The adult form of Wardius zibethicus, parasitic in the cecum of the muskrat, has been described by Barker and East. This species is regarded as Pseudodiscus zibethicus by Fukui and Meyer and Penner. However, Wardius differs from the genus Pseudodiscus in respect to three characteristics. ...These characteristics seem to warrant separation of the two genera. A detailed description of the cercaria and intrasnail stages of Wardius zibethicus will be published with details of the life cycle.