Phylum Porifera Grant, 1836 - sponges Class Hexactinellida Schmidt, 1870 - hexactinellids Subclass Amphidiscophora Schulze, 1886 1 Order Amphidiscosa Schrammen, 1924 see Order Amphidiscosida Schrammen, 1924 2 Order Reticulosa Reid, 1958 3 Order †Hemidiscosa Schrammen, 1924 [monotypic]