The Glacidorbidae (Mollusca: Gastropoda: Heterobranchia) of Australia

Abstract

The heterobranch gastropod family Glacidorbidae (?Pulmonata) is known only from temperate Australia and Chile. The Australian taxa are reviewed and three new genera, Benthodorbis, Striadorbis and Tasmodorbis are described based on differences in their shells, especially the protoconchs, and in their opercula and radulae. Nineteen species of Australian glacidorbids are recognised, all but four of them new. Of the four Australian species previously included in Glacidorbis, only two, G. hedleyi (Iredale) from New South Wales and Victoria, and G. occidentalis Bunn & Stoddart from south Western Australia, are retained in that genus. Eleven new species of Glacidorbis are described, seven from Tasmania (G. bicarinatus, G. catomus, G. atrophus, G. decoratus, G. costatus, G. tasmanicus and G. circulus), one (G. isolatus) from New South Wales, two (G. otwayensis and G. rusticus) from Victoria and one (G. troglodytes) from South Australia. Striadorbis contains the Tasmanian S. pedderi (Smith), and two new species, S. spiralis from western Victoria and S. janetae from Tasmania. Benthodorbis contains two species, both from old lakes in Tasmania; B. pawpela (Smith) from Great Lake and B. fultoni from Lake Sorell. Tasmodorbis contains a single species found in western Tasmania, T. punctatus, unique in having internal shell pores. Glacidorbis costatus is known only from Pulbeena Swamp in NW Tasmania and appears to be recently extinct, possibly as a result of draining of the swamp in the early part of this century. A cladistic analysis with the South American member of the family, Gondwanorbis, as the outgroup, supports the monophyly of the genera recognised.