Phylum Porifera Grant, 1836 - sponges Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885 Subclass †Lithistida Schmidt, 1870 Order Spirosclerophorida Reid, 1963 Suborder Rhizomorina Zittel, 1895 Superfamily Scleritodermatoidea Sollas, 1888 Family Seliscothonidae Schrammen, 1924 Genus †Pachyselis Schrammen, 1924