GREAT WATER-BEETLE. 



241 



peculiar kind of contortion, was again withdrawn 

 The larger caddis- worm then put itself into motion ; 

 and to my surprise, I found that the lesser one was 

 attached by a silken cable to his more bulky com- 

 panion, and towed after him as a jolly-boat would be 

 towed by a cutter, without the means of offering any 

 resistance to its progress. 



If you are attending to the proceedings of the 

 caddis- worms in their natural habitats, you cannot 

 fail to observe the rapid plunging movements of the 

 great water-beetle (JDyticus marginalis) . The male 

 is easily distinguished from the female, by the 

 curious hemispherical appendages on the anterior 

 legs, which, acting Uke suckers, enable him to retain 



A, Larva — b, the perfect Di/ticus marginalis. 



a hold of his mate in the unstable element they in- 

 habit. Though living in the water, he is, at times, 



K 



