SEMOTILUS FALLFISHES 123 



an increase in its numbers is very noticeable as the headwaters are 

 approached. Within these limits its distribution in Illinois has been 

 quite general, including all our hydrographic divisions except the 

 Michigan drainage and showing no marked preponderance in any. 

 Outside this state it ranges far and wide throughout the central and 

 western United States, excepting, however, the Great Lakes and the 

 extreme southern and southwestern part of Our area. From the St. 

 Lawrence and its tributaries in Canada, and from New Brunswick, 

 Maine, and Vermont, it is found westward and southward through 

 the Hudson valley to the Potomac and the Roanoke, through the 

 Ohio and the Mississippi valleys to the Alabama River, and north- 

 westward to Wyoming. 



It is an active swimmer and exceedingly voracious, and with an 

 unusually varied diet for a minnow, including considerable quanti- 

 ties of vegetable food on the one hand, and small fishes on the other. 

 A fourth of the food of twenty-two specimens consisted of algas and 

 of miscellaneous vegetable debris. Four of these specimens had 

 eaten little else than filamentous algas, and three had captured 

 small fishes. Grasshoppers, caterpillars, ants, chrysomelid and 

 scarabagid beetles and various other terrestrial insects, together with 

 Corisa, dipterous larvae, and other aquatic forms, were the insects 

 represented, and three of our twenty-two specimens had eaten 

 only crawfishes. 



This species is reported by Jordan to reach a length of a foot, 

 and to be an excellent bait, when of the proper size, for bass, wall- 

 eyed pike, and pickerel. With the possible exception of Hybopsis 

 kentuckiensis , it is decidedly our gamiest minnow. It is always 

 ready to bite at a grasshopper, and will even rise to the fly. It 

 thrives in the aquarium, and with good treatment soon becomes so 

 tame as to feed from the hand*- 



Males in full breeding dress have been taken in our May collec- 

 tions. There are, in spring males, two large tubercles on each side 

 of the upper lip just below the nostrils, a row* of four other large ones 

 on each side of the eye, a cluster of minute tubercles on the lower 

 part of each opercle, and a row on the margin of most of the scales 

 on the upper part of the caudal peduncle. Reighard has seen a 

 male of this species preparing a nest by excavating the sand and 

 gravel in advance of spawning, but this is abandoned after the eggs 

 have been laid. 



*The eastern chub (Semotilus corporalis) does not occur west of the Alle- 

 ghanies. It is said by Atkins to spawn in May. It builds great heaps of gravel 

 in running water, but avoids eddies and ripples when spawning. The males 

 build the nest, carrying pebbles in their mouths. 



