Casey — Observations on the Staphylinidae. 229 



the surface very feebly and finely impressed along the median line to- 

 ward base; antennae rather long but strongly and gradually incrassate 

 distally, the first three joints subequal in length, the subapical slightly 

 transverse, equal in length, the eleventh about as long as the two pre- 

 ceding combined, pointed; prothorax only moderately narrowed toward 

 base, very finely and rather feebly impressed along the median line, not 

 transversely impressed before the scutellum, the sulcus ending poste- 

 riorly in a very slight enlargement ; hypomera as in Falagria, clearly 

 delimited from the pronotum by an entire beaded edge ; elytra large or 

 small, the humeri more or less widely exposed ; scutellum flat, granu- 

 larly sculptured; abdominal impressions moderately and not densely 

 punctured; legs slender, the hind tarsi long, slender and filiform, the 

 basal joint much elongated, the next three rapidly decreasing in length. 

 Pacific coast of America Falagrlota 



The succession of genera in the above table seems to be 

 fairly in accordance with natural affinities. The first three 

 genera and Aneurota are highly specialized types, without 

 any close allies, Gardiola differing from any other genus of 

 the subtribe in its deep mesocoxal cavities, which are very 

 abruptly excavated on all sides ; Lophagria is wholly peculiar 

 in its strongly carinate mesosternum and Chitalia differs 

 from any other in the uniform elevation of the entire meso- 

 stemum above the surfaces posterior thereto. Aneurota is 

 wholly isolated in tarsal structure and in general habitus. 

 The small subcoxal plates of Falagriota^ which comes last in 

 the series, may be either rudimentary or vestigial. I incline 

 to the opinion that we have here a case of arrested develop- 

 ment, due to some obscure environmental condition, basing 

 this supposition upon the hypothesis that the archetypes of 

 the present subtribe came into being somewhere within the 

 nearctic regions and migrated to Europe by way of Green- 

 land. Such of the original stock as found its way to the Pa- 

 cific coast has, for some undiscoverable reason, lagged behind 

 in development and has remained in an almost primitive con- 

 dition as far as the subcoxal plates are concerned, constitut- 

 ing to-day the genus Falagriota. The genus Lissagria, also 

 inhabiting the Pacific coast regions, has progressed materially 

 further than Falagriota in the development of these singular 

 protective plates, but is still somewhat behind the present 

 standard of other faunal regions. The foreign genera indi- 

 cated above are the following : — 



