THE ORDER OF COLEOPTERA. 
38 
subsist chiefly upon the larvae of other insects, and are therefore useful 
in helping to maintain a proper balance of insect life. As their name 
implies, they are found mostly on the ground. They run with great ra- 
pidity, and never attempt to seek safety by feigning death, as is the 
habit with many of the leaf and fruit-eating beetles. 
The tribe contains two families, distinguished as follows : 
A. Head large and vertical, wider than the thorax ;* antennae inserted 
on the front; eyes large and prominent; mandibles strongly 
toothed ; wing covers usually marked with yellow : 
OlCINDELIDiE. 
A A. Head horizontal or a little inclined, usually narrower than the 
thorax; antennae inserted under the sides of the front; eyes 
moderate; mandibles simple or slightly toothed; color usually 
black; sometimes blue, green or brown; very rarely spotted : 
Carabidao. 
Family I. CICINDELirEE, (Tiger-beotles.) 
The Oicindelidoe are readily distinguished from all other pentamerous 
beetles, by their large vertical heads ; that is, their heads are so set 
rFig.5.) 
upon the thorax that when viewed from above, only 
the vertex or crown is distinctly seen, the face looking 
directly forwards. In a few large species which vary 
from the family type the head is not quite vertical, but 
yet strongly inclined downwards. 
The common English name of Tiger-beetles express- 
es very well the character of these insects, and they 
may be said to represent in the insect tribes the tiger 
amongst quadrupeds, and the hawk and eagle amongst 
ard’a Guide. birds. They are the most highly organized and per- 
fect of all coleopterous insects, and run and fly with equal facility. They 
are often seen running in hot dusty roads. W hen pursued they fly 
quickly, but usually alight again a rod or two in advance. About sev- 
enty species have been described as inhabiting the United btates, in- 
cluding those found on the Pacific side ol the continent. 
♦That part of the body of a beetle wliicli, when viewed from above, lies between the head and the 
base of the elytra, commonly called the thorax, is found upon dissection to ho only the anterior section 
or pro-thorax, which is here greatly developed; all of the meso-thorax, except the little triangular 
piece called the scutellmn, and the whole of the meta-thorax, being concoalod under the basal portion 
of the elytra Many recent writers have, therefore, adopted for this part the name at pro-thorax, which 
thus has (he advantage of greater anatomical precision. The term thorax, on the other hand, has the 
claim of brevity and of long established usage, aud this brief explanation will relieve it of any amhi- 
guity that might otherwise be attached to it. 
