91 



BB The punctures of the pronotum extremely minute, almost obsolete; 



the front of the head strongly convergently aciculate; the minute 



rugulations of the elytra very dense. sulcatus Lee. Page 91. 



A A With the elytral declivity not distinctly retuse; only very feebly sulcate 



along the suture. 



B The pronotum moderately rough in front; the length about 3 mm. 



, materiarius Fitch. Page 91. 



BB The pronotum strongly roughened in front; a very small species, 



length, 1-5 mm. asperulus Lee. Page 91. 



Gnathotrichus retusus Lee; Am. Ent. Soc. Trans., 2: 155, 1868 {Cnjphalus). 



Of the form of materiarius, but usually larger; length, 3-6 mm. to 

 3-8 mm. The female has the front of the head moderately convex, de- 

 limited above b}^ a curved line, coarsely not densely punctured, with a 

 smooth, shghtly elevated median space ending in an acute, minute epistomal 

 process; the antennae with a few, long, slender, hairs from the dorsal margin 

 of the funicle and club. The male has the front of the head with the smooth 

 median space longitudinally, very finely and feebly aciculate towards the 

 epistoma; with the antennal pubescence normal. (PL 18, fig. 17). 



Host Trees. — Western Hemlock, Douglas Fir, Western Yellow Pine. 



Distribution. — Generally distributed through southern British Columbia 

 and southward through the Rocky Mountain and Pacific Coast regions. 



Gnathotrichus sulcatus Lee; Am. Ent. Soc. Trans., 2: 155, 1868 (Cryphalus). 



Very closely allied to retusus, but differing in the aciculate front, 

 more finely punctured pronotum and less strongly retuse declivity. The 

 front of the head is convex, shining above, with a median carina on the 

 vertex, very sparsely punctured, with the basal median area strongly, 

 convergently aciculate, the lines meeting at the slight median emargination 

 of the epistoma which bears a minute acute point at the base of which the 

 median lines terminate; the antennal club and funicle with a few long, 

 marginal hairs, in the female, with the antennal pubescence normal in the 

 male. 



Host Trees. — Grand Fir, Western Hemlock, Douglas Fir, Western 

 White Pine. 



Distribution. — Generally distributed throughout southern British 

 Columbia, extending southwards. In sapwood and heartwood of dying 

 and recently killed trees, and more rarely in those apparently sound. 



Gnathotrichus materiarius Fitch; Nox. Ins. N.Y. 4th Rep't, 40-42, 1858, 

 (Tomicus); corthyloides Eichh., Berl. Ent. Zeit., 273, 1868. 



Length, 2-5 mm. to 3-2 mm. The male with the median, smooth, 

 carinate space on the front minutely aciculate, and without long hairs on 

 the antennal club and funicle ; the female with the aciculation on the frontal 

 carina but with a few very long hairs on the dorsal margin of the club and 

 funicle. 



Host Trees. — Eastern Pines, Spruces, and Eastern Larch. 



Distribution. — Throughout Eastern Canada and Eastern United 

 States; apparently less abundant west of the Great Lakes. 



Gnathotrichus asperulus Lee; Am. Ent. Soc. Trans., 2: 155, 1868 (Cryphalus). 



A very small, slender species, 1-5 mm. long; the head flat, feebly 

 punctured; the pronotum one-half longer than wide, strongly roughened 

 in front, very finely sparsely punctured behind; the elytra faintly punctured 

 in rows; the declivity rather feebly sulcate. 



Host Tree. — Pinus inops, (Sz.). 



