Casey — Observations on the Staphylinidae. 19i 



late, the impressions wholly impunctate; head as long as wide, the 

 antennae fully three-fifths as long as the body, with all the joints 

 elongate, the first and third subequal in length and longer than the 

 second, the outer joints gradually slightly thicker and unusually 

 narrowed from their apices to their bases; prothorax rather longer 

 than wide, as wide as the head, the sides broadly rounded anteriorly, 

 becoming gradually and feebly convergent thence to the base, which 

 is arcuato-truncate; surface convex, very broadly and moderately 

 concave along the middle except toward apex; elytra transverse, 

 fully four-fifths wider than the prothorax but not quite as long, not 

 angulate externally at tip, the latter broadly emarginate at the 

 suture, the sides acutely elevated, the disk concave along the 

 margin ; abdomen large and elongate, parallel, with the sides some- 

 what arcuate, rather wider than the elytra; legs long and slender. 



Length 3.0 mm.; width 0.68 mm. California cayipeiiiiis Lee. 



Form very slender, shining, subglabrous, pale rufo-testaceous through- 

 out the body, legs and antennae, the abdomen with a large blackish 

 subapical cloud ; head very small, including the mandibles slightly 

 elongate, the antennae very slender, nearly as in cavipennis but less 

 enlarged toward tip; prothorax somewhat longer than wide, dis- 

 tinctly wider than the head, together with the latter very finely, 

 sparsely and asperulately punctate, the sides strongly rounded 

 anteriorly, thence distinctly converging to the truncate base, the 

 angles obtusely rounded ; surface narrowly and extremely obsoletely 

 impressed along the median line except anteriorly, also transversely 

 and arcuately impressed toward the middle before the basal margin; 

 elytra small, transverse, much shorter than the prothorax and scarcely 

 more than a third wider, the sides rounding toward base, the lateral 

 margins strongly elevated, the adjoining surface concave, more broadly 

 behind, the punctures very strongly asperate, moderately close-set, be- 

 coming feeble or subobsolete postero-externally; scutellum large, 

 broad, prominently elevated though but slightly convex; abdomen at 

 base as wide as the elytra, in the middle more than a fourth wider, the 

 sides parallel and strongly arcuate, the surface minutely, very remotely 

 punctulate throughout; legs slender. Length 2.8 mm.; width of abdo- 

 men 7.2 mm. California (Pomona) lativentris n. sp. 



The male sexual characters in cavipennis consist of. a strong 

 tubercle at the centre of the first tergite and a posteriorly 

 inclined spiniform tubercle near the extreme tip of the fifth, 

 its apex projecting beyond the segmental apex ; the sixth ven- 

 tral is obscured in the only male before me. Lativentris is 

 represented thus far in my collection by the female only. 

 Each of the strongly asperate tuberculiform punctures of the 

 elytra bears a short stiff inclined seta. It is probable that 

 the species of Trachyota are associated in some way with 

 ants, though I have no records from Mr. Fall on this subject. 



