Phylum Porifera Grant, 1836 - sponges Class Hexactinellida Schmidt, 1870 - hexactinellids Subclass Hexasterophora Schulze, 1886 Order Hexactinosa Schrammen, 1903 see Order Hexactinosida Schrammen, 1903 Family Cribrospongiidae Roemer, 1864 Genus †Guettardiscyphia Fromentel, 1860 Subgenus †G. (Guettardiscyphia) Fromentel, 1860