34 
BRITISH BEETLES. 
or middle pair of legs, is also divided into two portions 
— the upper, or mesonotum, and lower, or mesosternum. 
In Pig. 8, b is the mesonotum, seen from above, a being 
the scutellum referred to in descriptions. Strictly 
speaking, there is a scutellum to each of the three seg- 
ments of the thorax; but it is the scutellum of the 
mesonotum which is invariably meant by this word, 
when no other reference is made. The mesonotum is 
also seen sideways at /, in Fig. 8, a, with one of the 
elytra, of which g' is the base, g 1 the apex, g' the lateral 
margin, g l the suture, and g : ‘ the disc. On the other 
side is the alula, or winglet, h, which is attached to 
the body and the under side of the base of the wing- 
case : it is a thin membrane, exposed in flight, and 
either covering, or a continuation of, the mesothoracic 
spiracle. 
The mesosternum, to which the middle pair of legs 
is attached, is composed of similar pieces to the pro- 
sternum, viz. (8, a), a, sternum ; b b, episterna ; and c c, 
epimera (the two last being the thin side-pieces of B in 
Pig. 8); d is the coxa, and e tho trochanter of one of 
the legs. 
The metathorax, likewise divided into upper ( meta - 
notum) and lower ( metasternum ) surfaces, carries the 
wings and hinder legs. 
Pig. 9.— Metanotum of thorax of D. marginalia. 
The metanotum (Pig. 9) is composed of the usual 
