The Food of the Smaller Fresh- Water Fishes. 89 



oceurriiiir in two of the specimens. Numerous examples of 

 Gordiiis were found in two, and were reckoned at three per cent. 

 of the food.* The vegetable food (twenty-four per cent.) was half 

 Alga', the remainder miscellaneous vegetable debris. 



Eight had eaten only insects, two having filled themselves with 

 grasshoppers. Three from a prairie stream near Normal had taken 

 only crawfishes, while of four specimens captured in McLean 

 County in July, filamentous Algte composed ninety-four per cent, 

 of the food. 



Ckratichtiiys higuttatus, Kirt. Horned Chub. 



This species is everywhere abundant northward, chi(illy, like 

 Semotilus, in the smaller streams, but preferring swifter waters. 

 We have not taken it, however, south of the center of the State. 



It differs from the preceding members of the group by the 

 greater length of its alimentary canal, which considerably exceeds 

 the head and body, the latter being contained in the intestine 

 about one and one-fourth times. The gill-rakers are not peculiar. 



Thirteen specimens from Northern and Central Illinois had 

 derived less than' half their food from the animal kingdom. Only 

 about one-fourth of it consisted of insects, largely case-worms and 

 other neuropterous larva?, another fourth being Crustaceans 

 (crawfishes), eaten, however, by only two of the specimens. The 

 vegetable food (fifty-four per cent.) was about equally divided 

 between filamentous Alg;v and seeds of Setaria and other grass- 

 like plants. 



Notwithstanding tlie small ratio of insects figured out, it is 

 worthy of note that two specimens out of four captured in a creek 

 in September had eaten only insects, chiefly case-worms, while 

 these composed ninety-five per cent, of the food of another. As 

 the intestines of these fishes contained a consideral)le quantity of 

 gravel, it is ^evident that they had fed upon the bottom in rather 

 swift water. On the other hand, two specimens had derived all their 

 food from vegetable sources, and three others had eaten eighty 

 per cent, or more of vegetation. The extraordinary amount of 

 vegetation in the food of tliis fish is possibly related to tlie 

 increased length of the alimentary canal. 



*These were not from the same specimens as those containing the 

 grasshoppers. 



