West Indian molluscs have been studied by the Department of Malacology of the Zoological Museum Amsterdam for many years. Recently new material collected by Brother M. ARNOLDO (A. N. BROEDERS) and Dr. P. WAGENAAR HUMMELINCK became available which was studied by the second author. During 1982 several West Indian islands were visited by the first author, and mollusc samples were taken on the islands Puerto Rico, St. Martin, Aruba, Curaçao and Bonaire. Material was collected in various biotopes, from the littoral zone down to about 50 m. Most of the micro-molluscs were sorted out from coral sand. In a sample, taken at 45 m depth off Bonaire, some interesting species were found. In this article we will describe a new species, belonging to a new genus, from that station.