THE GENUS DENDROCTONUS. 71 



SUBDIVISIONT B. 



Pronotum with deep punctures. 



Length 3.7 to 6.4 mm.; brownish to black; elytra with strige moderately impressed, 

 punctures usually small or moderately coarse and distinct. North and west of 

 northwestern Colorado, southward to Yosemite National Park, California, in 



Pinus 9. monticolse Hopk., page 105. 



Length 4.5 to 7 mm.; black; elytral strite distinctly impressed, punctures dis- 

 tinct and coarse. Black Hills, South Dakota, southward through Colorado 

 and southern ITtah, into New Mexico and Arizona, in Pinus and Picea. 



10. ponderosse Hopk., page 109. 

 Pronotum with small shallow punctures. 



Length 6 to 8 mm. ; black; punctures of elytral striae distinct throughout; pronotum 

 distinctly shining. Yosemite National Park, California, in Pinus jeffreyi and 

 P. ponderosa 11. jeffreyi n. sp., page 114. 



DIVISION II. 



Front usually with posterior impression; pronotum with large and small punctures 



intermixed Subdivision C, pages 71, 117. 



Front without posterior impression; pronotum with regular punctures. 



Subdivision D, pages 72, 146. 

 Subdivision C. 



Elytral declivity with striae deeply impressed; epistomal process narrow, flat, with 

 lateral sections nearly parallel; pronotum with punctures moderately regular, 



and with long hairs on dorsal and lateral areas Section a3, page 71. 



Elytral declivity with striae not deeply impressed; epistomal process broad, concave, 

 and the lateral sections oblique; punctures of pronotum distinctly irregular. 



Section a4, page 71. 

 Section aS. 



Pronotum with coarse punctures. 



Length 3.5 to 5 mm.; reddish to brown; pronotum with short dorsal and lateral 

 hairs; apex of epistomal process not extending beyond the anterior frontal 

 margin. New Brunswick to Michigan and West Virginia, in Larix. 



12. simplex Lee, page 117. 

 Pronotum with fine, shallow punctures. 



Length 4 to 7 mm.; reddish to dark brown; pronotum shining, with long dorsal 

 and lateral hairs; apex of epistomal process usually extending beyond the 

 anterior margin of epistoma. British Columbia southward to Texas, westward 

 to California, in Pseudotsuga and Lai'ix 13. pseudotsugae Hopk., page 121. 



Section a4. 



Posterior half of proepisternal area not distinctly punctured. Subsection b3, page 71. 

 Posterior half of proepisternal area distinctly punctured Subsection b4, page 72. 



Subsection hS. 



Length 4.7 to 6 mm.; body stout; reddish to black; elytral striae quite distinctly im- 

 pressed toward sides, with punctures coarse and distinct; interspaces convex; 

 rugosities acute, rather closely placed, irregular. New Brunswick, through 

 Canada, New England, and Michigan, in Picea. . . 14. piceaperda Hopk., page 126. 



Length 5 to 7 mm.; reddish to black, shining; punctures of prothorax and elytra 

 coarser; striae of lateral area not distinctly impressed, the interspaces scarcely 

 convex or rugose. Idaho and Black Hills, South Dakota, to New Mexico and 

 westward to California, in Picea 15. engelmanni n. sp., page 130. 



