Phylum Porifera Grant, 1836 - sponges Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885 Subclass Ceractinomorpha Lévi, 1953 see Class Demospongiae Sollas, 1885 Order Vaceletida Finks & Rigby, 2004 Family †Solenolmiidae Engeser, 1986 Subfamily †Solenolmiinae Engeser, 1986 Genus †Polythalamia Debrenne & Wood, 1990