HALIPLIDiE. 



61 



[Family 5. HALIPLIDjE.] 



Antenna' inserted on the front, just inside the eyes, ten-jointed, not 

 pubescent ; clypeus extended on each side of the insertion (as in the 

 Cicindelidte) ; metasternum with the antecoxcd piece marked by a 

 sat urcd line extending from one side to the other ; anterior and middle 

 coxae, globular, posterior coooce fixed and covered with leivge plates 

 concealing the greater peirt of the abdomen; legs slender, adapted 

 for swimming. 



The Haliplidje are all small insects and their distribution is 

 mostly Palaearctic, although a few occur in Central and South 

 America, and also in Australia. No species has yet been recorded 

 from India. They are chiefly distinguished by the large plates 

 on the abdomen ; a parallel structure occurs in the Carabid genus 

 Omophron, as observed above, and for this reason some authors 

 have proposed to associate Omophron and Halijplus. 



The most remarkable point about the Haliplidje is their larvse, 

 which are furnished at the sides with longer or shorter processes. 

 In Haliplus fudvus each scutum is furnished with four large 

 stout spines which are double as long as the segment that bears 

 them, and point backwards toward the apex ; there are no cerci 

 and the anal appendage is very long and divided before the apex 

 into two setose processes ; according to Schiodte there are eight 

 pairs of abdominal spiracles. The larva of Cnemidotus is very 

 extraordinary, its whole body being furnished with very long 

 filamentous branchiae ; there are no spiracles and air is obtained 

 by means of tracheae traversing these filaments, which are fixed 

 not on the segment directly, but on long spinose processes such as 

 are found in H. fulvus. The Haliplidje are found in both stag- 

 nant and running water under moss or other water-plants or 

 among stones, and they appear to swim by alternate movements 

 of the hind legs. As we have before remarked the Haliplidje 

 have very little in common with the Dytiscid^e, with which they 

 have sometimes been classed ; they are really nearer the Carabid.i5 

 and are worse swimmers than some of the sub-aquatic Cur- 

 culionid.e. The weevil Eubrychius velatus, for instance, is a strong 

 swimmer, using both hind legs like a Dytiscid, and it will live 

 under water for an indefinite time. 



