460 Illinois State Lahoyatorij of Natiinil Historj/. 



Seven immature examples, from two to three and a half 

 inches long, had fed chiefly upon Entomostraca, which made 

 about one half the food. Among these, Daphnia, Siinocephalus 

 americanus, Acroperus, Macrothrix laticornis^ Cyclops, and 

 Cypris were determined. One fourth the food consisted of the 

 univalve Physa, and one fifth of it of insect larvae, chiefly 

 ephemerids and Chironomus. A little Wolffia and other 

 aquatic vegetation likewise occurred. 



ICTALUEITS JSTEBULOSUS, LeS. BULL-HEAD ; HORNED-POUT. 



This superabundant species occurs in all waters and in all 

 parts of the state, but frequents by preference ponds and muddy 

 streams. It grows to a larger size in the rivers than elsewhere, 

 and has many marked varieties. Its feeding habits are appar- 

 ently essentially the same in all situations. 



Gill-rakers fourteen in number on the anterior gill, in one 

 row, thick, stout, not toothed, at the angle of the arch about 

 half as long as the filaments, shortening rapidly above and be- 

 low. Second gill also with a single row, shorter than those of 

 the first; succeeding gill with two rows each of still shorter 

 rakers, the posterior row shorter than the anterior ; a smaller 

 row upon the pharyngeal arch. The upper pharyngeals are 

 large and broad oval pads, with convex surfaces paved with 

 close-set, minute, sharp teeth, and act against the broad lower 

 pharyngeals, which are similarly armed. Intestine to head 

 and body as 1.2 to 1. 



Thirty -six specimens were collected for a study of the food, 

 — at Normal, Peoria, Pekin, and Havana, in Central Illinois ; 

 and from the Fox River and several of the small lakes in the 

 northern part of the state. The collections were made in May, 

 July, August, September, and October, of four different years. 



The vegetable food nearly equaled that of /. pundatiis, 

 and was taken by seven of the specimens. One had eaten dis- 

 tillery slops, and in the food of the others were found Cerato- 

 phyllum, Potamogeton, Chara, and various Algte. 



Fishes made one fifth of the food, — taken however by only 

 two of the specimens, which had eaten nothing else. One of 

 the fishes was a perch and the other a sunfish (Centrarchidae). 



