26 BRITISH BEETLES. 



tions the upper, or mesonotum, and lower, or mesoster- 

 num. In Fig. 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 

 ff l is the base, g^ the apex, g 3 the lateral margin, cf 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 prosier- 

 num, viz. (8, A), a, sternum; b b, episterna ; and c c, 

 epimera (the two last being the thin side-pieces of B in 

 Fig. 8) ; d is the coxa } and e the trochanter of one of the 

 legs. 



The metathorax, likewise divided into upper (metano- 

 tum) and lower (metasternum] surfaces, carries the wings 

 and hinder legs. 



Fig. 9. Metanotum of thorax of D. marginalis. 



The metanotum (Fig. 9) is composed of the usual four 

 dorsal pieces, and bears one of the wings on each side 



