COLEOPTEROUS INSECTS. 
119 
Such as exhibit a formation of this kind constitute 
the section Truncatipennes. Some of the species 
have attracted much attention in consequence of a 
very singular means they employ to repel the at- 
tacks of their assailants. The majority of carabide- 
ous insects secrete an acrid and caustic fluid, which, 
when irritated, they discharge with considerable 
force. But in the kinds alluded to (belonging 
chiefly to the genus Brachinus), the fluid is so vo- 
latile, that when it is propelled by the insect it im- 
mediately evaporates with a detonating sound, so 
that the discharge seems to consist of blue smoke, 
which is of a peculiarly disagreeable and penetrat- 
ing odour. These bombardiers, as they are named 
by the French, can fire a considerable number of 
volleys before their ammunition is exhausted. The 
largest kinds inhabit tropical and other warm coun- 
tries ; but a few extend pretty far to the north, there 
being several indigenous to France and the south 
of England. 
To the section with truncated elytra belongs also 
the genus Anthia (a name originally applied by 
Aristotle to a kind of fish), which, however, does 
not well exemplify the distinctive feature of this 
subdivision, as the elytra are sinuated rather than 
truncated at the extremity. It is known by having 
the terminal joint of the external palpi somewhat 
cylindrical and truncated, or in the shape of a re- 
versed cone ; by the want of a tooth in the notch 
of the mentum ; and by the elongate-ovate form of 
