82 



Distribution. — Alaska, British Columbia, and southwards into Cali- 

 fornia. 



A common secondary enemy of pines and spruces. 



Hylurgops porosus Lee; Am. Ent. Soc. Trans., 2: 175, 1868, (Hylastes). 



A large, elongate species, with a deep frontal impression, and coarsely 

 sculptured, hairy elytra; length, 5 mm., width, 1-8 mm. ; the pronotum 

 nearly as wide as the elytra, widest at the middle; the elytral bases feebly 

 arcuate; the male more coarsely sculptured and more densely scaly on the 

 declivity. 



Host trees. — Western White Pine, in British Columbia, and probably 

 other pines. 



Distribution. — British Columbia (Arrowhead) ; Western States, Wash- 

 ington, California, New Mexico (in our collection), Utah (a rather distinct 

 variation). Rare in British Columbia. 



Hylurgops lecontei Sw.; Dom. Ent. Br., Dept. Agric, Bull. 14: 16, 1917. 



Length, 4- 1 mm.; width, 1-6 mm. Allied to porosus Lee, but smaller, 

 with the pronotal punctures coarser and denser and the striae less deeply 

 impressed on the declivity. 



Host trees. — Western Yellow Pine, and apparently also Lodgepole Pine. 



Distribution. — British Columbia (Okanagan Lake, Golden, Atlin); 

 Colorado; Nevada; New Mexico. 



Hylurgops subcostulatus Mannh.; Bull. Mosc, 239, 1853, (Hylastes); Leconte' 

 Am. Ent. Soc. Trans. 2: 176, 1868 (Hylastes), species fixed; alternans Chap., 

 Syn. Scol., 22, 1869 (Hylastes). 



Length, 3-4 to 4-5 mm.; easily distinguished by the characters given 

 in the key; an aberrant species, removed from the true Hylurgops through 

 the arcuate, subserrate bases of the elytra, the longer 2nd abdominal seg- 

 ment, and the alternately carinate elytral interspaces. 



Host trees. — Lodgepole Pine, Western Yellow Pine, Western White 

 Pine, and probably all species of Pinus within its range. 



Distribution. — Coast region and southern interior of British Columbia, 

 extending throughout Western United States into New Mexico and Arizona. 



THE MICRACIN-ffi. 



The Genus Thysanoes Leconte. 

 Am. Phil. Soc. Proc, 15: 369, 1876. 



Thysanoes rigidus Lee; loc. cit., 362 (Cryphalus), 1876. 



Dark brown, somewhat shining; the form stout, cylindric. 



The head with the front closely punctured, with short pubescence, 

 deeply concave and shining below; the antennal club large, outer face with 

 suture 1 semicircular, 2 narrowly angled, 3 more broadly angled, the 

 funicle 6-segmented, the scape densely hairy on the outer side. 



The pronotum little wider than long, convex, anterior edge not toothed, 

 disc with a few distinct, small, acute tubercles in front of the middle, rather 

 closely and coarsely punctured behind; strongly rounded behind, very 

 strongly narrowed towards the rounded front margin, subtriangular from 

 above. The elytra coarsely punctured in rows, with fine strial setae; inter- 

 spaces roughly though finely punctured with uniseriate rows of bristles, 

 granulate on the declivity; declivity rounded, oblique, the summit near 

 the middle of the elytra. The first two ventral segments swollen and convex, 

 subequal and each longer than the last three together. Fore tibiae slender^ 



