NORTH AMERICAN COLEOPTERA. 1!)" 



In addition to the species of the preceding group P. quisfjuiliarius 

 Gyll. is said by Fauvel (Faune Gallo-Rhenanc, Staphylinides, p. 464) to 

 occur in California. I haTe never seen any native specimens. 



c 



Anterior tarsi of male dilated ; dorsal series of thoracic punctures five. 



In this series the tarsi of the male are at most widely dilated, never 

 patellate, as observed in some species of B. The anterior tarsi of the 

 females are also dilated, but to a less extent than in the males, and rarely 

 are almost as slender as in the next series. The last ventral segment of 

 the male is always emarginate, sometimes feebly, the emargination often 

 surrounded by a depressed margin or gutter, which may extend in the 

 form of sulcus along the middle of the segment. In hriinneus the 

 emargination is unusually large for so small a species, and almost semi- 

 circular in outline. P. alumnus is remarkable in having the penultimate 

 ventral segment of the male notched at middle, a character of very rare 

 occurrence, and known otherwise in P. grandicollls^ a species of the pre- 

 ceding series. 



The principal difficulty in the determination and separation of species 

 is found in the forms most closely allied to lomaftis, from the fact that 

 the latter is variable in color and sculpture in its very extended distribu- 

 tion. 



Males with tlie last segment alone emarginate 2. 



Males with the last two segments emarginate; species rather small, variable in 



color, densely punctured alumnus. 



2. — Els'tra clear red, sometimes also thorax red 3. 



Elytra dark red or black; antennae and usually the legs black 4. 



General color piceous, legs and base of antennae paler 5. 



3.— Thorax entirely or in great part red. 



Thorax nearly parallel, very little larger than the head, and distinctly nar- 

 rower than the elytra iniiocniis. 



Thorax distinctly narrowed in front, 'much larger than the head, and as wide 



as the base of the elytra thoraciciis. 



Thorax black. 



Thorax very obviously narrowed in front; body fusiform. ...riisiforiliis. 

 Thorax scarcely narrowed in front; general form parallel. 



Smaller elytra more opaque ; antennse at base and legs pale yellow. 



fulvipes. 



Larger more shining; antennse and legs piceous OCCidciltalis. 



4. — Larger species, the abdomen above very conspicuously and more coarsely 

 punctured than the elytra; legs black; antennre slender; thorax 

 very obviously narrower in front. 

 Anterior tarsi % narrowly dilated. 



(50) 



