The shell and anatomy of a new genus and species of Lymnaeidae, Kutikina hispida, are described from the Franklin River, S.W. Tasmania and the implications of this discovery, along with the origins and relationships of the Australasian Lymnaeidae, are discussed. The new species lives attached to submerged limestone rock, has a very expanded shell aperture and, uniquely, the periostracum bears short hairs. In addition there are apomorphic radular and anatomical characters separating this genus from other lymnaeids. The new genus is compared with the other native Australian Lymnaeidae. It is suggested that the taxonomy of the only other native Tasmanian species of Lymnaeidae, Austropeplea tomentosa, a species widely distributed in temperate Australia and in New Zealand, requires reexamination. Alternative hypotheses relating to the zoogeography of the southern members of the family are discussed in relation to this taxon and the Recent genus-group taxa of lymnaeids are listed in an Appendix and their differences from the new genus noted.