Trogloconcha, a new genus of larocheine Scissurellidae (Gastropoda : Vetigastropoda) from tropical Indo-Pacific submarine caves

A new genus Trogloconcha is proposed for Trogloconcha ohashii, sp. nov. within the Larocheinae Marshall, 1993, a unique subfamily that lacks an anal slit or foramen among the Scissurellidae (Vetigastropoda). The new species inhabits gloomy to totally dark, shallow-water submarine caves and deep caverns and is distributed widely in the tropical to subtropical eastern Indian and western Pacific oceans. T. ohashii, sp. nov. has papillate cephalic tentacles unlike species of Larochea (the condition is unknown for Larocheopsis), has a small operculum, and does not show sexual dimorphism in shell features unlike species of Larochea and Larocheopsis. One modern species Trogloconcha tesselata, sp. nov. from Okinawa, Japan, and one late Oligocene species Larocheopsis marshalli Lozouet, 1998, from France, both represented by shell alone, are assigned to the new genus.