(X 300.) by a nervure and traversed by two A, With " bladder," b, longitudinal nervures, or the nervuration protruded; B, retracted, may be altogether degenerated.
Lameere's classification is founded on the number of abdominal sterna, the nervuration of the wings, the number of malpighian tubules (whether four or six) and other structural characters.
The details of the nervuration vary greatly in the different orders, but J.
The Mecaptera, with their predominantly longitudinal wing-nervuration, serve as a link between the Neuroptera and the Trichoptera, their retention of small cerci being an archaic character which stamps them as synthetic in type, but does not necessarily remove them from orders which agree with them in most points of structure but which have lost the cerci.
The order must therefore be ancient, and as no evidence is forthcoming as to the mode of reduction of the hind-wings, nor as to the stages by which the suctorial mouth-organs became specialized, it is difficult to trace the exact relationship of the group, but the presence of cerci and a degree of correspondence in the nervuration of the forewings suggest the Mecaptera as possible allies.
2, see Hexapoda, Aptera) in association with the tongue (hypopharynx); by the forewings when present being modified into short quadrangular elytra without nervuration, the complex hindwings (fig.