Discocharopa aperta (Möllendorff, 1888) (Pulmonata, Charopidae) on Madeira

While inspecting leaf litter and surface soil which he had collected 15.II.1983 on the island of Madeira, 1.5 km W. of Matur along the road to the airport, the second author found a fresh looking, very small, adult, endodontoid shell and a shell-fragment obviously representing the same species. The specimens (kept in the private collection of the second author) proved to belong to Discocharopa aperta (Möllendorff, 1888), a species hitherto known from “the northern Philippines and Java to Central Australia, Kermadec Islands, and the Society Islands” (Solem, 1982: 75). Most probably D. aperta has been introduced on Madeira. D. aperta has been redescribed and figured very thoroughly by Solem (1982: 74-81, figs. 5a-f, 34a-d, 35a-b, 36a-c, 37a-d). The shell is discoidal with a slightly elevated spire and does not exceed 1.9 mm in diameter. Its surface is covered by radial riblets; on the protoconch there is an additional spiral microsculpture, whereas the teleoconch shows additional microradials only. There may be a parietal lamella inside the aperture.