THE GENUS DENDROCTONUS. 135 



Revisional notes. It is quite evident that the specimens described 

 by Mannerheim(1853, p. 238) under D. rujipennis are D. borealis. The 

 single specimen in Le Conte's collection under D. rujipennis, labeled 

 ".Hylurgus rujipennis Kirby," and locality Kenai, is evidently from 

 Mannerheim's collection, and probably one of the specimens before 

 him when he prepared his description under that name. Superfi- 

 cially, this specimen resembles D. piceaperda, which led Le Conte to 

 identify his Anticosti and Canada specimens as D. rujipennis, and is 

 evidently the one which represented the Alaska locality in his revi- 

 sions (1868 and 1876). 



The immature stages and galleries of this species have not been 

 observed. 



Host tree. Picea canadensis. 



Distribution (fig. 83). Alaska: Eagle, (?) Kenai Peninsula. 



Identified specimens. Le Conte, 1 specimen; U.S.N.M., 2; Hopk. 

 U. S., 2, collected by W. H. Osgood, of the Biological Survey, U. S. 

 Department of Agriculture, at Eagle, Alaska, August, 1903, from 

 white spruce. 



BIBLIOGRAPHY AND SYNONYMY. 



Hylurgus rujipennis (not of Kirby). Mannerheim, 1853, p. (in part). 

 Dendroctonus rujipennis (not of Kirby). Le Conte, 1868-1876 (in part). 

 Dendroctonus borealis Hopkins, 1902a, p. 3, manuscript name only. 



17. Dendroctonus obesus (Mannerheim). 



(PI. VI, fig. 17.) 



Adult. Typical female : Length 6.5 mm., nearly black. Head with 

 front convex, with faint anterior and posterior impression and mod- 

 erately distinct anterior line. Elytral declivity with striae not deeply 

 impressed; punctures of pronotum distinctly irregular; posterior half 

 of proepisternal area not punctured; punctures of pronotum and 

 elytra moderately coarse; elytral striae scarcely impressed; inter- 

 spaces flat, finely, sparsely rugose on dorsal area and toward base of 

 vertex. Secondary sexual characters: Declivity convex, subopaque; 

 striae faintly impressed, with punctures moderately distinct; inter- 

 spaces faintly convex, with distinct row of granules. 



Typical female labeled, name label, "Hopk. 1/22/08, Picea sitch- 

 ensis, Queen Charlotte II., Keen [collector], 9 ." 



Typical male: Length 6.7 mm., black. Front convex, with faint 

 anterior impression and distinct anterior line. Agrees with female, 

 excepting that the punctures of elytral striae and interspacial rugosi- 

 ties are coarser; declivity subopaque; strial impressions and punc- 

 tures obscure; interspaces flat, faintly punctured, and with a few 

 granules toward vertex; pronotum with distinctly elevated line. 



Typical male labeled, name label, " 1/22/08, Picea sitchensis, Queen 

 Charlotte II., J. H. Keen, Collr., $ ." 



