192 FISHES OF ILLINOIS 



state, we find this bullhead most abundant in the creeks of the 

 Mississippi bluffs and in the valleys of the Wabash and the Kas- 

 kaskia, 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. 



Generally speaking, it is not distributed so far to the northward 

 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 Jor- 

 dan to thrive in small ponds, particularly in those with a mud 

 bottom. 



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

 tion 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 distin- 

 guished 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 mol- 

 lusks made a fifth of the food, and river snails and aquatic insects — 

 the latter somewhat more than a fourth of the entire quantity — to- 

 gether 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 very common in the market catches, which 

 are usually made from the larger streams. 



This fish was spawning at Meredosia May 4, 1899. 



agree closely in this respect, we see in the distribution of these species evidence of 

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

 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 computation for natalis and nebulosus gives us a still smaller 

 associative coefficient (1.9). In other words, of these three pairs of species, the 

 yellow ami the brown bullheads are found least frequently 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. 



