STAPHYLINID.E 433 



domen black, the legs and elytral flanks flavo-testaceous; antennae 

 blackish, piceous at base, slightly longer than the head and prothorax, 

 slender basally, gradually distinctly incrassate distally, the outer joints 

 as long as wide; head small, elongate, as in the preceding but with the 

 tempora more converging behind the eyes, the arcuate part much more 

 basal; prothorax relatively smaller though distinctly wider than the head, 

 as wide as long, in outline as in lacustris, the three punctures small, equi- 

 distant; elytra large though evidently shorter than wide, as long as the 

 prothorax, at base distinctly, and at apex much, wider than the latter; 

 punctures rather dense and strongly asperate; abdomen parallel, slightly 

 narrowing only at apex, the punctures small, asperulate, close basally, 

 gradually sparse posteriorly; sixth ventral (cf) as in pumilio; anterior 

 tarsi very moderately dilated. Length (cf) 3.8 mm.; width 0.85 mm. 

 Montana (Helena), -Wickham. 



Closely resembles some other species of this group but distin- 

 guishable from lacustris by its relatively still smaller prothorax and 

 more slender antennae, and from pumilio by its narrower and more 

 posteriorly narrowed head, very much smaller prothorax and larger 

 elytra. 



Philonthus lautus n. sp. Rather stout and moderately large in size, 

 shining, bright rufous, the head and abdomen black; legs piceous, the 

 anterior coxae and anterior and middle femora pale rufous; antennae dull 

 rufous, gradually black basally, one-half longer than the head, thick but 

 subfiliform, the outer joints transverse; head rather large, quadrate, 

 fully as wide as long, the basal angles very broadly rounded; eyes at 

 one-half more than their own length from the base; prothorax evidently 

 though not much wider than the head, as long as wide, the base rounded, 

 widest behind the middle, where the sides are obtusely subangulate, 

 thence straight and convergent to base and apex, feebly in the former, 

 more strongly in the latter, sense; punctures small, not exactly in straight 

 line; scutellum blackish, moderate in size; elytra subparallel, about as 

 long as wide, fully as long and wide as the prothorax; punctures moderate, 

 not asperate and decidedly sparse; abdomen shining like the elytra, 

 parallel, rounding at apex, rather closely, not very finely punctate; tarsi 

 slender, the anterior only slightly thickened basally in the female and not 

 quite so much so as in the female of basalis. Length (9) 8.7 mm.; 

 width 1.6 mm. Wyoming (Cheyenne). 



This species is more closely allied to basalis Horn, than to any 

 other, but differs when compared with the female of basalis, in its 

 much larger, more quadrate head, much thicker and more trans- 

 verse outer antennal joints, larger prothorax, with subangulate 

 sides, more sparsely punctured elytra, much more strongly and 

 less closely punctured abdomen, longer legs and tarsi, larger size 

 of the body and black and not red basal joint of the antennae. 

 T. L. Casey, Mem. Col. VI, Nov. 1915. 



