COLEOPTEBOTJS INSECTS. 
153 
which account they have received the above name. 
Many of these insects are distinguished by a pecu- 
liar conformation of the middle portion of the breast, 
which lies between the two anterior legs, and is pro- 
perly called the prosternum . It is defined on each 
side by a longitudinal groove, which sometimes re- 
ceives the antennae ; the anterior part is dilated and 
advanced close upon the mouth, while the opposite 
extremity is prolonged into a point which is ad- 
mitted into a cavity placed in the hinder part 
of the breast, a little before the insertion of the 
middle pair of legs. Such as exhibit a structure of 
this kind constitute the section Sternoxes , a term 
which bears reference to the acute process of the 
breast just alluded to. In other instances the pro- 
sternum is not dilated below the head, and scarcely 
ever produced into a spine behind ; and the body, 
instead of being firm and rigid, as in the species of 
the former section, is usually of a soft and flexible 
consistence. The latter circumstance has suggest- 
ed the name of Malacodermes for this section, a 
term composed of two Greek words signifying a 
soft skin . Both of these sections comprehend in- 
sects of considerable interest, both for their beauty 
and singular economy, and which require therefore 
to have some space devoted to their history. 
The Sternoxes are divisible into two well-marked 
families, corresponding to the genera Buprestis and 
Elater of Linnaeus. The Buprestidae are most rea- 
dily distinguished by not having the posterior angles 
