MULTISENTIS-MYRMECOBIUS, GEN ET SP-NOV (ACANTHOCEPHALA, OLIGACANTHORHYNCHIDAE), FROM THE NUMBAT, MYRMECOBIUS-FASCIATUS, AND A KEY TO GENERAOF THE OLIGACANTHORHYNCHIDAE

A new genus and a new species of acanthocephalan are described from th e numbat Myrmecobius fasciatus, a termite-eating marsupial from south- western Australia. Multisentis myrmecobius belongs to the family Oliga canthorhynchidae and a key to the genera of this family is given. The life cycle is presumed to involve termites as the intermediate host. T he definitive host-parasite relationship is assumed to have evolved si nce the origins of M. fasciatus from ancestral marsupial forms before the late Miocene.