90 
The Food of the Smaller Fresh - Water Fishes. 
Summary for the Group. 
Ninety-five specimens of Group IV examined, representing 
five genera, had derived about three-fourths of their food from the 
animal kingdom, three per cent, of it being fishes, sixty-one per 
cent, insects, one per cent. Arachnida, and eleven per cent. Crusta- 
cea. One-third of the insects and spiders belong to terrestrial 
species. Chironomus larvae are among the most important aquatic 
elements, amounting to sixteen per cent.; neuropterous larvae 
coming next (eleven per cent.). About two-thirds of the crusta- 
ceans were craAvfishes, the remainder being Cladocera and Copep- 
oda. The vegetation (nearly one-fourth of the entire food) was 
chiefly of miscellaneous origin, nine per cent, only being recog- 
nizable as of aquatic forms. This was almost entirely filamentous 
Algae. 
Concerning this fourth group it may consequently be said, 
roughly, that the food consists of insects, crustaceans, and vegeta- 
ble debris, about two-thirds of it the first, one-fourth of it the last, 
and one tenth, the other. 
Summary for the Family. 
If we regard the two hundred and fourteen specimens of 
fourteen genera which I have studied, as fairly representative of 
the family Cyprinidae, and strike a separate balance of their food, 
we shall find that about thirty per cent, of the contents of the 
alimentary canal consists of mud; that one-half of it, or a little less, 
is animal matter, and that vegetation amounts to about one-fourth. 
Insects make one-third of the entire food, about ten per cent, 
being terrestrial species, eight per cent. Chironomus larvm, and an 
equal number larvae of Neuroptera. Of aquatic Coleoptera we 
have only a trace, and of aquatic Hemiptera (Corixa) but one per 
cent. Crustacea stand at ten per cent., nearly half of them 
Cladocera, Entomostraca as a whole amounting to about three- 
fourths of the crustacean ratio. Fishes are only two per cent., and 
mollusks less than one. Nearly half the vegetable food consists 
of Algfe (chiefly filamentous forms), the remainder being miscella- 
neous structures, derived from a great variety of plants, mostly 
terrestrial. 
