542 
THE STUD Y OF INSECTS . 
Fig. 651. 
abdomen exposed; but sometimes the elytra are entire. 
The tarsi are usually five-jointed, with the fourth segment 
very small; they are more or less dilated ; the posterior 
coxae are flat, not sulcate ; the anterior coxae are transverse ; 
and the abdomen has five free, ventral segments. 
One of the most common representatives of 
this family is Ips fasciatus (Ips fas-ci-a'tus). (Fig. 
651.) It is a shining black species, with two con¬ 
spicuous, interrupted, reddish bands across the 
wing-covers. 
The family Tr0G0SITID,E (Trog-o-sit'i-dae) includes ob¬ 
long, somewhat flattened beetles, of a black or reddish-black 
color. Most of them live under bark; but some are found 
in granaries. They differ from members of the preceding 
family in having slender tarsi, with the first segment very 
short. 
The family MoNOTOMiDiE (Mon-o-tom'i-dse) is composed 
of a few small, depressed beetles, found mostly under the 
bark of trees. The wing-covers are truncate behind, leaving 
the last abdominal segment exposed. 
The family LATHRIDIID/E (Lath-ri-di'i-dse) includes very 
small beetles, which live under bark and stones and are 
sometimes caught flying in twilight. They are oblong; the 
wing-covers are usually wider than the prothorax and 
entirely cover the abdomen. 
The family DERODONTIDiE (Der-o-don'ti-dae) is repre¬ 
sented by a single species found in the East and two found 
in Oregon and northward. The eastern species is a small 
brown beetle with a tubercle on each side inside the eye. 
The family Byrriiid/E (Byr'rhi-dae) or the pill-beetles are 
short, very convex beetles of small or moderate size; some, 
however, are half an inch in length. The body is clothed 
with hairs or minute scales. The legs can be folded up very 
compactly, the tibia usually having a furrow for the recep¬ 
tion of the tarsus. These beetles are found upon walks and 
