The Food of Fishes. 
53 
These specimens were all from the Illinois River, in 
June, July, October and November. 
Food of the Adult. 
The twenty-four adults examined were from various 
parts of the State north of the center; and, as the food 
has been found to differ so widely according to the local 
situation, I have treated them in three groups — the first 
including those taken in the clear, inland, northern lakes ; 
the second those from Calumet River, at South Chicago, 
and the shallow, muddy lakes of that vicinity, and the 
third those from the Illinois River from Ottawa to 
Peoria. 
The specimens from the northern lakes were taken in 
May and June. Sixty- two per cent, of the food consisted 
of Neuroptera — -eight per cent, being a black caddis-fly 
( Sialis infumata ) and the remainder the larvae of large 
dragon-flies (Libellulidae), Agrions (eleven per cent.) 
and Baetis (two per cent.). Allorchestes dentata was the 
next most important element (twenty-seven per cent.). 
A number of terrestrial insects besides Sialis appeared 
in the food. These included a Harpalid beetle, an Apho- 
dius firnetarius , and some grasshoppers (Tettigidae, etc.). 
The second group of four, from Calumet River, and 
from Lake George, Indiana, was peculiar in the number 
of tetradecapod Crustacea and case-worms taken, and 
especially in the amount of vegetation eaten. 
The Crustacea were Allorchestes (thirty- two per cent.) 
and Asellus (twenty per cent.). The vegetation was pres- 
ent in such quantities as to make it evident that it had 
been taken as food. It amounted to about a fourth of the 
contents of these stomachs. The stomach of one fish was 
packed with a piece of the stem of a plant (apparently a 
Scirpus) a third of an inch in diameter and six inches 
long. Three others contained smaller amounts of con- 
fervoid Algae. 
The fifteen specimens remaining were taken from 'the 
Illinois in May, July, August, October and November. 
Their food was especially noticeable for the presence of 
