618 EXTERNAL ANATOMY OF INSECTS. 
of the Anal Area are received by a ligament attached to 
a transverse plate, widest at its anterior end, which con- 
nects with the posterior part of the said humerus; and 
at its posterior end is united to the postfrenum*, with 
which it forms a right angle. In the Orthoptera Order 
the structure is not very different, but the axes and other 
plates of the base of the wing are less distinct and rather 
cartilaginous ; the nervures of the Anal Area often ter- 
minate in a transverse one that there forms the segment 
of a circle® ; the inner base of this circle is ligament con- 
nected with the postfranum. In the Homopterous Hemi- 
ptera the three axes may be readily traced, but the humeral 
plate, with which they all are connected, is more irre- 
gular in shape, and in Fudgora longitudinal, with an an- 
gular surface; in this Order the nervure, in some cases 
consisting of cartilaginous rings*, in which the frenum 
and posi/renum terminate in the tegmina and wings, is 
attached posteriorly to the ligament of the Anal Area. 
Inthe Heteropterous section the three axes are evident, 
but the humeral plate is not easily made out. In the 
Libellulina the axes of the Costal and Intermediate Areas 
are the coloured broad plates at their base, formed by 
thedilatation of their nervures; that, however, of the Anal 
is not dilated, but forms one nervure, in the primary 
wing, with the frenum, and in the secondary with the 
postfrenum. Waving given you this clue to trace the 
axes in those tribes in which they are most conspicuous, 
it will assist you in searching for them in the remaining 
Orders, in all of which they may be traced, except per- 
* See above, p. 570—. 
> Prats XXVIII. Fie. 9. a. 
* See above p, 558—. and Prarz XXVIII. Fic. 11. a. 
