159 



which, according to my studies, makes uearly all its food from insects 

 (98 per cent.) found under stones in running water. Next are the Pirate 

 Perch, Aphredoderus (9L per cent.), and the Darters (87 per cent.), the 

 Croppies (73 per ceut.), halfgrown Sheepshead (71 per cent.), the 

 Shovel Fish (59 per cent.), the Chub Minnow (50 per cent.), the Black 

 Warrior Sunfish (CJuenobryttus) and the Brook Silversides (each 54 

 per cent.), and Eock Bass and the Cyprinoid genus N'oiropis (each 52 

 per cent.). 



" Those which take few insects or none are mostly the Mud-feeders 

 and the Ichthyophagous species, Ainia (the Dog-fish) being the only 

 exception noted to this general statement. Thus we find insects wholly 

 or nearly absent from the adult dietary of the Burbot, the Pike, the 

 Gar, the Black Bass, the Wall-eyed Pike, and the great river Catfish, 

 and from that of the Hickory Shad^ and the Mud-eating Minnows (the 

 Shiner, the Fat-head,^ etc.). It is to be noted, however, that the larger 

 fishes all go through an insectivorous stage, whether their food when 

 adult be almost wholly other fishes, as with the Gar and the Pike, or 

 mollusks, as with the Sheepshead. The Mud-feeders, however, seem 

 not to pass through this stage, but to adopt the limophagous habit as 

 soon as they cease to depend upon Entomostraca. 



"Terrestrial insects, dropping into the water accidentally- or swept in 

 by rains, are evidently diligently sought and largely depended ui^on by 

 several species, such as the Pirate Perch, the Brook Minnow, the Top 

 Minnows or Killifishes (Cyprinodonts), the Toothed Herring, and sev- 

 eral Cyprinoids {Sem^otilus, PimepliaJes, and Notropis). 



"Among aquatic insects, minute slender dipterous larvte, belonging 

 mostly to Chirononms, Corethra, and allied genera, are of remarkable 

 importance, making, in fact, nearly one-tenth of the food of all the fishes 

 studied. They are most abundant in Phenacobius and Utheostoma, 

 which genera have become especially adapted to the search for these 

 insect forms in shallow rocky streams. Next I found them most gen- 

 erally in the Pirate Perch, the Brook Silversides, and the Stickleback, 

 in which they averaged 45 per cent. They amounted to about one-third 

 the food of fishes as large and important as the Eedhorse and the River 

 Carp, and made nearly one-fourth that of fifty-one Buffalo fishes. They 

 appear further in considerable quantity in the food of a number of the 

 Minnow family {Notrojns, Pimephales, etc.), which habitually frequent 

 the swift water of stony streams, but were curiously deficient in the 

 small collection of Miller's Thumbs (Cottidce), which hunt for food in 

 similar situations. The Sunfishes eat but few of this important group, 

 the average of the family being only 6 per cent. 



" Larvte of aquatic beetles, notwithstanding the abundance of some 

 of the forms, occurred in only insignificant ratios, but were taken by 

 fifty six specimens, belonging to nineteen of the species, more fre- 

 quently by the Sunfishes than by any other group. The kinds most 

 ' Dorosoma. ^Pimephales. 



