Small land snails from Northern Australia, III: Species of Helicodiscidae and Charopidae

Abstract

Two taxa of Indonesian origin and main distribution, the helicodiscid snail Stenopylis coarctata (Moellendorff, 1894) and the charopid Discocharopa aperta (Moellendorff, 1888), extend across northern Australia. They appear generally dispersed, reaching southern limits in the Napier Range and near Halls Creek, Western Australia; somewhat south of Alice Springs, Northern Territory; and then south to near Mackay, Queensland or into the north-eastern corner of New South Wales, respectively. Both species have been described several times. A second charopid, Pilsbrycharopa tumidus (Odhner, 1917), also is of New Guinea-Indonesian affinities. It has been recorded from a single collection on an island in the Fitzroy River on Noonkanbah Station, Western Australia. A third charopid, Dupucharopa millestriata (Smith, 1874) has been recorded once from Depuch Island, east of Roebourne, Western Australia. It has not been dissected, but shell features suggest that it also is of northern affinities. None of these appear to be closely related to any of the southern Australian charopid radiations.