Phylum Porifera Grant, 1836 - sponges Class Hexactinellida Schmidt, 1870 - hexactinellids Subclass Hexasterophora Schulze, 1886 Order Lychniscosa Schrammen, 1903 see Order Lychniscosida Schrammen, 1903 Family †Pachyteichismatidae Schrammen, 1936 Genus †Mastospongia Quenstedt, 1877