The Food of Fishes. 
51 
tomostraca from the food, the larger size of the insects 
taken, and the appearance of fishes and crawfishes. 
Among the insects were a large Hydrophilus unknown 
to me, but nearly as large as H. triangularis , the larva of 
Corydalus cornutus, of Libellula and of some Ephem- 
erid. The fishes composed about thirty-six per cent, of 
the food. The only recognizable specimens were a small 
Cyprinoid and a young buffalo-fish ( Ichthyobus bubalus). 
Crawfishes and the river shrimp (Pahemonetes) had 
been eaten by two of the specimens. 
Lepiopomus pallidus, Mit. Common Sunfish. 
This abundant, hardy and voracious species, is- found 
throughout the State, and may be regarded as the typical 
sunfish. It is most plentiful in the larger rivers in cen- 
tral Illinois, being replaced in ponds by Apomotis cyan- 
ellus. 
Consistently with its wide range and varied habitat, it 
is a general feeder for a sunfish — peculiar only in the 
fact of its strictly non-predaceous character. Of forty- 
five specimens examined, only one had eaten a fish, and 
that one only a single small darter. 
Undifferentiated C entra rchidae.—I introduce here the 
food of six specimens of this family which were too small 
for determination. They were too deep for Micropterus, 
and as they had but three anal spines, could not have 
been Ambloplites or Pomoxys. They were probably Lep- 
iopomus pallidus. All were taken from the Illinois River 
— a part of them near La Salle, in July, 1879 — the others 
from Peoria, in June, 1878. 
The smallest (seven-sixteenths of an inch long) had 
eaten only Daphniidae. The next in size (one-half inch) 
contained Cyclops (ninety-eight per cent.) and Chydo.rus. 
Nearly the whole of the food of the remaining four was 
Daphniidae (ninety-four per cent.), including Daphnia 
pulex. 
Food of the Young. 
My smallest specimens, five in number, ranging 'from 
three-fourths of an inch to one inch, were taken in An- 
