CO LEO P TER A . 
S9S 
to tropical regions, and, except in the far South, only a single 
species occurs in this country. This species is the Northern 
Brenthid, Eupsalis nttnuta (Eu r psa-lis mi-nu ta), which is 
represented by Figure 726. In the female the head is pro¬ 
longed into a slender snout; but in the male 
the snout is broad and flat, and is armed with a 
pair of powerful jaws. These are weapons of 
offence, for the males fight desperately for their 
mates; and, too, the males are generally larger 
than the females—an unusual occurrence among FlG - ? 26 * 
insects. It is interesting, as has been pointed out by Mr. 
A. R. Wallace in his “Malay Archipelago,” “as bearing on 
the question of sexual selection, that in this case, as in the 
stag-beetles, where the males fight together, they should 
be not only better armed, but also much larger than the 
females.” 
The Northern Brenthid is found upon oak-trees, in the 
solid wood of which the larvae bore, and is widely distributed 
over the United States and Canada. 
One species of Brenthus is found in Southern Florida 
and two in Lower California. In this genus the snout is 
slender in both sexes. 
The only other representative of this family that occurs 
on this continent north of Mexico is the Sweet Potato Root- 
borer, Cylas formicarius (Cy'las for-mi-ca'ri-us), of Louisiana 
and Florida. This beetle is somewhat ant-like in form ; the 
color of the elytra, head, and snout is bluish black, that of 
the prothorax reddish brown. 
Family CALANDRIDiE (Ca-lan'dri-dae). 
The Bill-bugs . 
To this family belong some of our most common snout- 
beetles. Here the lateral edge of the metathorax and of 
the abdomen fits into a groove in the wing-cover, and the 
surface of the wing-cover in this groove has a pearly lustre; 
