THE GENUS PISSODES. 61 



the surface a grayish appearance. Posterior spot prominent, this 

 readily distinguishing it from its nearest alhes, P. alascensis and 

 P. rotundatus. 



Variations. — Length 7.4 to 9.4 mm. The color ranges from dark 

 brown to black. The color and density of the scales vary as usual, 

 as do also the elevation and rugosities of the alternating interspaces, 

 strial punctures, etc. Twenty-seven specimens of adults were 

 examined. 



Host trees. — Picea canadensis in the Black Hills of South Dakota. 

 It will evidently be found also in Picea engehnanni. 



Distribution (Plate XXI, fig. 22).— Black Hills of South Dakota; 

 central Colorado. 



23. Pissodes alascensis n. ap. 



The type specimen is labeled "Type No. 7459, U.S.N.M.;" 

 name; "Koyukuk R., Alas., Lt. 67-69, Lg. 151, summer 1901; 

 W. J. Peters, collector." 



Distinctive characters. — The darker color and closely placed yet 

 separated pronotal punctures, sparse elytral scales, and small pos- 

 terior spot on the elytra serve to distinguish the single specimen 

 of this species from P. coloradensis , and the distinctly elevated and 

 rugose elytral punctures distinguish it from P. rotundatus. One 

 specimen only was examined. 



Host tree. — Probably Picea. 



Distribution (Plate XXI, fig. 23).— (Hopk. U. S.) Alaslca: Ko- 

 yukuk River, Arctic Circle. 



24. Pissodes rotundatus Le Conte. 



(PlatelV, ng. 24.) 



This species is represented in the collection by a typical specimen 

 labeled with name; "■Marquette, Mich., 4, 7 [July 4]; Coll. Hubbard 

 &Schwarz; 9 4." 



Distinctive cTiaracters. — This species is closely allied to P. alascensis 

 from which it is distinguished by the densely placed punctures of the 

 pronotum and the broad and not strongl}" elevated third and fifth 

 elytral interspaces, which also serve to distinguish it from P. colora- 

 densis. 



Variations. — The length varies from 6 to 7.3 mm.; there is not 

 much variation in color except as it may be modified by the more 

 numerous white scales on some specimens. Seven specimens of 

 adults were examined. 



Host ^rees.— Probably Picea rubens ( ?) and Picea canadensis ( ?). 



Distribution (Plate XXI, fig. 24).— (U.S.N.M.) (H. &S.) Michigan: 

 White Fish Point, Mar(;[uette, June and July. 



