Casey — Observations on the Staphylinidae. 315 



fifths wider than the head, nearly two-thirds wider than long, the 

 sides rather strongly converging from base to apex, evenly and some- 

 what strongly arcuate, the surface not impressed ; elytra fully as wide as 

 the prothorax and a third longer; abdomen at base much narrower 

 than the elytra, strongly acd evenly tapering thence to the apex, with 

 the sides straight, the first two impressions distinct, subequal, the 

 third obsolete. Length 1.7 mm.; width 0.55 mm. Colorado (Boulder 



Co.) ancilla n. sp. 



Form much less stout and convex, more linear, small in size, shining, pale 

 testaceous, the head slightly darker, the abdomen feebly infumate 

 pojiteriorly except at apex; legs and the antennae gradually toward 

 base pale testaceous; punctures very minute but somewhat sparse, 

 slightly less minute and cloter on the elytra, moderately close-set on 

 the abdomen; pubescence short, rather inconspicuous; head wider 

 than long, iuflated at base, the eyes unusually small, not at all promi- 

 nent; antennae scarcely longer than the head and prothorax, the sub- 

 apical joints transverse, the second very much longer than the third ; 

 prothorax about two-thirds wider than the head and one-half wider 

 than long, the sides becoming distinctlv convergent and less arcuate 

 toward apex, the surface not impressed; elytra transverse, at base 

 slightly narrower than the prothorax, at apex about equal in width, 

 about equal in lecgth, rather depressed; abdomen at base almost as 

 wide as the elytra, parallel to the middle, then slightly tapering to the 

 tip, the three basal impressions distinct. Length 2.0 mm. ; width 0.51 

 mm. Missouri (St. Louif) simnlans n, sp. 



13 — Form moderately slender, convex, alutaceous, very finely, closely 

 punctate, the punctures of the elytra and abdomen unusually asperate ; 

 pubescence very short and somewhat inconspicuous throughout; color 

 pale rufo-teslaceous, the head ard entire abdomen black; legs and 

 antennae pale, the latter infuscate and feebly incrassate apically, ex- 

 tending to basal third of the elytia, the subapical joints transverse, 

 the second much longer than the first or third ; head mo re shining, orbic- 

 ular, convex, about as long as wide, the eyes well developed, slightly 

 convex; prothorax about one-half wider than the head, barely one- 

 half wider than long, the sides feebly and evenly arcuate but only 

 moderately converging from base to apex and much less so than in the 

 the two following species, the surface with a small rounded discal im- 

 pression before the ecutellum; elytra at base slightly narrower than 

 the prothorax but at apex fully as wide, between a fourth and a third 

 longer; abdomen at base evidently narrower than the elytra, feebly 

 tapering posteriorly only behind the middle, the second and third im- 

 pressions very feeble. Length 2.4 mm.; width 0.62 mm. Missouri (St. 

 Louis) - trnncatella n. sp. 



Form less slender, feebly shining, piceous-black, the abdomen black, nu- 

 bilously pale at the apices of the fifth and sixth dorsals; legs and an- 

 tennae pale, the latter infuscate distally; punctures very fine, close-set, 

 those of the elytra equally dense but larger and more asperate, the 

 asperities of the abdomen elongate; pubescence fine, very short, rather 

 dark, sericeous; head slightly transverse, distinctly inflated at base, the 

 eyes rather small, not prominent; antennae about as long as the head 



