The Food of Fishes. 41 



nias. The fourth, one and seven-eighths inches long, 

 caught at Peoria, in October, had eaten only larvae and 

 pui)ce of Chironomus. 



The two adult specimens were feeding chiefly upon the 

 larvae of Neuroptera — especially May-flies. An Allor- 

 ehestes dentata and a few small grasshoppers also appeared 

 in the food. 



It will be seen that this species apparently agrees closely 

 with the preceding in its food. The large amount of crus- 

 tacean food in the smallest specimen shows that we shovild 

 probably find still smaller Labracidae depending upon these 

 as strictly as the Percida?. 



Family CENTRARCHID^. The Sunfishes. 



This interesting group, known, in some of its members, 

 to every one who has ever seen a dozen fishes, is represented 

 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 im- 

 portant species. The rock bass, the croppie and the com- 

 mon sunfish {Leplopomus palUdus)^ 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 "pumi^kin-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 gen- 

 era, 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, Kaf. Large-mouthed Black Bass. 



This famous species is too well known to require extended 

 comment. The ordinary fishermen rarely distinguish it 



