214 



NATURAL HISTORY. 



red and black arranged in cross-bars across the body. Still, no matter 

 how prettily marked they may be, they are not attractive, for they usually 



■C^ '^V.'KC-i.^'^' 





Fig. 210. — Carrion-beetles (Necrophorus) engaged in burying a mouse. 



smell strongly of the carrion ; and, as if this were not enough, many species 

 have the power of secreting a fluid of most nauseous odor. 



There are several groups of water-beetles, most of them of value to 

 mankind from their habit of preying upon the larvae of other insects. 



Fig. 211. — Water-beetles (Hydrophihis) ; at the left a larva ; attached to the leaf is a case of eggs. 



Both the larvae and the adults may be found in almost every pool of water ; 

 the larvae are not able to leave the water, but the adults frequently fly ; and 



