146 
NATURAL HISTORY OR 
this receptacle they are left to swim about till they 
are hatched. 
BRACHELYTRA. 
The insects belonging to the second great family 
of the Coleoptera wdth five joints in each foot, form 
a well-defined group, readily distinguishable from 
their associates by their peculiar aspect. The body 
is narrow" and elongated, and in its general form 
bears considerable resemblance to that of the Ear- 
wig. The elytra are so short that they seldom 
cover more than the base of the abdomen ; a cha- 
racter which has caused the family to be distinguished 
by the name Brachelytra.* This peculiarity in 
the form of the wing-cases is obviously designed to 
render the body more flexible, by removing every 
obstacle to the motions of the abdomen. That part ac- 
cordingly possesses a great degree of suppleness, and 
is capable of being inflected in almost every direc- 
tion. When the animal is alarmed, or repelling the 
attack of an assailant, it bends the abdomen forwards 
over its back, and protrudes two conical vesicles 
from the extremity, which in certain species emit a 
strong scent of sulphuric ether. While in this at- 
titude, the jaws are usually kept extended to their 
utmost stretch, by which the appearance of the 
larger kinds is rendered sufficiently formidable to 
* From shorty and iXvr^ov, a wing-case. 
