350 



THE MECHANICAL FUNCTIONS, 



broader than their coverings, are, when not in 

 use, folded longitudinally, like a fan. 



In the new Order of Rhipiptera 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 anterior legs, 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 longitu- 

 dinally. 



In the Hemiptera, the tegmina, or as they 

 are here called, the hemi-elytra, are coriaceous 

 towards their base, but membraneous towards 



* The Strepsiptera of Kirby. See Transactions of the Lin- 

 neean Society, XI. 86. 



