THE GENUS DENDROCTONUS. 85 



kins, 1903b, p. 281, mentioned. Hopkins, 1904, p. 18, habits, distribution, etc. 

 \\Vbb, 1906, bulletin, Pis. II, III, figs. 7-12, stages and vork illustrated, full 

 account of habits, life history, etc. Hopkins, 1908, pp. 162-163, depredations. 



Dendroctonus frontalis (not of Zimm.) Dietz, 1890, p. 32 (in part), California. 



Dendroctomis brevicornis Dietz, 1890, p. 32 (in part), California. 



2. Dendroctonus barberi n. sp. 



(PI. Ill, fig. 2.) 



Adult. Type of species, female: Length, 4.5 mm.; very dark 

 brown. Elytra and elytral declivity without long hairs. Head with 

 front convex, with slight elevation each side of a faint median groove. 

 Elytral rugosities moderately coarse and dense; striae distinctly 

 impressed. Pronotum with a few long hairs on the anterior half of 



.e lateral area, the remaining area with very fine and short pubes- 

 .ce. The secondary sexual characters are the same as in the 

 eding species. 



Type labeled "Type No. 7444, U.S.N.M.," name label, u Hopk. 



15/08, 9 , individual /, Barber & Schwarz, Collectors], Williams, Ar., 

 .6" ( = June7). 



Male type: Length, 4 mm. Front with prominent tubercles each 

 side of a distinct groove. Pronotum without transverse ridge across 

 the anterior area, but with a broad transverse impression. The 

 elytral declivity shining, with strial punctures distinct and interspaces 

 slightly more rugose than in the female. 



Male type labeled " $ type," otherwise same as female, except type 

 number. 



Variations. Length 2.5 to 4.7 mm., color from brownish to black. 

 The frontal and prothoracic variations are similar to those of D. 

 brevicomis. The elytra vary from rugosities moderately coarse and 

 obtuse to distinctly coarse and acute, and striae from moderately to 

 very distinctly impressed, and the punctures from obscure to distinct. 



Distinctive characters. The adults of D. barberi are at once distin- 

 guished from the next species by the absence of long hairs on the ely- 

 tral declivity, and from D. brevicomis, to which it is closely allied, by 

 the prevailing coarser rugosities of the elytral interspaces and the 

 distinctly impressed striae. Some systematists might concede these 

 characters of no more than subspecific or varietal value, but it must 

 be remembered that in this genus there is a close general resemblance 

 of allied species and that the characters which in other genera would 

 be of special value in specific distinction are so variable and incon- 

 stant in this as to be of no value. Therefore any constant or prevail- 

 ing character of distinction, even if it does seem insignificant, is of 

 vastly higher value than would otherwise be allowable, especially 

 when it is supported by differences in physiological characteristics. 



