INFLUENCE OF ENVIRONxMENT 



257 



Fig. lxxxiii. top left: A whirligig beetle (1), and its larva (2), natural size. 

 TOP center: a diving beetle, Dytiscus marginalis. A, larva, or water tiger 

 devouring an agrion larva; b, pupa; c, male beetle, top right: A Water- 

 scorpion, Ranatra fusca. center: A water-boatman, Notonecta species, bot- 

 tom : A Water-strider, Rheumatobates rileyi, female. 



