Basileostylus bollonsi, common name the New Zealand flax snail or , is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Bothriembryontidae.MolluscaBase eds. (2021). MolluscaBase. Basileostylus bollonsi (Suter, 1908). Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=863080 on 2022-01-22
Distribution This species is endemic to the Three Kings Islands group off the northern tip of New Zealand's North Island.
Subspecies A number of subspecies were recognised; Placostylus bollonsi arbutus and P. b. bollonsi are classified by the New Zealand Department of Conservation as being Nationally Endangered, while Placostylus bollonsi caperatus is classified as Nationally Critical.
Buckley et al. (2011) found based on molecular phylogeny research and shell morphology research, that there are no subspecies of Placostylus bollonsi.Buckley T. R., Stringer I., Gleeson D., Howitt R., Attanayake D., Parrish R., Sherley G. & Rohan M. (2011). "A revision of the New Zealand Placostylus land snails using mitochondrial DNA and shell morphometric analyses, with implications for conservation". New Zealand Journal of Zoology 38(1): 55-81. .
References
Further reading Suter, H. (1908). A new Placostylus from New Zealand. Transactions of the New Zealand Institute, 40: 340-343, pl. 25.