Ponder, W.F. 1983 Rissoaform gastropods from the Antarctic and sub-Antarctic. The Eatoniellidae, Rissoidae, Barleeidae, Cingulopsidae, Orbitestellidae and Rissoellidae (Mollusca: Gastropoda) of Signy Island, South Orkney Islands, with a review of the Antarctic and sub-Antarctic (excluding southern South America and the New Zealand sub-Antarctic islands) species, British Antarctic Survey Scientific Reports, 108 (p.25)
Powell, A.W.B. 1979New Zealand Mollusca: Marine, Land and Freshwater Shells, Collins, Auckland (p.113)
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