The Food of Yovnij Fishes. 81 



two per cent, of larvns and piipfe of Chironomus. A few 

 young Allorchestes and some Oorixas complete the brief 

 list. 



Several specimens of Amia under one inch in length, 

 whose anatomy I studied three years ago, I remember to 

 have had their intestines packed with Entomostraca. 



LEPID08TEIDJ5:. 



Here also I shall have to content myself with such hints 

 of the food of the young as are given by two or three spec- 

 imens, as the youngest are not yet common enough in our 

 collections to supply more material for a study of their 

 food. One of the two smallest gars examined, an inch and 

 a fourth in length, taken in June, near Peoria, had filled 

 itself with Scapholeberis mucronata, and the other had ta- 

 ken only a minute fish. A specimen two inches long and only 

 an eighth of an inch in depth, furnished a striking illus- 

 tration of the voracity of this terror of our streams, as its 

 stomach contained sixteen minute Oyprinoids. 



S u m mary . 



A sufficient recapitulation of the foregoing data is af- 

 forded by the appended table of the food of the diif'erent 

 genera. It may be worth while to say that all the mate- 

 rial upon which the foregoing statements rest, as well as 

 all that used in the preceding paper, has been carefully 

 preserved, and may be seen at any time by those inter- 

 ested, at the State Laboratory of Natural History. 



The general conclusion from these observations is the 

 supreme importance of Entomostraca and the minute 

 aquatic larvae of Diptera as food for nearly or quite all 

 of our fresh-water fishes, — a conclusion that gives these 

 trivial and neglected creatures, of whose very existence 

 the majority of the people are scarcely aware, a promi- 

 nent place among the most valuable animals of the state, 

 for without them all our waters would be virtually depop- 

 ulated. Other facts of eminent interest thus brought to 

 view are the magnitude and intensity of the competition 

 for food among the young of all orders of fishes, where a 

 stream is fully stocked, and the injurious character of 

 such a species as the shovel-fish, which feeds on Entomos- 



