Phylum Radiolaria Müller, 1858 see Subphylum Radiozoa Cavalier-Smith, 1987 Superclass Polycystina Ehrenberg, 1838 see Superclass Polycystinia Ehrenberg, 1838 Class Spumellaria Ehrenberg, 1875 Order †Spongiata Afanasieva & Amon, 2003 Family †Spongentactiniidae Nazarov, 1975 Subfamily †Retentactiniinae Won, 1997 Genus †Retentactinia Won, 1997