Accepted by J. Klimaszewski: 28 Oct. 2016; published: 7 Dec. 2016 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2016 Magnolia Press Zootaxa 4205 (3): 265–274 http://www.mapress.com/j/zt/ Article 265 http://doi.org/10.11646/zootaxa.4205.3.6 http://zoobank.org/urn:lsid:zoobank.org:pub:66FB30C3-66BC-4D79-9361-03F5C9F22498 Review of Scydmaenus (Geoscydmaenus) of Madagascar (Coleoptera, Staphylinidae, Scydmaeninae) PAWEŁ JAŁOSZYŃSKI Museum of Natural History, University of Wroclaw, Sienkiewicza 21, 50-335 Wroclaw, Poland. E-mail: scydmaenus@yahoo.com Abstract Two species of Scydmaenus (Geoscydmaenus) are known to occur in Madagascar, but original descriptions do not allow for unambiguous identification. Based on the type specimens and a recently collected additional material, Sc. isaloensis Franz and Sc. madagassicus Franz are redescribed. Several differences between these species listed by Franz had been misinterpreted; consequently species diagnoses are emended. Morphological structures of Geoscydmaenus are illustrated and discussed, and it is concluded that in future this taxon may be elevated to genus rank. However, as morphological structures of most subgenera of Scydmaenus remain exceptionally poorly studied and knowledge of character variability is scarce, it is too early to reclassify this large genus. Key words: Insecta, Scydmaenini, taxonomy, Afrotropical Introduction The Afrotropical subgenus Geoscydmaenus Franz, 1961 of Scydmaenus Latreille, 1802 was established for a single species collected in the Orientale Province of the Democratic Republic of the Congo. The subgenus was defined in a rather unclear way, by comparison to Scydmaenus (presumably Scydmaenus s. str., but this was not explicitly stated) and Pseudoeudesis Binaghi, 1948. Diagnostic characters of Geoscydmaenus mentioned by Franz were: the exceptionally small body not reaching 1 mm, strongly elongate body form, small eyes, absent wings, light pigmentation, protarsi of males broadened, trochanters shorter than those in Scydmaenus but longer than in Pseudoeudesis, "free" metanepisterna, and the aedeagus similar to that of Pseudoeudesis. Later, five more species were placed in Geoscydmaenus (Newton & Franz 1998), some of them with males and females not differing in the structure of protarsi, so this character was excluded from the original diagnosis. The miniaturization, depigmentation, reduction of eyes and wings were suggested by Franz (1961) to reflect a presumably subterraneous life of Geoscydmaenus, despite the fact that the type species was collected by sifting the surface layer of leaf litter. Microphthalmous, exceptionally small, wingless or depigmented species are known in other subgenera of Scydmaenus and these characters alone are not suitable to define a subgenus. Recently a large sample of Scydmaeninae collected in Madagascar was made available for my study, including a series of Geoscydmaenus sp. As there are only two species of this subgenus known to occur in Madagascar, it seemed an easy task to identify the new material. However, the diagnoses given by Franz (1986) turned out to be inadequate and examination of the type specimens was necessary. This, together with examination of the type species of Geoscydmaenus, revealed that the subgeneric diagnosis should be emended to include more reliable characters than those used by Franz, and that the diagnosis of one of the Madagascan species was based largely on misinterpreted characters, whereas important features truly different and valuable for discrimination were overlooked. The goal of this study is to provide a documentation of morphological structures of Geoscydmaenus that can be used in future work on reclassification of the large genus Scydmaenus, and to redescribe two Madagascan species and consequently facilitate further study of the Scydmaeninae fauna of one of the most important world biodiversity hotspots.