222 FEBSH-WATBE AQTJAEIA. 



violet tinge. This rather common beetle is very suitable for 

 the aquarium. 



Of the five species comprehended in the genus Hydrobius, 

 S. fuscipes is, perhaps, the commonest and most suitable for 

 the tank. This elegant insect can be found upon the weeds 

 of ponds, ditches, and slow-running streams in many parts 

 of England. It is sometimes useful in the aquarium as a 



consumer of oonfervae. About 



^ ^^ June the female makes a cocoon 



~;;5wl, ^W^ ^°^ ^^^ eggs, and attaches it to 



'^ the under -side of floating leaves. 



This sac is somewhat similar in 

 substance and appearance to 

 that constructed by the Sydro- 

 FiG. Ml. HYDROBIUS FUSCIPES. pJ^il^^g piceus, but is without 



the hollow stem. H. fuscipes 

 (Pig. 141) is about ^in. in length, and is of a very glossy, 

 brownish-black colour. Its shape is oval, and its elytra, sides 

 of its head, and thorax, are deeply punctured. The clubbed 

 antennae are rather large and conspicuous for the size of the 

 insect, and the legs are of a reddish colour. 



The ten or twelve species belonging to the genus Helophorus 

 are found crawling upon the weeds, bottoms, and sides of 

 ponds and slow-running streams in many parts of Britain. 

 They are frequently found out of 

 the water, and often covered with _ --_-^ 



mud. H. grandis (Fig. 142) is the 



^ 



largest and one of the commonest "^ik,-- 

 of the Helophori. It is oblong in -^^ 

 shape, the thorax being somewhat 

 narrowed behind. The latter and Fig. 142. Helophorus 



the head have a metallic appear- 

 ance, and there are a few faint 



brown spots upon the yellowish-brown elytra. The legs, palpi, 

 and antennsB, are of a yellowish colour. This insect, which 

 measiu-es about :jin. in length, may be found in ponds and 

 sluggish streams in almost all parts of the British Islands, 

 and at any season of the year. 



