Phylum Porifera Grant, 1836 - sponges
   Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885
     Subclass Choristida Sollas, 1880 see Order Tetractinellida Marshall, 1876
       Order Plakinida Reid, 1968 see Order Homosclerophorida Dendy, 1905
         1 Family Plakinidae Schulze, 1880
         2 Family Thrombidae Sollas, 1887
         3 Family †Acanthastrellidae Schrammen, 1924 [monotypic]