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 Genus †Coscinodiscus Schrammen, 1936