EXTERNAL ANATOMY OF INSECTS. 621 
“= 
have already got a tolerably good idea of these areas from 
what has been said upon the subject under tegmina and 
hemelytra ; but I shall now more particularly state to you 
how they are circumstanced in wings. I shail first ex- 
plain the general law as to their limits. The Costal 
Area* is all that longitudinal portion of the wing that 
lies between the anterior margin and the postcostal ner- 
vure; the intermediate Area” is all that longitudinal 
portion of the wing that lies between the postcostal and 
the anal nervures: and the Anal Area < is all that longi- 
tudinal portion of the wing that lies between the anal 
nervure and the posterior margin. But there are other 
helps to enable you to distinguish the areas in the dif- 
ferent Orders. The Anal Area in all Orders forms the 
posterior fold of the wing; in Coleoptera turned under 
when in repose; in Orthoptera folded like a fan; in 
Lepidoptera, in some Papilionide, forming an arch 
over the abdomen. Again, in Blatta, the Costal Area 
is distinguished chiefly by Jongitudinal nervures; the 
Intermediate by oblique ones; and the Anal by ra- 
diating ones; and in both this tribe and the Mantide 
those of Hymenoptera were stated to consist of three portions, viz. 
Basis, Medium, Apex (i. 211.) ; which mode of dividing them was at 
first adopted by M. Latreille. (Gen. Crust. et Ins. iti. 226. Note 1.) 
The same learned author (Ibid. iv. 239.), with regard to the Diptera, 
made a near approximation to the plan of dividing wings into longi- 
tudinal areas, but by the addition of a dasal area, which interrupts 
the attenticn to the communication of the areas with their aves, he 
has rendered his system less perfect. Two of his terms—Costal Area 
and Intermediate Area, are here adopted ; but his Internal is changed 
to the Anal Area, for the term internal belongs rather to the base of 
the wing. M. Latreille afterwards relinquished both these plans, 
N. Dict. d Hist. Nat. i. 248—. 
® Prats X. and XXVIII. &-. @. is the Postcostal Nervure. 
> Ibid. c. n’. is the Anal Nervure. © Ibid. d’. 
