The Food of Fishes. 
47 
Ambloplites rupestris, Raf. Rock Bass. 
This favorite and widely distributed species does not 
differ from the other fishes mentioned in respect to the 
food of the young. The smallest specimen examined, five- 
eighths of an inch long, contained only a few Cladocera 
(Pleuroxus). Another, three-fourths of an inch long, had 
eaten Daphnids (seventy-five per cent.), Cyclops (ten per 
cent.), and larvae of Chironomus. A third, seven-eighths 
of an inch long, contained only minute fragments of a few 
larvae of Neuroptera. These specimens were all taken 
from Fox River in July, 1879. The remaining young of 
the year were living chiefly on Corixa (eighty- three per 
cent.), as were also the young of the year preceding 
(ninety per cent.), so far as could be judged from the 
food of two specimens, from three to four inches in 
length. Some land insects, ephemerids, water-beetles, 
and a few Allorchestes were also found in the food. 
Four adult specimens, taken at Ottawa on the 8th of 
July, had eaten some minute fishes (fifteen per cent.), a 
few water-beetles, including Tropisternus limbatus , over 
forty per cent, of Neuroptera larvae, and about thirty per 
cent, of small crawfishes. The Neuroptera included 
Baetis and other ephemerids (twenty per cent.), Agricn 
idae and large Libellulidae, and fifteen per cent, of case- 
flies (Phryganeidae). Pond-weed (Potamogeton) found 
in two stomachs, had probably been taken accidentally. 
Ch^nobryttus gtjlosus, C. & V. Wide-mouthed Sunfish. 
This fine species is among the commonest of the family 
in the lakes and ponds of southern Illinois, where it is 
commonly known as the 4 ‘ goggle-eye. ” 
The northern limit of its range, so far as known, is the 
Illinois River valley. In number and habitat it replaces 
in the south the Eupomotis aureus of the north ; but this 
equivalence is only apparent as the two species differ 
widely in food. From its size and abundance, it is no in- 
significant food resource. 
Food of the Young. 
My smallest specimens were from lakes in the Mississip- 
