6 4 NATURAL HISTORY OF AQUATIC INSECTS CH. 



FIG. 13. Larva of Hydrophilus 

 piceus, dorsal view. 



Museum (Vols. xvm xx). 

 The following account of 

 Hydrophilus is taken from 

 that source. 



4< A larva, three inches 

 long," says Lyonnet, " was 

 discovered in the middle 

 of August on the grass at 

 the foot of a tree. Its 

 body was soot-coloured, 

 flattened from above down- 

 wards, tapering behind and 

 ending in a blunt point. 

 The head was broad, black, 

 and polished. The tip of 

 the tail was provided with 

 two hooks of unknown use, 1 

 which possibly enclose the 

 two filaments which the 

 pupa bears in the same 

 place. From the sides pro- 

 jected short and stout 

 spines, directed obliquely 

 backwards. The legs were 

 short and appeared unfit 

 either for running or for 

 swimming with rapidity. 

 The head, armed with 



1 It is believed that these 

 tail appendages are accessory to 

 respiration, as in the Dytiscus- 

 larva. 



