FLIGHT OF INSECTS. 



313 



In the Orlhoptera, (Fig. 159), the coverings of 

 the wings, or tegmina, instead of being of a liorny 

 texture, are soft and flexible, or semi-membranous. 

 The wings themselves, being broader than their 

 coverings, are, when not in use, folded longitudi- 

 nally, like a fan. 



In the new order of Rliipiplera of Latreille,* 

 which includes only two genera, the tegmina are 



160 



159 



162 



anomalous both in their situation and shape; being- 

 fixed at the base of the mesothorax, very long and 

 narrow, and apparently incapable of protecting 

 the wings. The wings themselves are of ample 

 extent; forming, when expanded, a quadrant of a 

 circle, with five or six nervures radiating from their 

 base, and folded longitudinally. 



In the Hemiptera, the tegmina, or as they are 

 here called, the hemi-clytra, are coriaceous towards 

 their base, but membranous towards their extre- 

 mity, and the true wings are folded transversely, 

 so as to cross one another. These hemi-elytra are 

 employed to strike the air in flight, and their move- 

 ments accompany those of the wings. 



* The Strepsiptera of Kirby. See Transactions of the Linnean 

 Society, XI. 86. 



