46 



COLLECTING AND PRESERVING INSECTS. 



rated from those more powerful and bloodthirsty. The little 

 Entomostraca, or water fleas serve as food for the smaller 

 species. With care many species can be reared in this way, 

 and so little is known of their transformations that figures and 

 descriptions would be of great value. The interesting and 

 varied habits of the different families can also easily be noted. 

 The Ant-lions (Fig. 47) in the larva state (Fig. 48) dig pit- 



Fig-. 40. 



Ant-lion. 



falls in the sand. The adults may be preserved in the same 

 manner as Dragon flies. 



The May flies, or Ephemerids (Fig. 49), as their name implies, 

 are, when fully grown, very short-lived insects, the adult living 

 but a few hours. The body is slender and weak, being very 

 long ; the prothorax is of moderate 

 size ; the antenna? are subulate, awl- 

 like, being very small, as in the dragon 

 flics, while the parts of the mouth are 

 rudimentary, the insect taking no food 

 in the adult or imago state. The wings 

 are very unequal in size, the hinder pair 

 being much smaller, or in some instances 

 (Chloe and Ocenis) entirely aborted ; the 

 transverse veins are either few or numer- 

 ous ; the tarsi are four or five jointed, 

 and appended to the long, slender abdomen are two or three 

 long caudal filaments. 



The sexes unite while on the upper surface of the water, and 

 after a short union the female drops in the water her eggs "in 

 two long, cylindrical yellow masses, each consisting of numer- 

 ous minute eggs." Walsh states that he possesses a "sub- 

 imago of Palingenia bilineata, which oviposited in that state." 



May Fly. 



