558 EXTERNAL ANATOMY OF INSECTS. 
bably to prevent the dislocation of these organs, which 
seems to indicate that they are used more in flight than 
those of other beetles. The Blatte also, in the next Or- 
der, have a winglet attached to the anal area of the zeg- 
mina. ‘The frenum, as in the preceding Order, lies un- 
der the margin of the scutellum and dorsolum, but which 
here forms one uninterrupted transverse line; it is near- 
ly vertical, and is attached to the alula. ‘The structure 
is not very different in the other Orthoptera*, but the 
Jjrenum is surmounted or strengthened by one or two 
ridges ; in Mantis it runs from the scutellum in an an- 
gular or zigzag direction—but in all it is attached im- 
mediately to the tegmen. In the Heteropterous Hemi- 
ptera it is represented by the narrow bead adjacent to the 
scutellum on each side *, which dilates into a flat plate as 
it approaches the Hemelytrum, with the Anal Area of 
which it is connected. But the Homopterous section of 
the Order in question furnishes examples of the most re- 
markable structure of this countercheck, which proves 
that it is really, what its name imports, a bridle. If you 
examine the great lanthorn-fly (Zwdgora laternaria), or 
any species of Cicada, &c., you will find adjacent to the 
scutellum or parallel with it, on each side a flat plate; 
and from the angle of that part in the first case, and 
from one of its processes in the last, you will further per- 
ceive a ridge or nervure which runs along this plate, in 
one forming an angle, and in the other being nearly 
straight, to the base of the ¢egmen, where it becomes a 
marginal nervure to a membrane that is attached to the 
posterior part of the base of the Anal and Costal Areas; 
and that this marginal nervure, like a ¢rvachea, consists 
? Prats VIII. Fie. 12. /. > Ibid. Fic. 20. 7. 
