Phylum Porifera Grant, 1836 - sponges Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885 Subclass †Lithistida Schmidt, 1870 Order Monalithistida Lagneau-Hérenger, 1955 Suborder †Megarhizomorina Schrammen, 1924 [monotypic] Family †Megarhizidae Schrammen, 1901 Genus †Megarhiza Schrammen, 1901