HEMIPTERA. 267 



(Ledra aurita,) and, from the curious aspect they 

 give to the Centroti, these insects are called in France 

 petits diables and demi-diables. It is the prothorax 

 that forms the large foliaceous expansion covering 

 the whole upper surface of the Membraces, an ex- 

 traordinary structure to which we are unable to assign 

 any use, and which, as has been remarked, seems 

 created by nature only for the purpose of shewing her 

 inexhaustible fecundity in varying animal forms. 



The metathorax is sometimes of considerable size 

 in the Heteroptera. The scutellum is often so large 

 as to form a very marked feature in 'the appearance 

 of these insects, covering the whole of the surface of 

 the abdomen, and protecting the wings like an elytron. 

 On the other hand, it is minute in Cicada and the 

 allied genera, and difficult to determine, presenting 

 at times the form of a St. Andrew's cross, and some- 

 what forked posteriorly. In Fulgora it is triangular, 

 while in Centrotus, Membracis, and some other genera, 

 it is linear and transverse. 



The legs present numerous variations in different 

 species, as will appear from the descriptions subse- 

 quently given. These variations in the locomotive 

 organs are rendered necessary by their diversified 

 habits and modes of life. In such as inhabit waters 

 they become adapted to oar the body through a resist- 

 ing medium, and in those that prey on their fellow? 

 they undergo such a change as to be convertible intf 

 instruments of prehension. Even in those cases where 

 they are entirely terrestrial and apparently of similar 

 habits, the legs frequently differ both in their relative 



