Casey — Observations on the Staphylinidae. 163 



beiug extremely minute in some cases. The second group 

 (2), consisting of affluens alone, is characterized by a broader 

 though still rather narrow, process, normal and entire carina 

 and closer abdominal sculpture, with the close-set punctures 

 of the impressions moderately coarse and the third group (3), 

 composed of sculptiventris, is remarkably isolated by reason of 

 the unusually coarse deep and subconfluent punctures of the 

 abdominal impressions, the latter being deeper than in any 

 other group and also because of the normally wide though 

 rather abbreviated process with correspondingly longer me- 

 tasternal process, normal carina and fine dense punctures 

 throughout. The fourth group (4) consists of the three 

 species from imbricata to salicola, and is distinguished by a 

 peculiar imbricate sculpture of the abdomen, almost similar 

 to that of the European hipunctata 01., where, however, the 

 mesosternal process is much narrower and the basal joint of 

 the hind tarsi normally elongate; the process is of unusual 

 width and the basal joint of the hind tarsi very short in the 

 American species. The species from densivenfris to obsoles- 

 cens constitute another group (5), characterized by the bi-ini- 

 pressed, sparsely and irregularly punctate pronotum and nor- 

 mally wide process, and, finally, verna and others of the table, 

 the European iiitida Grav., and Inlineata Gyll., and a small, 

 apparently undescribed Mexican species before me, constitute 

 a special group (6), resembling the preceding in pronotal 

 sculpture but differing in the narrow, though normally cari- 

 nate, process, and generally finer sculpture of the abdominal 

 impressions; the process is indeed as narrow as in the first 

 group, but, except in acuminata, with less converging sides. 

 The last two groups are the only ones containing species of 

 very wide grographic distribution, all the others being con- 

 fined to special faunal regions. A very small species in my 

 cabinet, taken near the city of Mexico, constitutes still another 

 distinct group, having the fine abbreviated carina and narrow 

 process of the first group above defined, with the medially 

 biseriate and otherwise sparsely and unevenly punctate pro- 

 notum of the fifth and sixth groups, this being an additional 

 reason why the biseriately impressed pronotum of the last 



