body rough and gray with 

 tubercles, and with its vertical fins gaily variegated with black 

 and orange. Such individuals appear to have exhausted their 

 vitality and die quickly in confinement, and are often found 

 dead. Young individuals are active and hardy in the aquarium, 

 where they feed on confervas and diatoms. " 



This minnow is unusually tenacious of life, being among the 

 hardiest of the aquarium fishes and extremely persistent on the 

 hook. It is regarded by anglers as one of the best of live baits 

 for black-bass fishing. Males in breeding dress and females 

 apparently near spawning have been found by us from Novem- 

 ber 15 to December 15 in fall, and from May 1 to June 15 in 

 spring. Breeding males often have the head and almost the 

 entire body tuberculate. According to Dr. Reighard, an ex- 

 cavation is made by the male in sand or gravel in advance of 

 spawning. 



Genus CHROSOMUS Rafinesque 



Body moderately elongate; not much compressed; no barbel; jaws 

 normal; premaxillaries protractile; teeth 5-5 or 4-5, moderately hooked, 

 with 4 well-marked grinding surface; alimentary canal twice length of body; 

 peritoneum black; dorsal rays 7 or 8; anal rays 9; scales small, 67 to 85 in 

 lateral series; lateral line imperfect or wanting; size small, not over 3 inches. 

 Three species; New England to the Dakotas, chiefly northward. 



CHROSOMUS ERYTHROGASTER Rafinesque 

 red-bellied dace 



(Map XXIV) 



Rafinesque, 1820, Ichth. Oh., 47 (Luxilus), 48. 



G., VII, 247 (Leuciscus); J.' & G., 153; M. V., 53; J. & E., I, 209; N., 47; J., 61; F., 

 79; F. F., I. 6, 80; L., 14. 



The minute scales, 77 to 91, in the lateral line, and the two longitudinal 

 stripes of dark color upon the sides, will readily distinguish the present species 



