286 Fresh Water Aquarium 



upper horny wing - covers having a sharply 

 defined dark yellow border. Folded up un- 

 der the covers are a pair of strong trans- 

 parent wings which enable the beetle to fly 

 great distances at a good speed. The body 



Fig. i 16. Yellow-bordered Water Eeetle, 

 Dytiscus marginalis, male. 



is light, convex and very hard and glossy 

 all over. The small head shows two big 

 black eyes. Of the six legs the hind pair is 

 strongly developed and furnished on the in- 

 side with a dense line of very stiff light 



