SCOLYTIDAE. 523 



are stronger, nearly flat above, and the labrum is obsolete; these 

 characters indicate a recurrence towards the normal Khyncho- 

 phora. The funicle of the antennae is 5-7 jointed; the first joint 

 stout, the others slender, closely united ; the club is very slightly 

 compressed, annulated, and pubescent, oval-pointed in Hylesinus, 

 circular, compressed, nearly glabrous, with transverse sutures in 

 Dendroctonus. The ventral segments are convex, nearly equal ; 

 the first and fifth somewhat longer, the sutures deep and straight. 

 The tibia) are dilated, and strongly toothed exce'pt in Cnesiuus 

 and Bothrosternus, where they are not serrate ; the third joint 

 of the tarsi is usually bilobed, and the fourth very small ; the fifth 

 long with divergent simple claws. 



The basal margin of the elytra is elevated and acute as in the 

 two preceding groups, and the prothorax is narrowed from the 

 base forwards. 



Funicle 7-jointed. 2. 



Funicle 5-joiiited. 4. 



Prosternum narrow, tibi;» serrate. Hylesiuus. 



2. Prosternum wide between the cox;e. 3. 



3. Front tibife with three small teeth ; prothorax strigose. Cnesinus. 

 Tibiae bidentate, front ones with a large apical bifid si:)ine ; prothorax 



densely jjunctured. Bothrosternus, 



4. Club oval, obtusely pointful ; first joint of tarsi not shorter ; outer joints 



of funicle much broadei'. Phloeosinus. 



Outer joints of funicle scarcely broader. ChaetophlcEUS. 



Club oval-elongate ; first joint of tarsi short. Carphoborus. 



Club circular, compressed ; first joint of tarsi not shorter. 



Dendroctonus. 



Cnesinus has priority over Nemophilus Chapuis. Hylesinus, 

 Fhlceosinus, and Dendroctonus extend across the continent; 

 Chsetophlceus is represented by one Californiau species; the 

 others all belong to the Atlantic region. 



Group IV. — Crypttirgi. 



This group consists of two genera, represented by very small 

 species of elongate form, which agree with Hylastes in general 

 appearance and sculpture, but differ by the beak being much 

 shorter, and the i)rosternum very short and not excavated. The 

 genus Crypturgus has been usually associat(!d with the Tomicini, 

 on account of the slender tarsi, but it makes a notable exception 

 to the other meml)ers of that tribe by the large exserted head, and 



