Two rare species of Amalda (Gastropoda: Olividae: Ancillinae) collected by the R.V. Tansei-Maru from Japanese waters

We report two rare species of Amalda, A. otohime n. sp. and A. parentalis (Shikama and Oishi) on the basis of materials collected by the R.V. Tansei-Maru from Japanese waters. It is very difficult to distinguish Amalda otohime from Amalda urasima (Kira) by shell characteristics alone, but the former species can be distinguished from the latter by its operculum that bears a centrally situated nucleus. Amalda parentalis, originally described based on material from the Pleistocene of Kikai-Jima Island, southwestern Japan, is recorded in the modern fauna for the first time. Both A. otohime and A. parentalis were first introduced in works that did not constitute publications within the meaning of the International Code of Zoological Nomenclature (ICZN). These inappropriate proposals have resulted in nomenclatural confusion in subsequent studies.