76 THK SCOLYTID BEETLES. 



Section o-i. 



Front, wit.h hi distinct transverse elevation; clypeus with distinct median impression. 



Species 12. 

 Front with distinct transverse elevation; clypeus with median impressed line. 



Species 13. 

 Section 0,4. 



Abdominal tergites 8 and 9 with rugose but unarmed plates; front with faint trans- 

 verse elevation anterior to middle; clypeus with median groove Species 14. 



Frontal elevation near the middle Species 15. 



Frontal elevation distinctly anterior to middle Species 16. 



Front with lateral impressions toward the anterior angles, and frontal elevation ante- 

 . rior to middle Species 19. 



Abdominal tergite 9 with dorsal plate; frontal elevation anterior to middle; clypeus 

 with median groove Species 21. 



SUBDIVISION D. 



Abdominal tergites 8 and 9 each with dorsal plate and armed with three permanent 

 teeth; front of head without elevation; clypeus with faint median groove. 



Species 22 and 23. 



SYNOPSIS OF GALLERY CHARACTERS. 



Egg galleries winding to straight; eggs isolated or in approximate groups, but never in 



masses; larval mines exposed or concealed in inner bark Division I. 



Egg galleries longitudinal, straight to slightly winding; eggs in groups or masses; larval 

 mines and pupal cells exposed in inner bark Division 1 1 . 



DIVISION I. 



Pupal cells in outer bark; eggs isolated, never in groups; egg galleries winding; larval 

 mines short, narrow to broad, exposed or concealed Subdivision A. 



Pupal cells in inner bark; eggs in approximate groups; egg galleries slightly winding 

 to straight; larval mines short, broad, always exposed Subdivision B. 



; SUBDIVISION A. 



Larval mines concealed in inner bark Section al. 



Larval mines exposed or concealed Section a2. 



Section al. 



Egg galleries subtransverse, winding Species 1. 



Egg galleries distinctly transverse Species 2. 



Section a2. 

 Larval mines exposed. 



Egg galleries longitudinal, winding Species 3. 



Egg galleries sublongitudinal, winding Species 4. 



Larval mines concealed. 



Egg galleries evidently transverse, or subtransverse, winding, with concealed 



larval mines Species 5. 



Egg galleries subtransverse, winding Species 6. 



Egg galleries longitudinal, winding, with transverse branches. . Species 7 and 8. 



SUBDIVISION B. 



Egg galleries winding to straight Species 9. 



Egg galleries usually straight Species 10 and 11. 



