60 CLARENCE L. TURNER Vol. XXII, No. 2 



effect upon the food ; the diet of the young P. caprodes consists 

 of copepods and cladocera while E. flahellare and B. fusiformis 

 take, in addition to copepods and cladocera, midge and may fly 

 larvae and ostracods. 



{e) Different Habitats. 



Some of the darters are very limited in their habitats. 

 Although a few seem to occur almost anywhere that a fish 

 might be expected to live. Cottogaster copelandi, for example, 

 was taken only in Lake Erie; Etheostoma cceruletim was con- 

 fined entirely to swift streams, but Etheostoma flabellare, 

 Diplesion blennioides, Ammocrypta pellucida, Percina caprodes 

 and Boleosoma nigrum were found in both Lake Erie and the 

 streams of the state. P. caprodes and B. nigrum may be expected 

 in almost any body of water except in isolated pools. It is 

 obvious that the small animal life of a swift stream and of a 

 lake choked with vegetation must differ and fishes confined to 

 such habitats must also differ in their food habits. Such a 

 dift'erence is much less than might be expected, however. 



Percina caprodes, Etheostoma flabellare and Diplesion blen- 

 nioides occurring both in Lake Erie and in the streams of the 

 state afford data for a comparative study of the food of the 

 same species of fish in different habitats. Amphipods form an 

 important item of food in the lake specimens of both E. flabellare 

 and P. caprodes, but they do not occur in the food of stream 

 dwelling forms. Midge larvee and may fly larvas are found in 

 the food of both stream and lake specimens, but species dif- 

 ferences are common. The same is true of the molluscan diet. 

 Planorbis and Physa were the snails utilized as food in lake 

 specimens but the fiat gastropod, Ancylus, was the only snail 

 found in the food of stream darters. Some specimens of P. 

 caprodes were found which had taken as many as thirty of the 

 latter snail. 



FOOD AND DISTRIBUTION. 



With the exception of Boleichthys fusiformis, all the darters 

 mentioned in this paper seem to be rather generally distributed. 

 Boleichthys has been taken only in the northern part of the 

 state, but there is no peculiarity in the food which could account 

 for this geographical limitation. Locally, however, the char- 

 acter of the food probably determines the range and distribution 



