74 THE SCOLYTID BEETLES. 



SUBDIVISION A. 



Anterior and middle femora smooth; abdominal tergites 3 to 6 with small pleural spines; 



1 and 2 without distinct dorsal and lateral spines. Section a I, Species 1, 2, and 3. 



Anterior and middle femora with small apical spines Section a2. 



Section a> . 



Abdominal tergites 2 to 6 without distinct pleural spines; 7 and 8 with small gran- 

 ules Species 4. 



Abdominal tergites 2 to 6 with small pleural spines of equal size; 7 and 8 with small 



granules .*. . - - Species 5. 



Abdominal tergites 1 to 6 with small pleural spines, increasing in size; 7 and 8 smooth. 



Species 8. 

 SUBDIVISION B. 



Apex of anterior and middle femora with two spines Species 9. 



Apex of anterior and middle femora with one spine; abdominal spines and elytral 



rugosities coarser than in species 9 Species 10. 



Apex of anterior and middle femora with two spines; abdominal spines apparently less 



prominent than in species 9 and 10. Species 11. 



DIVISION II. 



Vertex of head fattened or faintly impressed ; apex of front and middle femora smooth 

 or with minute granule; abdominal tergites with pleural and dorsal spines moder- 

 ately prominent '. Subdivision C. 



Vertex of head convex; front and middle femora each with a minute pilated, subapical 

 granule; abdominal tergites with less distinct pleural and dorsal spines. 



Subdivision D. 

 SUBDIVISION C. 



Tergal spines of abdomen with pale or white tips; segment 7 smooth Section a3. 



Tergal spines of abdomen with pale, dark, or black tips; segment 7 with a few setigerous 

 granules Section a4 . 



Section a3. 



Anterior and middle femora with minute apical spines; abdominal tergites 2 to 6 with 

 stout, prominent pleural spines; 3 to 6 with prominent dorsal spines. Species 12. 



Anterior and middle femora without apical spines; abdominal tergites 2 to 6 with mod- 

 erately stout pleural spines, and 3 to 6 with small dorsal ones Species 13. 



Section a4. 



Vertex of head moderately impressed; anterior and middle femora without apical spines; 



abdominal tergites 2 to 6 with very small pleural spines; 4 to 6 with small dorsal 



spines, all with pale tips Species 14. 



Vertex of head distinctly impressed; abdominal tergites 2 to 6 with distinct pleural 



spines, and 3 to 6 with distinct dorsal ones Species 15. 



Abdominal tergites 2 to 6 with very small pleural, lateral, and dorsal spines, all with 



dark tips Species 17. 



SUBDIVISION D. 



Abdominal tergites 1 to 6 with moderately small pleural spines, 2 to 6 with small dorsal 



and lateral ones, all with pale tips Species 22. 



Same as preceding, except spines have darker to black tips Species 23. 



