The Relation of Mollusks to Fish in Oneida Lake 193 
No. 5 (309). 98 mill. long. 
Insecta. 13 chironomid larve......... 100 per cent. 
PRE-ADULT, 100-125 mill. long. 
No. 6 (309). 113 mill. long. 
Crustacea. Camobarus, claw 7 mill. long. 20 per cent. 
Finely macerated matter.............. 80 per cent. 
INOS (809). 115 mill long. 
Crustacea. Cambarus, fragments...... 25 per cent. 
Miaicerated -matber —ocpae ata se -cbeia os 75 per cent. 
No. 8 (309). 125 mill. long. 
Insecta. Dragon-fly nymph, fragment. . 
per cent. 
Macerated matter 
per cent. 
Aputr. 125-200 mill. long. 
No. 9 (309). 200 mill. long. Stomach empty. Intestine filled with 
jelly-like matter. 
No. 
bo 
Length unknown, but fish adult (only stomach contents 
available). 
Mollusca. 1 Musculiwm securis ...... 10 per cent. 
Crustacea. I Combanus:.. «asc s oe e 40 per cent. 
Pisces. IPsmallensh soem see 50 per cent. 
No. 1 (145). 200 mill. long. 
Stomach and intestine empty. 
As noted by Forbes (1880, a, p. 29) in his study of Illinois 
fishes, the food of the Perch of Oneida Lake changes in 
character as the fish increases in age. !nsects and Entomw- 
straca form the food of fish under 100 mill. in length. This 
may be expressed by the following ratios: 
IS CCU ARR neh ae cay Shh esta epecat myst tre aryl ioe aps 43.13 per cent. 
Crustacea, —Hntomostraca sss. -). «4-4-6. 5. 15.62 per cent. 
RtuyNChMmING AGS. 0.0: 35's ras Seas > AT a 11.88 per cent. 
Mecerated Mather asses On. A eenen ee mis, 2. 39.37 per cent. 
A class of sizes, 100-125 mill., is here designated as pre 
adult, in which crawfish first appear, and before fish or 
mollusks are user as food. These afford ratios of : 
UISUAGea. CRAWLS 22. ney cesegs ous 'heyedsyausiete:« 15.00 per cent. 
LN TRSYC ET ea ee TARE Re a tn gehOene Go baieS Solan Smee 25.00 per cent. 
Miacerateds matter. cratic s te tke says s Geis 60.00 per cent. 
fi 
