of the mouth, will be sufficient to distinguish them. But it has been recently shown, that two minute appendages, attached to the sides of the mesothorax, may be regarded as representing anterior wings; these have been named pseudelytra, or prebalanciers. The structure of the other parts will be well understood from the dissections on Pl. XXXIII. which we have taken the liberty to copy from Mr. Curtis' Brit. Ent. as they are the most satisfactory that have come under our observation. The head (E) is broad and sessile, with a triangular projection in the centre; eyes lateral, globose, and formed of few large facets; antennæ, with more than one branch (F 1, and G); palpi (H) large and two-jointed. The prothorax and mesothorax (I and K) are very short, being narrower than the head; the mesothorax (D 6), on the contrary, is large and long, and produces a large scutellum (D*), which projects over the abdomen, the latter composed of 8 or 9 joints, and somewhat incurved at the extremity. In Stylops the anterior wings appear as represented at K 9. It is on account of their twisted appearance that the name Strepsiptera (from στρεψις and πτερον) has been applied. The hinder wings, or what may be regarded as the only wings, if we consider their function, are very ample, folded longitudinally like a fan, the nervures remarkably fine (L 10). The legs are short and compressed, without spines, the tarsi (which are four-jointed,) having each joint furnished with a pubescent membrane (K 8*), claws wanting.
Rossi was the first who observed one of these
