Buckley, T.R., Stringer, I., Gleeson, D., Howitt, R., Attanayake, D., Parrish, R., Sherley, G.H., 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) (p.55)
Choat, J.H., Schiel, D.R. 1980 Population structure of Placostylus hongii (Gastropoda: Paryphantidae) on the Poor Knights Islands, New Zealand Journal of Zoology, 7(2) (p.199)
Powell, A.W.B. 1979New Zealand Mollusca: Marine, Land and Freshwater Shells, Collins, Auckland (p.350)
Key to Geographical Ranges
The symbols K.A.C.F.M.An. are used to indicate the geographical range of the species.
They have been adopted to give an approximation of the range of each species within New Zealand.
Aupourian - Kaipara Harbour, north around North Cape, encompassing the Three Kings Islands and south to East Cape
Cookian - Lower North Island and the northern part of the South Island