52 
. The Food of Fishes. 
gust, September and October, at Pekin, Peoria, and Mack- 
inaw Creek, Woodford county. Neither locality nor date 
seems to have made any marked difference in their food, 
the principal elements of which were Entomostraca and 
Chironomus larvae — fifty-seven per cent, and thirty-seven 
per cent, respectively. 
A few water-spiders (Hydrachnidae) and undetermined 
Amphipoda were the other items. The Entomostraca 
were all Cyclops (twenty per cent.) andCladocera ( Simo - 
cephalus vetulus and americanus, Bosmina longirostris 
and Pleuroxus dentatus). 
Nine specimens, between two and three inches long, 
were caught at the same times and places as the preced- 
ing, except that one specimen from Mackinaw Creek was 
taken in June, and one taken in September was from 
Clear Lake, Kentucky. The greater size of these speci- 
mens was indicated by the appearance of a few Neurop- 
tera larvae in the food — -eight per cent. In other essential 
respects, the food was like that of the foregoing group. 
One specimen had eaten largely of water-mites and an- 
other of Cyprids (fifty per cent.), and these elements 
have therefore greater prominence in the averages. Chi- 
ronomus larvae paid Entomostraca now sum up eighty- 
one per cent. 
In the third group of the young, consisting of seven 
fishes, between two and three inches long, the Chirono- 
mus larvae remain about as before (thirty per cent.), 
Corixas appear (twenty-five per cent.) and Neuroptera 
larvae rise to fourteen per cent. Entomostraca now fall 
away to a trifle, and larger percentages of Amphipoda 
appear. Single fishes had eaten the larvae of a Gyrinid 
beetle, portions of the Polyzoan Pectinatella magnified * 
Leidy, and an earthworm — the latter probably nibbled 
from some fisherman’s hook. 
* This animal forms the large, translucent masses found in midsummer 
in the slow water along the margins of the Illinois River and elsewhere 
throughout the state, usually collected about a stick or a stem of a water- 
weed. They vary from the size of a walnut to that of half a bushel. 
The fragments were easily recognized by the peculiar form and armature 
of the winter eggs (stat.oblasts), which are discoidal and bordered with a 
row of slender double hooks, shaped something like an anchor. 
