The Relation of Mollusks to Fish in Oneida Lake 181 
Crustacea. 1 amphipod, Hyalella knicker- 
GOCRCIAL scceh ettg fe pine tee So oe ade wD oinls « 20 per cent. 
No. 2 (101) 52 mill. long. 
Insecta. 9 adult midges, fragments...... 100 per cent. 
No. 3 (101) 51 mill long. 
Insecta. 17 adult midges, fragments..... 89.50 per cent. 
ACATINA 2) WCET INVES sss) ar-u5 one easeainr= > ol << .50 per cent. 
Crustacea. 74 Entomostraca (Bosmina 
LONGIT OSES). sks acca cee ere 9.00 per cent. 
Bryozoa. 20 statoblasts of Plumatella.... 1.00 per cent. 
No. 4 (101) 55 mill. long. 
Insecta. 5 adult midges, fragments...... 100 per cent. 
The average for four specimens is insects, 92.38 per cent. ; 
crustaceans 7.25 per cent.; Acarina and Bryozoa .37 per 
cent. 
Ambloplites rupestris (Rafinesque). Rock Bass; Red Eye. 
Forbes (1880, a, p. 44) found the food of four adult Rock 
Bass to consist of small fishes, 15 per cent.; Neuroptera, 
Odonata, ete., 40 per cent., and crawfishes 30 per cent. 
Three young fishes had fed on Entomostraca and a few insect 
larve. Hankinson (1908, p. 210) found the Rock Bass in 
Walnut Lake, Mich.. to feed largely on crawfish. Nineteen 
specimens gave the following results: Crawfish in 10; 
dragon-fly larvee in 6; midge larvee in 2; small fish in 1; 
May-fly larvee in 1. Reighard (1915, p. 231) examined 17 
specimens, finding a small fish in one, a crawfish in a second 
and Cambarus virilis and dragon-fly larve in another. Mar- 
shall and Gilbert (1905, p. 518) examined 16 specimens, 13 
of which contained food; in 2 insect larvee were found, and 
in 12 crawfish were found. Of the Oneida Lake specimens, 
3 out of 5 had eaten crawfishes. It seems evident that this is 
the favorite food as 30 out of 39 specimens had eaten this 
animal. In the spring the food consists mostly of the larvee 
of insects, crustaceans, and worms. In summer and fall the 
food appears to consist principally of crawfish. 
The data for the Oneida Lake records is given below. Nos. 
1-2, collected on Grass Island bar in trap nets, Sept. 9, 1915, 
