THE 



AMERICAN NATURALIST. 



Vol. xvi. — JULY, 1882. — No. 7. 



ON SOME ENTOMOSTRACA OF LAKE MICHIGAN 

 AND ADJACENT WATERS. 



ANE cannot go far in the study of the system of organic life 

 ^ which prevails in a stream or lake, without being made aware 

 of the important part played therein by the neglected but inter- 

 esting group of the smaller crustaceans. They occupy a central 

 position not only in the classification of aquatic animals, but also 

 in the complicated network of physiological relations by which 

 the living forms of a body of water are held together as an 

 organized society. Feeding, themselves, upon the lowest and 

 smallest of plants and animals, they furnish food in turn to a great 

 variety of the higher animals, and even to some plants. 1 



The fisherman who toils at his nets, the sportsman in pursuit 

 of health and recreation, rarely reflect, even if they know, that 

 their amusements and their labors depend strictly upon these 

 humble creatures, of whose very existence, indeed, many of them 

 are unaware ; and yet there is ample evidence that, with few and 

 unimportant exceptions, all young fishes, of our fresh waters at 

 'least, live for a time almost wholly upon entomostraca. 2 If de- 



Nea ly Ire fourths o 



