36 H. C. FALL. 



longer than wide; discal costse fairly distinct, intercostal areas all 

 with confused punctuation, the first nearly three times as wide at 

 base as the sutural interspace. Pygidium not densely punctate; body 

 beneath sparsely finely punctate at middle, more closely at sides. 

 Upper tooth of front tibia midway between base and apical tooth, or 

 very slightly nearer the base. Ungual tooth moderately large, ob- 

 liquely truncate at apex, nearly twice as far from the base as from . 

 the end of the claw. Length 7.8-10 mm.; width 4.2-5.4 mm. 



This is apparently a fairly common species in the northwest 

 quarter of the United States. The following localities are 

 represented in the material at hand: Nebraska (one example 

 — Bowditch collection) ; Helena, Montana (many examples — 

 Hubbard and Schwarz) ; Nevada (one example — National 

 Museum collection) ; Washington (one example — Dury col- 

 lection) ; California (three examples — Leng collection) . 



Of the four species with broadly convex or subconvex men- 

 turn — mentalis, conformis, residua and tenebrosa — the present 

 one is the most robust and the only one that is always black 

 or virtually so. Conformis is always brown of some shade, 

 never truly black, and is the narrowest in form. Mentalis 

 alone possesses the clypeal ridge, and is the only one in which 

 the upper tooth of the front tibia is obviously nearer the apex 

 than the base. The terminal joint of the maxillary palpi is 

 most elongate in mentalis, in which it is more than three 

 times as long as wide, and there is a gradual decrease through 

 conformis' and residua to rather less than twice as long as wide 

 in tenebrosa. 



21. D. costulata n. sp. 



Piceous black, rarely brown or ferruginous, densely punctate, the 

 elytra alutaceous and dull or feebly shining. Mentum broadly rather 

 deeply concave anteriorly, the margin of the concavity arcuate pos- 

 teriorly and reaching a little behind the middle, without raised line, 

 the punctures of the arcuate series fine and indistinct, and as a rule 

 non-setiferous. Head densely punctate, front with transverse post- 

 clypeal convexity above which it is bi-impressed; clypeal margin 

 sinuate at middle. Prothorax twice as wide as long, sides parallel for 

 a short distance at base, then broadly arcuately convergent anteriorly, 

 all the angles evidently impressed; punctuation similar to that of the 

 head and nearly as dense, the punctures separated by less than their 

 own diameters, except rarely. Elytra three and one-third times as 

 long as the prothorax, slightly wider posteriorly; discal costas unusually 



