Sigmocyathus R. BEDFORD& J. BEDFORD, 1936
Specimen-type: Coscinocyathus didymoteichus lectotype, TAYLOR, 1910, pl. 10, photo 58
Systematics:
Order: AJACICYATHIDA R. Bedford& J. Bedford, 1939
Suborder: AJACICYATHINA R. Bedford& J. Bedford, 1939
Superfamily: SIGMOCYATHOIDEA Krasnopeeva, 1953
Family: SIGMOCYATHIDAE Krasnopeeva, 1953
Note:
Presence in Antarctica isn't sure.