﻿10 



BRITISH BEETLES. 



with a horny front and head, the 

 latter having strong jaws, rudi- 



,/' mentary eyes, antennae, and palpi ; 



y they have mostly six hard front 

 legs, and appendages on the upper 

 side, with a fleshy tubercle on the 

 under side, of the last segment. 

 The legs are sometimes wanting 

 entirely, or replaced by fleshy tu- 

 bercles. The body is composed of 

 the head, and, usually, twelve seg- 

 ments, to the first three of Avhich 

 the horny legs are attached, one 

 on each side ; and there is usually 

 a spiracle, or breathing-hole, on 

 each side of all the segments, ex- 

 . ,. cept the second, third, and last, 



tiscus maTijinailS, a com- ^ ' ' 



mon Water Beetle (wai.s/rc). The number of tllCSC SCgmCUtS is 



" ^"oiTeof t'heeyes™""^ reduced in the perfect insect, as 



some of them are incorporated in 



the generative organs, etc. In some larvae, also, only 



eleven segments appear, owing to the non-development 



of the apical one ; e. ff. in Dytiscus mar- 



ginaVis the twelfth segment is formed into 



two mere appendages. I have remarked, 



moreover, in this larva, that the lateral 



spiracles (which are not fully developed, 



owing to respiration taking place at the 



tail) are abnormally placed, there being 



none on the first segment, two on the 



second, on the under surface of the body, 



^'S--- in front of the second pair of legs; none 



Pupa of Z). «?«)•- , , . 1 1-1 o ^ 



ginaiis (nat.size). ou the third. One ou cach Side or the 



Fig. 1. 

 Full- grown larva of D// 



