Phylum Porifera Grant, 1836 - sponges
   Class Hexactinellida Schmidt, 1870 - hexactinellids
     1 Order Amphidiscosida Schrammen, 1924
     2 Order Hexactinosida Schrammen, 1903
     3 Order Aulocalycoida Tabachnick & Reiswig, 2000
     4 Order Lychniscosida Schrammen, 1903
     5 Order Lyssacinosida Zittel, 1877
     6 Order †Inaecoelida Senowbari-Daryan & García-Bellido, 2002 [monotypic] see Order Innaecoeliida Boiko, 1990