386 THE RHYNCHOTA. 



suborders is founded. In both these groups, how- 

 ever, the metamorphosis is imperfect (as in the Or- 

 thoptera), that is to say, the young escapes from 

 the egg in a form more or less closely approaching 

 that which it is ultimately destined to assume, and in 

 many cases the principal distinction between the larva 

 and the perfect insect consists in the possession of 

 wings by the latter. These organs make their ap- 

 pearance, as in the Orthoptera, towards the end of 

 the larval period of existence, in the form of thick 

 lobes upon the sides of the thorax, extending down 

 over the base of the abdomen. In those species which 

 never acquire wings, we may generally determine 

 whether the specimen before us is in the perfect 

 state or not, by the presence or absence of ocelli, as 

 those organs do not make their appearance in the 

 preparatory stages. 



Suborder HETEROPTERA. 



I have already stated that the most striking dis- 

 tinction between the two primary groups into which 

 these insects are divided, is to be found in the structure 

 of the wings. In the first suborder, the wings of the 

 anterior pair consist of two distinct parts, separated by 

 a sharp line, the basal portion being of a more or less 

 leathery or horny texture, whilst the apical portion 

 is membranous. These organs, consequently, combine 

 the characters of elytra with those of membranous 

 wings, and they have therefore been called hemelytra, 

 as they not only serve, like the elytra of the Beetles, 

 for the protection of the large delicate membranous 

 wings which are folded up beneath them in repose, 

 but are also employed as organs of flight. It is to 

 this dissimilarity in the texture of the fore- wings that 



