Powell, A.W.B. 1979New Zealand Mollusca: Marine, Land and Freshwater Shells, Collins, Auckland (p.354)
Finlay, H. 1926 A Further Commentary on New Zealand Molluscan Systematics, Transactions and Proceedings of the Royal Society of New Zealand, 57 (p.444) Original Description
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.
K=
Kermadec Islands
A=
Aupourian - Kaipara Harbour, north around North Cape, encompassing the Three Kings Islands and south to East Cape
C=
Cookian - Lower North Island and the northern part of the South Island