Phylum Porifera Grant, 1836 - sponges
   Subphylum Hexactinellida Schmidt, 1870 see Class Hexactinellida Schmidt, 1870
     Class Hexasterophora F.E. von Schulze see Subclass Hexasterophora Schulze, 1886
       Order Hexactinosida Schrammen, 1903
         Family Tretodictyidae Schulze, 1886
           Genus Anomochone Ijima, 1927
           Genus Auloplax Schulze, 1904
           Genus Cyrtaulon Schulze, 1886
           Genus Hexactinella Carter, 1885
           Genus Psilocalyx Ijima, 1927
           Genus Sclerothamnopsis Wilson, 1904
           Genus Sclerothamnus Marshall, 1875
           Genus Tretocalyx Schulze, 1901
           Genus Tretodictyum Schulze, 1886
           Genus Tretorete Ijima, 1927 see Genus Stereochlamis Schrammen, 1912