The systematics, Biology and Zoogeography of the land snail fauna of Great Island, Three Kings Group, New Zealand

Abstract

A brief bibliographic account is given of land snail literature relating to the Three Kings Islands. The distribution, ecology, variation and zoogeography of the land snail fauna of Great Island is discussed, eight new species are described, and the anatomy of most species is illustrated for the first time. The opportunity has been taken to figure the types of some New Zealand species of Paralaoma Iredale which have never been adequately illustrated. Suterilla neozelanica (Murdoch, 1899) is transferred from the Assimineidae to the Tutuilanidae. Cytora kiama, Pseudaneitea ramsayi, P. pallida, Delos regia, D. striata, Paralaoma pagoda, Charopa (Egestula) bicolor and C. (E.) microgaza are described as new species. Dissection of the achatinellid snail Tornatellinops novoseelandica (Pfeiffer, 1852) has shown that Tornatellinops Pilsbry and Gooke, 1915, is best treated as a subgenus of Lamellidea Pilsbry, 1910, and that the lamellideinine tribes Lamellideini Cooke and Kondo, 1960, and Tornatelloptini Cooke and Kondo, 1960, are both synonyms of the Lamellideinae. Thalassohelix regia Gardner, 1968, is transferred to the punctine genus Laomarex Powell, 1948, Paralaoma lateumbilicata (Suter, 1890) is deleted from the fauna of Great Island and Therasiella Powell, 1948, is transferred from the Phenacohelicinae to the Charopinae. The Three Kings Group of islands have b~n effectively isolated from the New Zealand mainland by marine straits since the Pliocene, the degree of endemism in the land snail fauna is high (86.2%—25 of 29 species) and zoogeographic affinities are predominantly with the northernmost tip of Northland, itself an island during the Pliocene.