EXTERNAL ANATOMY OF INSECTS. 613 



delaria, serrata, and Diadema, sufficiently exemplify this 

 remark, as do several Mates likewise a . 



We may observe here — that tegmina are more calcu- 

 lated for flight than elytra, both from their thinner sub- 

 stance, and from the angle that their Anal Area, and often 

 the Costal, forms with the rest of the tegmen ; a circum- 

 stance which, in wings, M. Chabrier thinks presents some 

 facilities in that kind of motion. 



hi. Hemelytra b . The next species of wing-covers, 

 which though varying in the substance of their base, ter- 

 minate in a part distinct from the three areas, consisting 

 in almost every case of mere membrane, peculiar to the 

 Heteropterous Hemiptera, are called hemelytra, or half- 

 elytra : — this term was also formerly employed, but cer- 

 tainly incorrectly, to denote tegmina. I shall consider 

 them with respect to such of the particulars noticed under 

 the former heads as apply to them, but without repeating 

 them formally. 



1. As totheir substance, they must be separately consider- 

 ed with regard to their base and apex. In various instances 

 the base, or part consisting of the three areas, is almost 

 corneous, as in Cydnus Morio and bicolor, bugs not uncom- 

 mon with us, and many others c ; in these cases it is lined 

 with a hypoderma like elytra ; and in maziy the points, 

 which are impressed upon it, also perforate the hemely- 

 trum, and seem to act as pores : but in Lygceus, Reduvius, 

 Capsus, Mir is, and the majority of the Heteropterous He- 

 miptera, the organs in question being soft and flexible, 



a Stoll Cigales t. If. 1. L x. /. 46. t. xxix. /. 170. U v. /. 22. t. iv. 

 /. 19. &c. b Plate X. Fig. 3. 



c la Latreille's whole genus Penlatoma, including several Fabrician 

 genera, the Hemelytra are more substantial than in the subsequent 

 tribes. 



