Phylum Porifera Grant, 1836 - sponges
   Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885
     Subclass †Lithistida Schmidt, 1870
       Order Tetralithistida Lagneau-Hérenger, 1962
         Suborder †Didymmorina Rauff, 1893 [monotypic]
           Family †Cylindrophymatidae Schrammen, 1936
             1 Genus †Chonophyma Oppliger, 1921
             2 Genus †Coscinodiscus Schrammen, 1936
             3 Genus †Cylindrophyma Zittel, 1878
             4 Genus †Linochone Schrammen, 1936
             5 Genus †Melonella Zittel, 1878