appears as a triangular piece interposed between the wings at their base; it is very conspicuous in most beetles, and, in the heteropterous section of the hemiptera, it is sometimes so large (as in Tetyra, Fab.) as to cover the whole abdomen, having both the hemelytra and the wings beneath it. In certain cases there is no indication of the scutellum on the surface, in consequence of it being covered by the elytra and pronotum, but it is always present, although the insects in question (Copris may be given as an example,) have been called exscutellati, or destitute of a scutellum. A strong membrane or process may be frequently observed connecting the scutellum with the elytra or upper wings, and acting as a kind of counter-check to the latter during flight. This is best seen in the great lanthorn-fly, (Fulgora lanternaria,) where there is a flat plate on each side of the scutellum, with a ridge or nervure running along it to the base of the tegmina, which nervure consists of a number of cartilaginous rings, and thereby admits of tension and relaxation, as the tegmina rise and fall. The part in question has been named the frenum or bridle.
The scapulæ constitute the second principal portion of the mesothorax. They lie close upon the mesonotum, one on each side in front, assisting to form the articulating socket of the superior wings; they then contract themselves, in order to pass into the cavities of the prothorax, and, with their opposite wing, they pass down the sides of the second thoracic segment. They admit, therefore, of being regarded
