(H) 



In summing up, all the notes on the food of each species were collated, 

 and an attempt was made to arrange the essential facts in a compact and 

 simple form. The classification of fishes used is that of the preceding paper 

 on the fishes of Illinois. 



RESULTS. 



Only a mere beginning has as yet been made. One hundred and forty- 

 nine specimens have been examined, representing fifty-four species — taken 

 chiefly (except the minnows) from the Illinois River, near Peoria and Henry, 

 in June and November, 1877, and April and May, 1878. The specimens 

 were all of a fair average size. In this preliminary report upon so small a 

 number of specimens, it has not been deemed worth while to specify dates 

 and places. 



When the facts relating to any species are numerous and varied enough 

 to make systematic condensation desirable, the articles of food have been 

 arranged according to the natural classification of plants and animals, in 

 such a way that one wishing to know only the general conclusions reached 

 can readily learn them, without being embarrassed by unessential details. 



The importance of a knowledge oi the proportiom of the different ele- 

 ments of the food has been kept in mind, and an attempt made to indicate 

 these rudely by placing after each the number of specimens of the species 

 in which the given element was found. Thus, under Lepiopomus pallidus 

 (No. 18), of which two specimens were examined, " Chrysomelidae 2" in- 

 dicates that one or more beetles of this family were found in the stomachs of 

 each of tivo specimens of that species. The figures in parentheses placed 

 after the family and specific names of fishes indicate the number of speci- 

 mens examined. 



DETAILS OF FOOD. 



DARTERS. ETHEOSTOMATIDAE. [9.) 

 Entomostraca and larvae of diptera and neuroptera. 



1. Sand Darter. Pleurolepis pellucidus, Ag. (2.) Larvae of small 

 diptera. 



2. Black-sided Darter. Alvordius maculatus, Grd. (1.) Small dip- 

 tera (gnats), larvae of May-flies (^Ephemeridae), and many unknown minute 

 eggs ?, oval, tuberculated, with tubercles in longitudinal rows. 



3. Johnny Darter. Boleosoma maculata, Ag. (1.) Several Cyclops 

 and many larvae of gnats. 



4. Banded Darter. Nanostoma zonalis. Put. (1.) Larvae of gnats, 

 including some with antennae similar to those of Corethra pictipennis. 



