Abstract
Part of the genus Lioconcha Mörch, 1853 is reviewed. Species strongly resembling Lioconcha castrensis (Linnaeus, 1758) are discussed and two new species are described: Lioconcha arabaya n. sp. from the Northwest Indian Ocean and Lioconcha rumphii n. sp. from Thailand and Sumatra. These three species, together with Lioconcha macaulayi Lamprell & Healy, 2002, share many morphological similarities and we suspect them to be closely related. They are referred to as the Lioconcha cast-rensis species group. Furthermore, lectotypes of Venus castrensis Linnaeus, 1758, and Venus fulminea Röding, 1798, are desig-nated. The latter is considered a junior synonym of V. castrensis.