54 2 THE STUD Y OF INSECTS. 



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- 

 Fig. 651. spicuous, interrupted, reddish bands across the 

 wing-covers. 



The family TROGOSITID^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 MONOTOMID^E (Mon-o-tom'i-dae) 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-dae) 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 DERODONTID^E (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 BYRRHID^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 



