Phylum Porifera Grant, 1836 - sponges Class Hexactinellida Schmidt, 1870 - hexactinellids Subclass Hexasterophora Schulze, 1886 Order Lyssacinosa Zittel, 1877 see Order Lyssacinosida Zittel, 1877 ?Genus †Pyritonema McCoy, 1850