Belongs within: Olpioidea.
The Olpiinae are a subgroup of olpiid pseudoscorpions generally characterised by relatively short venom ducts (Harvey & Leng 2008).
<==Olpiinae [Olpiini, Xenolpiini]
|--Xenolpium Chamberlin 1930MHG08, HL08 [incl. Antiolpium Beier 1962H81]
| |--*X. pacificum (With 1907)HL08 [=Olpium pacificumJ97]
| |--X. insulare Beier 1940J97
| |--X. longiventer (Koch & Keyserling 1886) [=Olpium longiventer]J97
| |--X. novaeguineenseH83
| `--X. squalidum Beier 1966 [=Beierolpium squalidum]H81
`--+--Euryolpium Redikorzev 1938MHG08, HL08
| |--*E. agniae Redikortzev 1938H81
| |--E. granulosum (Hoff 1947) [=Xenolpium granulosum; incl. X. robustum Beier 1948]H81
| |--E. michaelseni (Tullgren 1909) [=Olpium michaelseni, O. michaelsoni, Xenolpium michaelseni]H81
| `--E. salomonis (Beier 1935) [=Xenolpium salomonis]J97
`--+--Beierolpium Heurtault 1977MHG08, HL08
| |--B. bornemisszai (Beier 1966)HL08 [=Xenolpium bornemisszaiH81]
| `--B. oceanicum (With 1907) [=Garypinus oceanicus]J97
`--Calocheiridius Beier & Turk 1952MHG08, HL08
`--C. termitophilus Beier 1964HL08
Olpiinae incertae sedis:
Olpium Koch 1873HL08
|--*O. pallipes (Lucas 1846) [=Obisium pallipes]H81
|--O. australicum Beier 1969H81
|--O. biaroliatumT89
|--O. fuscimanum Beier 1957J97
|--O. minnizioides Vachon 1966J97
`--O. tenue Chamberlin 1930 [=O. tenuis]J97
Antillolpium Muchmore 1991HL08
Austrohorus Beier 1996HL08
`--*A. exsul Beier 1966H81
Banksolpium Muchmore 1986HL08
Halominniza Mahnert 1975HL08
Heterolpium Sivaraman 1980HL08
Hoffhorus Heurtault 1977HL08
Horus Chamberlin 1930HL08
Indolpium Hoff 1945HL08
Leptolpium Tooren 2002HL08
Linnaeolpium Harvey & Leng 2008HL08
`--*L. linnaei Harvey & Leng 2008HL08
Minniza Simon 1881HL08
|--M. aequatorialis Beier 1944J97
|--M. barkhamae Mahnert 1991HL08
|--M. graeca (Koch 1873) [=Olpium graecum]J97
|--M. hirsti Chamberlin 1930J97
`--M. sola Chamberlin 1930 [=M. solus]J97
Neopachyolpium Hoff 1945HL08
Nipponogarypus Morikawa 1955HL08
Novohorus Hoff 1945HL08
`--N. obscurusM90
Olpiolum Beier 1931HL08
Parolpium Beier 1931HL08
Pseudohorus Beier 1946HL08
*Type species of generic name indicated
References
[H83] Hammen, L. van der. 1983. Contribution to the knowledge of the soil-fauna of New Guinea. Zoologische Verhandelingen 206: 1–36.
[H81] Harvey, M. S. 1981. A checklist of the Australian Pseudoscorpionida. Bulletin of the British Arachnological Society 5 (6): 237–252.
[HL08] Harvey, M. S., & M. C. Leng. 2008. The first troglomorphic pseudoscorpion of the family Olpiidae (Pseudoscorpiones), with remarks on the composition of the family. Records of the Western Australian Museum 24 (4): 387–394.
[J97] Judson, M. L. I. 1997. Catalogue of the pseudoscorpion types (Arachnida: Chelonethi) in the Natural History Museum, London. Occasional Papers on Systematic Entomology 11: 1–54.
[M90] Muchmore, W. B. 1990. Pseudoscorpionida. In: Dindal, D. L. (ed.) Soil Biology Guide pp. 503–527. John Wiley & Sones: New York.
[MHG08] Murienne, J., M. S. Harvey & G. Giribet. 2008. First molecular phylogeny of the major clades of Pseudoscorpiones (Arthropoda: Chelicerata). Molecular Phylogenetics and Evolution 49: 170–184.
[T89] Thorell, T. 1889. Viaggio di Leonardo Fea in Birmania e regioni vicine. XXI.—Aracnidi Artrogastri Birmani raccolti da L. Fea nel 1885–1887. Annali del Museo Civico di Storia Naturale di Genova, Serie 2a, 7: 521–729.