ENTOMOLOGY. 
109 
as of two divisions,, which may he distinguished as 
the anterior and posterior wings of the scapulae.* 
The spiracle of the mesothoracic segment, which 
had been long overlooked, owing to its latent posi- 
tion, is found beneath and a little beyond the poste- 
rior wings. The patagia and tegulce of the Lepidop- 
tera and Hymenoptera, (which we shall afterwards 
allude to, when considering these orders) are attached, 
the latter to the mesonotum, the former to the poste- 
rior wing of the scapula. 
The mesosternum forms the under side of the 
mesothoracic case, being directly opposite to the 
mesonotum. It is in all cases distinct, and some- 
times comprehends a considerable area, in which the 
sockets of the middle legs are included. 
The only primary segment of the thorax remaining 
to be considered, is the Metathorax which, like that 
last described, supports a pair of legs and a pair of 
wings. It docs not attain a high degree of develop- 
ment in any of the orders, except among the Coleop- 
tera and 0) tboptera ,* its structure, consequently, can 
be most satisfactorily investigated in these. It may 
likewise be regarded, according to the authority we 
have chiefly followed in describing the constituent 
parts of the thorax, as consisting of seven pieces, 
which bear considerable resemblance to those of the 
mesothorax. The dorsal portion is the metanotum , 
commonly quadrangular, with the front emarginate, 
and the anterior angles consequently advanced. The 
Burmeister’s Manual, p. 81. 
