The Food of Fishes. 61 



addition of considerable quantities of terrestrial and 

 a([uatic insects. 



The gill-rakers of this species are numerous, long and 

 slender, — a fact reflected in the food. Fifteen per cent, 

 of the contents of the stomach of the largest specimen con- 

 sisted of Cyclops and five per cent, of Chironomus larvae. 

 Consistently with the small mouth and pointed pharyngeal 

 teeth, no traces of fishes or mollusks were found in the 

 food. 



POMOXYS NIGROMACULATUS, LaC. BlACK CrOPPIE. LaKE 



Croppie. Silver Bass. Butter Bass. 



PoMOXYS annularis, Raf. White Croppie. Timber Crop- 

 pie. Silver Bass. 



These two species, often not distinguished even })y ex- 

 perienced fishermen, agree so closely in food that I have 

 not thought it worth while to treat them separately. In 

 the Illinois and Mississippi rivers they are much the most 

 valuable and important of the family, excepting the black 

 bass. They are nowhere else so abundant in the state, 

 although occurring in the larger rivers generally and in 

 the Great Lakes. Tlie first species is commonest to the 

 north, and the second southward, so far as my observation 

 goes. In the Illinois, they are about equally abundant. 

 These fishes are everywhere great favorites, and rank 

 among the most important and promising of our smaller 

 species. They are rarely found in creeks or small ponds, 

 but seem to require deeper water for their maintenance. 



The gill-rakers of this species are numerous, long, and 

 finely toothed, constituting the most efficient straining ap- 

 paratus to be found among the sunfishes. The pharyngeal 

 teeth are sharp, and the mouth is rather wide and consid- 

 erably enlarged by the lengthening of the lower jaw. 



Consistently with the hypothesis concerning the mean- 

 ing of the gill-rakers which I had already formed from a 

 study of the preceding species, before I came to this, I 

 found that the young continued to feed almost exclusively 

 upon Entomostraca much longer than the other sunfishes. 

 Six specimens between three and four inches long, had 

 eaten little else than Entomostraca and the larvae of mi- 



