584 the study of insects. 
Fig. 712. 
the body and discharging an oily fluid from it. They present 
an absurd appearance, walking off clumsily, 
and carrying the hind end of the body as high 
as possible. The most common species are 
large, smooth, club-shaped beetles (Fig. 712), 
and are commonly known as Pinacate-bugs. 
These beetles and those belonging to several 
closely allied genera are wingless. 
The family Aigialitid./E (yE-gi-a-lit'i-dae) 
was founded upon a single species from Alaska; 
recently another has been found in California. 
The family CiSTELiDAS (Cis-tel'i-dae) in¬ 
cludes about fifty North American species, some of which 
are quite common. These are brownish beetles, without 
spots, which are found on leaves and flowers and under bark. 
The body is usually elongate, elliptical, and quite convex. 
They are most easily distinguished from allied families by 
the tarsal claws being pectinate, and the anterior coxal cavities 
closed behind. The larvae of some of our species at least live 
in rotten wood and resemble wire-worms in appearance. 
The family OTHNIID/E (Oth-ni'i-dae) is represented in our 
territory by four species of Othnius (Oth'ni-us), one from 
the East and three from the far West. They are small 
beetles, which are found running actively on the leaves of 
trees, and are probably predaceous. In this family the an¬ 
terior coxal cavities are closed behind, and none of the ab¬ 
dominal segments are grown together on the ventral side. 
The family LAGRUDiE (La-gri'i-dae) includes only five 
North American species, all of which are from the East, and 
are found under bark and on leaves. They are elongate 
beetles, with a narrow, subcylindrical prothorax, and 
a more or less brassy color. Our most common spe¬ 
cies is Arthromacra eenea (Ar-thro-ma'cra ae'ne-a). 
This species is nearly half an inch in length (Fig. 713). 
The family Monommid^e (Mo-nom'mi-dae) is rep- Fig ‘ 7X3, 
resented in this country by a single genus, including four 
