210 



FEESH-WATER AQtTARIA. 



is also brown, but rather darker in the centre, and its wing- 

 cases have the appearance of having been scratched from 

 side to side. Its legs are brown. This insect is common, 

 and is frequently found in the company of C. striatus. 

 There are five other species belongiug to this genus, the 

 smallest of which is about iin. in length. The larv» of 

 aU these beetles are somewhat like those of Dytisci, but, 

 of course, smaller in proportion. 



The genus Il/ybius also possesses seven species, of which 

 I. ater (Fig. 135) is one of the largest, handsomest, and 

 most interesting. Its form is oblong-ovate and convex. Its 



Fig. 135. ILYBIUS ATER (MALE AND FEMALE). 



colour above is black (whence the specific name) with a 

 bronze tinge, and there are upon the elytra two brownish- 

 yellow streaks. The under-part of the insect's body is 

 brownish-black. This beetle is found in many parts of Britain 

 — e.g., around London, in Kent and Norfolk, and in Scotland. 

 I. fuliginosus has somewhat the appearance of a small Dytiscus 

 marginalis, and is found in many parts of Britain. It is 

 about ^in. in length, rather handsome, and looks well in 

 the aquarium. 



There are oidy three species of the genus Hydatieus found 



in Britain, all of which are oblong-ovate in shape and about 



^|ia. in length. The males, like those of the Dytisci and 



