Phylum Porifera Grant, 1836 - sponges Class Hexactinellida Schmidt, 1870 - hexactinellids Subclass Amphidiscophora Schulze, 1886 Order Amphidiscosa Schrammen, 1924 see Order Amphidiscosida Schrammen, 1924 Family †Stiodermatidae Finks, 1960 Genus †Rigbyella Mostler & Mosleh-Yazdi, 1976, nom. illeg.