Phylum Porifera Grant, 1836 - sponges Class Demospongiae Sollas, 1885 - demosponges Order Lithistida Schmidt, 1870 - lithistids see Subclass Lithistida Schmidt, 1870 Suborder Tetracladina Zittel, 1878 1 Family †Radiocellidae Senowbari-Daryan & Wurm, 1994