rniLIIYDRIDA. NECROPHAGA. 



125 



ting a strong odour, which is in some instances extremely fetid, 

 and which serves as a means of defence. 



706. The PIIILHYDRIDA possess antennae with a club-like 

 termination ; but these are usually shorter than one of the pairs 

 of palpi. Nearly all of them are aquatic, and have their legs 

 adapted for swimming, somewhat in the manner of those of the 

 Dyticus. The most remarkable genus is the Hydrous, of 

 which one .large species, an inch and a half long, oval, of a 

 brown-black colour, and highly polished, is common in the ponds 

 and ditches of this country. It swims and flies well, but walks 

 badly. The eggs are laid in a sort of cocoon, spun by the female, 



and coated with a gummy matter that is im- 

 pervious to the water on which it floats. The 

 larva?, which have a worm-like body, with six 

 feet, and with sharp mandibles arming the 

 head, are very voracious ; feeding upon Tad- 

 poles, the young fry in fish-ponds, and small 

 fresh-water Mollusca. The Sphceridia arid Cer- 

 cyons, which also belong to this group, are found 

 in the excrements of the larger mammalia, upon 

 which they and their Iarva3 feed. 



707. The succeeding tribe, that of the NECROPHAGA, consists 

 of those Pentamerous Beetles, whose antenna end in a club- 

 shaped enlargement, whose maxillary palpi are always consider- 

 ably shorter than the antennae, and whose limbs are not con- 

 tractile. They are all terrestrial. They feed for the most part 

 on animal matter, at least in the larva state ; but a large pro- 

 portion of them prefer substances which are 

 in a decaying or putrescent condition. One of 

 the most interesting genera is the Necrophorus 

 or Burying Beetle; so named from its habit 

 of excavating the ground beneath the dead bo- 

 dies of small quadrupeds, such as Mice or 

 Moles ; when they have interred the carcass, 

 they deposit their eggs in it, and the larvae, 

 when hatched, feed upon the flesh. Another 



genus, which includes a large number of species, is the Dermestes ; 



