The Food of Fishes. 
41 
a few Daplmias. The fourth, one and seven-eighths 
inches long, caught at Peoria, in October, had eaten only 
larvae and pupae of Chironomus. 
The two adult specimens were feeding chiefly upon the 
larvae of Neuroptera — especially May-flies. An Allor- 
chestes dentata and a few small grasshoppers also ap- 
peared in the food. 
It will be seen that this species apparently agrees 
closely with the preceding in its food. The large amount 
of crustacean food in the smallest specimen shows that 
we should probably find still smaller Labracidae depend- 
ing upon these as strictly as the Percidae. 
Family CENTRARCHIDAE. The Sunfishes. 
This interesting group, known, in some of its members, 
to every one who has ever seen a dozen fishes, is repre- 
sented in Illinois by sixteen species, as the species of this 
family are now understood. The two black bass, included 
in this family for technical reasons, are, of course, the 
most important species. The rock bass, the croppie and 
the common sunfish (Lepiopomus pallidus), although not 
fishes of the first class, would be seriously missed if we 
were to lose them; and boyhood in the country would be 
quite another thing if it were not for the “pumpkin- 
seed” in the mill-pond, whose barbaric splendor thrills 
the heart of the youthful fisherman as the more delicate 
beauties of the trout or salmon do those of tougher fibre. 
I have studied the food of thirteen species of this 
group, as indicated by two hundred and thirty-seven 
specimens, well distributed in time and area. 
Decided differences in food made out in the various 
genera, have been found to coincide with differences in a 
few structures about the mouth in such a way that one 
may predict, from an examination of these structures, 
what the leading peculiarities of the average food of any 
genus will be. 
Micropterus pallidus, Raf. Large-mouthed Black Bass. 
This famous species is too well known to require ex- 
tended comment. The ordinary fishermen rarely distin- 
