193 FISHES OF ILLINOIS 



different sections of the state, we find this bullhead most abun- 

 dant in the creeks of the Mississippi bluffs and in the valleys of 

 the Wabash and the Kaskaskia, where its ratios of frequency, 

 mentioned in the above-named order, are 1.23, 1.58, and 1.71. 

 We have found it least abundant in the streams of the Michigan 

 drainage. 



General^ speaking, it is not distributed so far to the north- 

 ward or eastward as our other abundant bullheads. Its range 

 extends from the Genesee River in New York through the Great 

 Lakes of Ontario, Erie, and Michigan to the Missouri basin, 

 which it seems to occupy thoughout, and thence southward to 

 Kansas, Alabama, and Texas. It is especially abundant west 

 of the Mississippi. It is said by Jordan to thrive in small 

 ponds, particularly in those with a mud bottom. 



When the studies on the food of fishes from which our infor- 

 mation on that subject is chiefly drawn, were made by the senior 

 writer in 1888, this species was not clearly distinguished from the 

 brown bullhead, nebulosus, and the statements made under the 

 latter head relate in part to the present species. The food of 36 

 specimens, doubtless composed of these two species commingled, 

 is distinguished by the fact that nearly a fourth of it consisted of 

 aquatic vegetation of various kinds, including distillery refuse 

 eaten by one of the fishes. Two of these bullheads had filled 

 themselves with other fish, a sunfish and a perch among them. 

 Small bivalve mollusks made a fifth of the food, and river snails 

 and aquatic insects^the latter somewhat more than a fourth 

 of the entire quantity — together with crawfishes and other 

 crustaceans, were the other more important elements. 



The habits of the species are, so far as known, very similar to 

 those of the brown bullhead. It is of smaller size, and, owing 

 to its local distribution, is not ver}^ common in the market 

 catches, which are usually made from the larger streams. 



This fish was spawning at Meredosia May 4, 1899. 



evidence of two methods of avoiding competition over the same territory, one by a difTerence 

 of preference as to size and kinds of waters inhabited {natalis and nebulosus) and the other by 

 a difference in the kinds of situations chiefly frequented {natalis and melas). A similar com- 

 putation for natalis and nnbidosus gives us a still smaller associative coefficient (1.9). In other 

 words, of these three pairs of species, the yellow and the brown bullheads are found least fre- 

 quently, in the same kinds of waters, and least frequently also in the same situations; the black 

 and the yellow bullheads are found most frequently in the same kinds of waters, but with medium 

 frequency in the same situations; and the yellow and the brown species are found least frequently 

 in the same waters, but most frequently associated in the same situations. 



