184 STT.FAMILY x. CT-RCULIONIN.E. 



produced towards the sides; ventral segments of abdomen un- 

 equal, the first, second and fifth longer; front coxa? contiguous; 

 legs stout, the tibia* compressed, armed with a strong tooth at 

 tip, the articular surface on the side; terminal edge of hind tibia* 

 double, the corbel or space which they enclose, narrow except in 

 PacJii/loliius, where it is very large and wide; third joint of tarsi 

 dilated, spongy beneath ; claws simple, diverging. 



The members of the tribe are known as "bark weevils" and 

 they and their larvae do much damage to pine, fir, spruce and 

 other coniferous trees. The eggs are deposited by the female in 

 cavities excavated by the beak in the inner bark of the host tree. 

 The larva?, which are elongate, cylindrical, yellowish-white foot- 

 less grubs, infest both living and partly dead trees, deriving their 

 food from the inner bark, eating as they move slowly forward. 

 In this way they form long winding galleries in the inner bark, 

 and oftentimes grooves in the outer wood, these galleries or 

 grooves ending in cells in which pupation takes place. The adults 

 of some species emerge from the bark and hibernate in the ground, 

 while others pass the winter in the bark. 



KEY TO GENERA OF HYLOBIIXI. 



a. Mesosternum very short, depressed, only the process lying in the 

 same plane as the metasternum; thorax longer than wide, not nar- 

 rower than elytra; femora toothed. I. PARAPLIXTHUS. 

 aa Mesosternum moderately long; thorax usually wider than long, 

 ft. Tibiae short and thick, their outer apical angle dilated. 



II. PACHYLOIM is. 



6&. Tibiae of usual form, their outer apical angle not dilated. 

 c. Femora club-shaped, strongly toothed. 



(7. Body with spots of fine pubescence; tibiae not narrowed toward 

 the tips. III. HYLOISM s. 



dd. Body with spots composed of small scales; tibiae narrowed to- 

 ward the tips. IV. HEILIIM s. 

 cc. Femora feebly club-shaped, not toothed. 



e. Elytra oval, convex; eyes small. V. HYPOMOLYX. 



ee. Elytra elongate, parallel; eyes large. VI. En>oci:urs. 



I. PARAPLIXTIIT-S Faust, 1S!> (Or., "near" -)- Plinthns. i 



Beak as long as thorax, rather slender, distinctly curved; an- 

 tenna 1 inserted at apical fourth; first and second joints of funicle 

 subequal, each, one-half longer than those which follow; proster- 

 num slightly emarginate in front; first and second ventral seg- 

 ments each as long as third and fourth united, their suture deep 

 on the sides, obsolete at middle, their centers broadly excavate in 

 male; femora feebly clavate; tibia' rather long, curved near apex. 

 Our single species does not agree with the generic characters of 



