(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 extraordinary 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 somewhat 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 subsequently 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 resisting medium, and in those that prey on their fellows they undergo such a change as to be convertible into 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
