gg THE SCOLYTID BEETLES. 



lateral area, the remaining area with short, erect, and sparse pubes- 

 cence. Secondary sexual characters: Pronotum with transverse 

 ridge across the anterior area, extending to the sternum. Elytral 

 declivity shining; striae very slightly impressed; punctures obscure; 

 interspacial granules sparse and small, but distinct. 



Type labeled "Type No. 7445 U.S.N.M.," name label, "Hopk. 

 1/16/08, Pinus ponderosa, Hopkins, Coir., 9/8/02, Williams, Ariz., 9 , 

 Hopk. U. S. 1109." 



Male type : Length, 5.6 mm. Front convex and with f aint anterior 

 and posterior impressions, but without frontal groove or tubercles. 

 Pronotum without transverse elevation. Elytral declivity less shin- 

 ing; striae more impressed, with more distinct punctures and the inter- 

 spacial granules distinctly coarser than hi the female. 



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

 type number. 



Variations. The length varies from 4 to 6 mm., with the average 

 at about 5.5 mm. ; the color ranges from reddish to black, with red- 

 dish-brown prevailing; front ranges from completely convex without 

 median impression to more or less distinctly impressed, but never 

 with frontal tubercles. The punctures of the pronotum vary as 

 usual, and the dorsal area ranges from the absence of a longitudinal 

 median space or line to a distinct elevated line. 



Distinctive characters. The adults of D. convexifrons are at once 

 distinguished from D. approximatus by the more slender form and 

 shining appearance, and the prevailing convex front in both sexes, 

 which latter character also distinguishes small examples of the species 

 from large examples of D. arizonicus. The long hairs on the elytral 

 declivity render it absolutely distinct from D. barberi, to which it 

 appears to be more closely allied on account of pupal characters. 



Revisional notes. This species is not represented in the Le Conte 

 collection, but among the three specimens in the Horn collection, 

 under D. approximatus Dietz, there was one labeled "N. M.," which 

 certainly must be referred to it. 



Pupa. In addition to the divisional and subdivisional characters, 

 the front and middle femora are smooth or with minute apical 

 granule; abdominal tergites 1 and 2 without dorsal spines but with 

 one or two lateral granules; 2 to 6 with very small lateral spines, and 

 3 to 6 with very small dorsal and lateral spines, becoming more 

 prominent toward the sixth; 7 and 8 smooth and 9 with widely 

 separated caudal spines. Pupal type labeled "Hopk. U. S. No. 

 5090." 



Larva. In addition to the divisional characters, the front has a 

 median smooth, shining convexity; mandibles distinctly rugose on 

 lateral area toward base; labrum with apex broadly rounded and 



