Alloeocarpa Michaelsen, 1900 (original description)
Alloeocarpa bridgesi Michaelsen, 1900 (original description)
Alloeocarpa emilionis Michaelsen, 1900 accepted as Alloeocarpa incrustans (Herdman, 1886) (original description)
Alloeocarpa intermedia Michaelsen, 1900 accepted as Alloeocarpa incrustans (Herdman, 1886) (original description)
Alloeocarpa zschaui Michaelsen, 1900 accepted as Alloeocarpa incrustans (Herdman, 1886) (original description)
Cynthia paessleri Michaelsen, 1900 accepted as Pyura paessleri (Michaelsen, 1900) (original description)
Cynthia stubenrauchi Michaelsen, 1900 accepted as Pyura stubenrauchi (Michaelsen, 1900) (original description)
Gynandrocarpa Michaelsen, 1900 (original description)
Gynandrocarpa unilateralis Michaelsen, 1900 accepted as Gynandrocarpa placenta (Herdman, 1886) (original description)
Molgula georgiana Michaelsen, 1922 (original description)
Molgula kophameli Michaelsen, 1900 (original description)
Molgula pulchra Michaelsen, 1900 (original description)
Paramolgula guttula Michaelsen, 1900 accepted as Eugyra kerguelenensis Herdman, 1881 (original description)
Paramolgula patagonica Michaelsen, 1900 accepted as Paramolgula gregaria (Lesson, 1830) (original description)
Polyzoa falclandica Michaelsen, 1900 accepted as Polyzoa opuntia Lesson, 1830 (original description)
Polyzoa gordiana Michaelsen, 1900 accepted as Polyzoa opuntia Lesson, 1830 (original description)
Polyzoa herdmani Michaelsen, 1900 accepted as Polyzoa opuntia Lesson, 1830 (original description)
Polyzoa lennoxensis Michaelsen, 1900 accepted as Polyzoa opuntia Lesson, 1830 (original description)
Polyzoa pictonis Michaelsen, 1900 accepted as Polyzoa opuntia Lesson, 1830 (original description)
Styela curtzei Michaelsen, 1900 accepted as Cnemidocarpa nordenskjöldi (Michaelsen, 1898) (original description)