1987 Volume 46 Issue 4 Pages 194-201
Monodonta perplexa boninensis n. subsp. is described and its form and habitat are observed. This new subspecies is endemic to the Ogasawara Island and has a flatter shell with less constricted sutures and lighter greencolor surface than M. perplexa perplexa from Japanese temperate region. Its habitat is a lower intertidal zone in boulder beaches, although M. perplexa perplexa inhabits a middle intertidal zone.