Bigyra Cavalier-Smith, 1998 Subphylum Opalozoa Cavalier-Smith, 1992 Infraphylum Placidozoa Cavalier-Smith, 2013 Superclass Opalinata Wenyon, 1926 1 Class Opalinea Wenyon, 1926 2 Class Blastocystea Zierdt, 1978 [monotypic]