Porifera Grant, 1836 - sponges Hexactinellida Schmidt, 1870 - hexactinellids Hexasterophora Schulze, 1886 Hexactinosa Schrammen, 1903 see Order Hexactinosida Schrammen, 1903 Tretodictyidae Schulze, 1886 Tretodictyinae Schulze, 1886 ?†Prohexactinella Moret, 1926