220 



A qua tic Organisms 



differs strikingly 



in being covered with an 

 filamentous gills which sur- 



case, 



abundance of forking 



round the body as with a whitish fringe. It feeds, often 



in some numbers, on the under side of leaves of the white 



water-lily, or about the sheathing leaf bases of the 



broad-leaved pond weeds (Potamogeton) . 



ElophiJa fulicalis lives on the exposed surfaces of 

 stones in running streams, dwelling under a silt-covered 

 canopy of thin-spun silk, about the edges of which it 



forages for algse growing on the 



l 6' 



stones. 



Its body is 



: I " i 7/1 , 

 Fig. 128. Larva of Elophila 



depressed, and its gills are unbranched and in a 

 double row along each side. It spins a dome-shaped 

 cover having perforate margins under which to pass 

 the pupal period. It emerges, to fly in companies of 

 dainty little moths by the streamside. 



All these aquatic caterpillars like their relatives on 

 land, are herbivorous. They are all small species; 

 they are of wide distribution and are often locally 

 abundant. 



Liu beeti ...put Colfubtcrm an- mainly terrestrial, 

 mere being but half a dozen of the eighty-odd families 

 of our fauna that are commonly found in the water. 

 Both adults and larvae are aquatic, but, unlike the bugs, 

 the beetles undergo extensive metamorphosis, and 



