Phylum Radiolaria Müller, 1858 see Subphylum Radiozoa Cavalier-Smith, 1987
   Superclass Polycystina Ehrenberg, 1838 see Superclass Polycystinia Ehrenberg, 1838
     Class Sphaerellaria Haeckel, 1881
       Order Sphaerellata Haeckel, 1887
         Family Xiphostylidae Haeckel, 1881
           Subfamily Stylosphaerinae Haeckel, 1881
             1 Genus Druppatractus Haeckel, 1887
             2 Genus Lithomespilus Haeckel, 1881
             3 Genus †Praestylosphaera Empson-Morin, 1981
             4 Genus †Protoxiphotractus Pessagno, 1973
             5 Genus Spongatractus Haeckel, 1887
             6 Genus Stylatractus Haeckel, 1887
             7 Genus Stylosphaera Ehrenberg, 1847
             8 Genus Xiphatractus Haeckel, 1887