Casey — Observations on the Staphylinidae. 278 



Antennae slender, the penultimate joint very nearly as long as wide 2 



2 — Antennae long, extending nearly to the middle of the elytra; form, colo- 

 ration and sculpture nearly as inpieta but more slender, the head black, 

 the prothorax piceous, paler along the basal margin, the elytra gener- 

 ally infumate everywhere except toward the humeri ; head small; pro- 

 thorax three -fourths wider than long, broadly rounded at the sides and 

 narrowed anteriorly, the sides distinctly converging toward base, the 

 latter broadly arcuate, becoming sinuate near the angles as usual, the 

 subbasal impression fine, transverse and bisinuate, feebly, anteriorly 

 bifurcate at the middle; elytra slightly wider and scarcely one-half 

 longer than the prothorax, impressed and punctured nearly as in picta, 

 the humeri slightly more exposed at base ; abdomen nearly similar but 

 with each of the pale basal tergites more distinctly infumate at the mid- 

 dle of the base. Length 2.6-3.0 mm. ; width 0.75-0.78 mm. New Yorlc 

 (Catslilll Mts.) to Iowa (Iowa City). l=Bolitochara bl. Csy.], 



blanchardl Csy. 

 Antennae shorter and less developed, scarcely extending to basal third of 

 the elytra; form, coloration and sculpture nearly as In blanchardi hnl 

 smaller in size, and, in general, of darker color, the prothorax more 

 blackish and scarcely at all paler along the base, the subbasal double 

 impression larger and more distinct; elytra always black except broadly 

 toward base, the dark color also involving the scutellum as a rule, the 

 form and sculpture as in blanchardi; abdomen similar to the latter 

 throughout. Length 2.7 mm.; width 0.77 mm. Missouri (St. Louis) 

 and Iowa laetala n. sp. 



These species are very closely allied among themselves, 

 presenting diflSculties in classification similar to those well 

 known in Sericoderus^ of the Corylophidae. In hlanchardi 

 the medial, transversely convex carina of the fifth tergite ex- 

 tends anteriorly but little beyond the middle of the plate, and, 

 posteriorly, nearly to the apical margin, the sixth tergite be- 

 ing broad at tip and only very feebly sinuate, or more pro- 

 perly sinuato-truncate, with the edge finely serrulate as usual. 

 The species are all very abundant as before remarked. 



Plenrotobia n. gen. 



In most of it3 characters, as well as general habitus and 

 ornamentation, this genus agrees very well with Venusa, but it 

 differs rather radically in the fact that|the third antennal joint, 

 instead of being small and forming a part of the slender basal 

 part, is here large, similar to the succeeding joints and simi- 

 larly sculptured and pubescent ; the basal joint of the hind 

 tarsi, also, is notably less elongate. The species live in fungi 



