Phylum Porifera Grant, 1836 - sponges Class Hexactinellida Schmidt, 1870 - hexactinellids Subclass Hexasterophora Schulze, 1886 Order Lyssacinosa Zittel, 1877 see Order Lyssacinosida Zittel, 1877 Family Pheronematidae Gray, 1870 1 Genus †Pheronema Leidy, 1868 2 Genus †Semperella Gray, 1868