108 
INTRODUCTION TO 
appears as a triangular piece interposed between 
the wings at their base; it is very conspicuous in 
most beetles, and, in the heteropterous section of the 
hemiptera, it is sometimes so large (as in Tetyra , Fab.) 
as to cover the whole abdomen, having both the 
hemelytra and the wings beneath it. In certain 
cases there is no indication of the scutellum on the 
surface, in consequence of it being covered by the 
elytra and pronotum, but it is always present, al- 
though the insects in question (Copris may be given 
as an example,) have been called exscuteUati , or des- 
titute of a scutellum. A strong membrane or process 
may be frequently observed connecting the scutellum 
with the elytra or upper wings, and acting as a kind 
of counter-check to the latter during flight. This 
is best seen in the great lan thorn-fly, ( Fulgora 
lanternaria,') where there is a flat plate on each side 
of the scutellum, with a ridge or nervurc running 
along it to the base of the tegmina, which nervure 
consists of a number of cartilaginous rings, and thereby 
admits of tension and relaxation, as the tegmina 
rise and fall. The part in question has been named 
the frenum or bridle. 
The scapidce constitute the second principal por- 
tion of the mesothorax. They lie close upon the rae- 
sonotum, one on each side in front, assisting to form 
the articulating socket of the superior wings ; they 
then contract themselves, in order to pass into the 
cavities of the prothorax, and, with their opposite 
wing, they pass down the sides of the second thoracic 
segment. They admit, therefore, of being regarded 
