MegalophaedusaMegalophaedusa is a genus of medium-sized air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Clausiliidae, the door snails, all of which have a clausilium.This genus occurs in Japan.SpeciesSpecies within the genus Megalophaedusa include: Megalophaedusa concrescens Megalophaedusa hickanis mikawa Pilsbry 1905Megalophaedusa hiraseana Megalophaedusa martensi * Megalophaedusa martensi tinctilabris Megalophaedusa spelaeonis Megalophaedusa vasta Boettger 1877 ''Megalophaedusa yokohamensis''