Casey — Observations on the Staphylinidae. 197 



the ante-abdominal part of the body, feebly and gradually incrassate, 

 the first three joints equal in length, much elongated, the tenth per- 

 ceptibly longer than wide; prothorax slightly wider than the head, fully 

 two-fifths wider than long, the sides broadly rounded anteriorly, thence 

 unusually feebly converging to the base, the surface rather narrowly 

 and distinctly impressed along the median line except apically and with 

 a short and very feeble transverse impression before the base, also with 

 four small rounded impressions forming a very large median quadri- 

 lateral — perhaps accidental in the type; elytra two-fifths wider and 

 one- half longer than the prothorax, the humeri only moderately exposed 

 and rounded, the post-scutellar impression rather small and feeble; 

 abdomen parallel, much narrower than the elytra, the basal impressions 

 of the first three tergites wholly impunctate toward the raised basal 

 margin but with a transverse irregular series of somewhat close-set 

 coarse punctures posteriorly, the fourth tergite also narrowly impressed 

 and slightly more coarsely punctate along the basal margin; legs 

 rather long and slender, the hind tarsi three-fourths as long as the 

 tibiae, with the first three joints rapidly decreasing in length, the second 

 and fifth equal. Length 2.8 mm.; width 0.68 mm. Pennsylvania. 

 l=Tachyusa nig. Lee] uigrella Lee. 



Form more depressed, very highly polished, deep blue-blacli throughout, 

 the legs nearly black with the tarsi paler, the antennae piceous-black; 

 punctures very fine, rather close-set, inconspicuous, especially on the 

 abdomen; pubescence very short and indistinct; head nearly as in 

 nigrella, the eyes smaller and less prominent, the impression broader, 

 the antennae stouter but less incrassate distally, extending to the mid- 

 dle of the elytra, the third joint slightly longer than the second and 

 both much shorter than the stouter fusiform first joint, the tenth barely 

 as long as wide; prothorax transverse, slightly wider than the head, the 

 sides broadly subangulate anteriorly, thence moderately converging and 

 broadly sinuate to the base, the surface unimpressed along the median 

 line, but with an unusually large wide transverse impression before 

 the base, the impression confusedly punctulate at each side of the 

 middle; elytra relatively very large, one-half wider and two-thirds 

 longer than the prothorax, the humeri widely exposed and rectangular, 

 the post-scutellar impression large, broad and strong; abdomen very 

 much narrower than the elytra, parallel and straight at the sides, the 

 teasal impressions coarsely but not very closely punctured and still less 

 closely toward the basal margins; legs slender, the tarsi nearly as in 

 nigrella; sixth ventral sharply angulate at tip in the female, the male 

 HOt known. Length 2.6 mm.; width 0.75 mm. New York (Catskill 

 Mts.) atrolacens Csy. 



11 — Body sublinear but somewhat stout, convex, moderately shining, 

 piceous-black in color, the antennae but little paler though paler 

 toward base, the legs brown; punctures minute and very close -set 

 throughout; pubescence very short but dense and distinct; head rather 

 small, the sides converging and arcuate behind the eyes to the base, 

 the vertex feebly flattened and broadly less punctate anteriorly, with a 

 small feeble impression at the middle ; antennae long, stout, strongly 

 incrassate distally, the third joint much longer than the second and as 



