LeConte.] 



SCOLYTID^. 341 



Beak thick, neither dilated at tip, nor cylin- 

 drical, slightly narrowed from the base 



to the tip, convex 2. 



Beak very short, parallel on the sides 4. 



" longer, gula only feebly concave trans- 

 versely PHLCEOPHAO-US. 



2. Club rounded, pubescent, feebly annulated 3. 

 Club corneous, truncate at tip, which is 



spongy; funicle 5-jointed WOLLASTONIA. 



3. Funicle 5 jointed AMAURORHINUS. 



" 6-jointed HEXARTHRUM. 



" 7-jointed ELASSOPTES. 



4. Tarsi dilated, antennal grooves long RHYNCOLUS. 



" narrow, antennal grooves very short. . STENOSCELIS. 



The genera and species are fully described by Dr. Horn in the memoir 

 above cited, and need no farther mention at present. 



Family IX. SCOLYTID^. 



Mentum moderate in size, varying in form in some genera according to 

 sex; without gular peduncle (except in Hylastes, where it is very small) ; 

 ligula and palpi small, the former sometimes retracted, sometimes promi- 

 nent. 



Maxillfe exposed, palpi stout and short. 



Mandibles stout, curved, more or less toothed on the inner side. 



Antennae inserted on the sides of the head, between the eyes and mandi- 

 bles ; composed mostly of scape and club, funicle usually very short, from 

 1- to 7-jointcd; club large, solid, annulated, or rarely (Phlceotribus) lamel- 

 lated; surface of the club more or less sensitive according to genus. 



Head prominent in some tribes, detiexed and protected by the prothorax 

 in others; eyes usually large and transverse; beak never long, frequently 

 so short as to be not apparent. Labrum feebly developed, sometimes visible. 



Prothorax truncate in front, exposing the head, (Platppodidce, Scolytini 

 and Uylurgini), or prominent, convex and rounded (most Tom'cini); lat- 

 eral edge not distinct,* and prosternal sutures obliterated; flanks excavated 

 for the partial reception of the front legs in Platypodidce; coxal caviiies 

 usually confluent; separated in a few genera. 



Mesosternum triangular, pointed behind, or slightly truncate, episterna 

 {Platypodidce,) excessively large, ascending between the base of the pro- 

 thorax and elytra with the epimera small, posterior and transverse, or with 

 the suture very indistinct; coxae rounded, not widely separated. 



Metasternum long, sometimes, {Platypodidce) very long; side pieces 

 parallel, or nearly so, not dilated in front. 



Legs moderate in length, rather stout, front coxaj almost always con- 



*Exccpt in S-oljjtus. Eutomus, as ha.s been elsewhere observed is not a Rhj'ii- 

 chophorous insect but allied to Rhipiclandrus. 



