I 



WATER BEETLES. 265 



vegetation as well as on living plants; a few art 

 carnivorous, and these are more active. Thej 

 breathe by taking an air supply down into the water, 

 this is spread out like a beautiful silver film over 

 the under surface of the body. It gets the supply 

 of air by raising the antennae out of the water and 

 then drawing them down, thus an air bubble is 

 captured and sent over the lower surface of the 

 body. 



These beetles are somewhat similar to dytiscids, 

 but can be distinguished by the structure of the 

 antennae. They are short, but with the lens can be 

 seen to consist of three parts: (1) the base, of one 

 or more elongate joints; (2) the middle part, of a 

 number of small joints; (3) a terminal part, where 

 the joints are broader, forming a small club. The 

 legs are similar to those of the dytiscids or divers. 

 The back legs are longer and oar-like, the front pair 

 short and paddle-like. 



Habits. The motlier insect of many species forms 

 egg cocoons containing many eggs, which may be 

 fastened to water plants, or carried for some time 

 by the mother. These beetles, like other types, have 

 flying wings and move from one pond to another. 

 They are often captured when flying around liglits 

 at night. The larvae are predaceous even when the 

 adult feeds on plants. 



