Phylum Radiolaria Müller, 1858 see Subphylum Radiozoa Cavalier-Smith, 1987
   Superclass Polycystina Ehrenberg, 1838 see Superclass Polycystinia Ehrenberg, 1838
     Class Nassellaria Ehrenberg, 1847
       Order Cyrtidinata Haeckel, 1862
         Superfamily Eucyrtidioidea Ehrenberg, 1847
           Family †Xitidae Pessagno, 1977
             1 Genus †Clavaxitus Dumitrica, 1997
             2 Genus †Crolanium Pessagno, 1977
             3 Genus †Foremanina Empson-Morin, 1981
             4 Genus †Neorelumbra Kiessling, 1995
             5 Genus †Novixitus Pessagno, 1977
             6 Genus †Praexitus Dumitrica, 1997
             7 Genus †Pseudoxitus Wu & Pessagno, 1993
             8 Genus †Tugurium O'Dogherty, 1994, nom. illeg.
             9 Genus †Xitus Pessagno, 1977