Botryllus gracilis Michaelsen, 1927 accepted as Botrylloides anceps (Herdman, 1891) (original description)
Cnemidocarpa hartogi Michaelsen, 1927 accepted as Cnemidocarpa irene (Hartmeyer, 1906) (original description)
Microcosmus squamiger Michaelsen, 1927 (original description)
Polycarpa abjornseni Michaelsen, 1927 accepted as Polyandrocarpa abjornseni (Michaelsen, 1927) (original description)
Polycarpa hartmeyeri Michaelsen, 1927 (original description)
Pyura albanyensis Michaelsen, 1927 accepted as Pyura gangelion (Savigny, 1816) (original description)
Stolonica australis Michaelsen, 1927 (original description)