Subgenus Ocypus Leach, 1819

Leach, 1819: 172 (species included: cyaneus); Bernhauer and Schubert, 1914: 374 (subgenus of Staphylinus; authorship as Stephens, 1832; world catalog); Cameron, 1932: 180 (subgenus of Staphylinus); Scheerpeltz, 1933: 1381 (subgenus of Staphylinus, catalog supplement); Shibata, 1973: 62 (checklist of species of Taiwan); Coiffait, 1974: 420 (key to species of the western Palearctic Region); Shibata, 1984: 87 (checklist of species of Japan); Smetana and Davies, 2000: 21, 31, 42 (characters; checklist of species of north temperate region); Herman, 2001: 3355 (world catalog); Smetana, 2004: 674 (Catalog of Palaearctic Region); Smetana, 2007: 443 (key to species of China); Schülke & Smetana, 2015: 1089 (Catalog of Palaearctic Region, including the synonyms Nudabemus and Xanthocypus).

Type species: Staphylinus cyaneus Paykull, 1789, fixed by original designation and monotypy. Syn.: Goerius Westwood, 1827: 58 . Type species: Staphylinus olens O. Müller, 1764 by monotypy. Isopterum Gistel, 1856: 388 . Type species: Staphylinus cyaneus Paykull, 1789, fixed by subsequent designation by

Blackwelder, 1952: 2015.

Nudabemus Coiffait, 1982b: 74 . Type species Nudabemus caerulescens Coiffait, 1982, fixed by original designation. Xanthocypus J. Müller, 1925d: 40. Type species Ocypus weisei Harold, 1877 .

The species of the subgenus Ocypus s. str. can be easily distinguished from those of other subgenera of the genus Ocypus by the following characteristics: last segment of maxillary palpi asetose; that of labial palpi setose, usually short, with truncate apex; body size relatively large (more than 15 mm), body color usually totally black; palpifer usually with three setae on apical portion; eyes small and tempora relatively long; genal seta at least four puncture diameters away from posterior margin of eye; sternite 9 of male genital segment with tapered basal portion rather short and wide.

In the current taxonomy (Smetana and Davies, 2000; Herman, 2001; Smetana 2007; Schülke & Smetana, 2015), the subgenus Ocypus s. str. includes the synonyms Goerius Westwood, 1827, Isopterum Gistel, 1856, Nudabemus Coiffait, 1982, and Xanthocypus J. Müller, 1925. The taxonomic position of the name Xanthocypus was once challenged if it should be maintained within the subgenus Ocypus s. str. (Hayashi, 1993; Smetana 2007: “tentatively set aside as a possible junior synonym of Agelosus Sharp, 1889 ”), but this was not confirmed by later publications (Smetana, 2009; Schülke & Smetana, 2015). We therefore maintained it within the subgenus Ocypus s. str. and included here two Chinese species: Ocypus miwai (Bernhauer, 1943) and Ocypus weisei Harold, 1877 .