Casey — Observations on the Staphylinidae. 391 



Group II. 



Head polished beneath and strigilate with very fine wavy lines 2 



Head less shining beneath, where the surface is minutely but strongly retic- 

 ulate 11 



S — Prothorax never paier in color than the elytra 8 



Prothorax paler than the elytra, the latter relatively smaller and distinctly 

 shorter than the prothorax 10 



8 — Body black or piceous-black in color, the elytra never more than slightly 

 paler 4 



Body black or blackish, the elytra always conspicuously pale 8 



4 — Elytra each with two isolated, parallel and subentire series of dorsal 

 punctures, the punctures toward the suture more or less broadly or 

 completely confused In arrangement; body moderately large in size.. 5 



Elytra each with three more or less complete isolated series of dorsal 

 punctures, the latter more narrowly confuted along the suture; body 

 very small in size 7 



5 — Body moderately slender and convex, polished, deep black, the protho- 

 rax very dark rufo-piceous, the elytra somewhat less dark than the pro- 

 thorax; legs dark rufous, the antennae dusky; head oblong, parallel, 

 distinctly longer than wide behind the antenna-, the basal angles broad- 

 ly rounded, the punctures deep but only moderately coarse or close- 

 set; flattened post-ocular line well defined, strongly and closely punc- 

 tate; punctures of the under surface distinct though not very coarse, 

 rather sparse, still sparser toward the sutures; prothorax somewhat 

 narrower than the head, evidently though not strongly narrowed pos- 

 teriorly throughout, a third longer than wide, the angles rather narrowly 

 rounded; serial punctures close-set and strong, 8-11 in number in the 

 dorsal series and about as numerous in the sublateral, both series end- 

 ing anteriorly in confused clusters of smaller punctures, a larger punc- 

 ture near the side and apical third is also obvious; elytra not quite as 

 long as the prothorax but much wider and distinctly wider than the 

 head, longer than wide; abdomen slightly narrower than the elytra but 

 wider than the head; finely punctulate laterally as u^ual. Length 4.8- 

 6.6 mm.; width 0.8-1.08 mm. Rhode Island and Ontario to northern 

 New Mexico, Colorado, Nevada, Idaho and Manitoba. l=obscurus Er.]. 



hamatas Say 



Body deep black throughout, the elytra scarcely perceptibly paler, the 

 antennae black and the legs dark rufo-piceous in color ; elytral punctures 

 less broadly aggregated along the suture 6 



— Form rather stouter, the size larger, as in hamatus; head as in that 

 species, with the punctures similar but less close- set, being separated 

 toward the sides by three times their own widths but becoming smaller 

 and closely aggregated in a broad line along the upper margin of the 

 post -ocular flattened line, the latter strongly, .somewhat closely punc- 

 tured; under surface rather finely but distinctly, sparsely punctate, the 

 punctures obsolete toward base; prothoriax as in hamatus, slightly 

 narrower than the head but with the sides less obviously converging; 

 elytra nearly similar but less distinctly wider than the prothorax and 



