SCOLYTIDES. 91 



SCOLYTIDES, 



A. Abdomen turned upward from second segment onward. 



Head with scarcely any trace of rostrum, more or less 

 visible from above ; antennae with seven joints to funiculus, 

 club compact ; eyes finely granulate, narrow ; pronotum 

 separate from sides of prothorax ; elytra without apical 

 declivity ; second abdominal segment as long as the next 

 two together ; third tarsal joint bilobed, Scolytus, Geoffr. 

 JB, Abdomen normal. 



a. Head globular, generally invisible from above. 



Eyes finely granulate ; pronotum not separate from sides 

 of prothorax ; anterior coxae placed close together ; third 

 tarsal joint simple ; metasternum more or less long, its 

 episterna narrow. 



jT. Funiculus of antennae with five joints. 



1, Apical declivity of elytra more or less hollowed 

 out. 



Mentum at least four times as long as broad, narrowed 

 behind middle, again dilated toward apex, anterior margin 

 cut very obliquely on each side, forming an acute angle ; 

 ligula commencing near middle of mentum and there as 

 broad as it, strongly narrowed in front, apex rounded ; club 

 of antennae rather small, separation of joints not very dis- 

 tinct, the sutures more or less curved ; eyes narrow, sinuate 

 in front ; second to fourth abdominal segments about equal 

 in size. T amicus, Latr. 



2. Apical declivity of elytra rarely slightly im- 

 pressed. 



A A. First joint of labial palpi not much longer 

 than second. 



a a. Maxillary lobes fringed with a few stiff, 

 pointed, tolerably straight bristles. 

 Ligula almost three times as long as broad, somewhat 

 narrowed behind middle ; first and second joints of labial 

 palpi nearly equal, third much narrower, slightly conical, 

 not shorter than second ; club of antennae with first joint 

 nearly round, second and third crescent-shaped ; second 

 tarsal joint a little shorter than first and third. 



Xylocleptes, Ferr. 

 h h. Maxillary lobes fringed with almost 

 straight, broad, thornlike teeth. 



