Brook, F.J., Marshall, B.A. 1998 The coastal molluscan fauna of the northern Kermadec Islands, southwest Pacific Ocean, Journal of the Royal Society of New Zealand, 28 (p.217)
Powell, A.W.B. 1979New Zealand Mollusca: Marine, Land and Freshwater Shells, Collins, Auckland (p.125)
Powell, A.W.B. 1934 The High-Tidal Mollusca of Rangitoto Island, Auckland; with descriptions of a new Genus and two new Species, Transactions and Proceedings of the Royal Society of New Zealand, 63 (p.146)
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 approxomation 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