Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Porifera Grant, 1836 - sponges
     Class Hexactinellida Schmidt, 1870 - hexactinellids
       Subclass Amphidiscophora Schulze, 1886
         Order Amphidiscosida Schrammen, 1924
           1 Family Hyalonematidae Gray, 1857
           2 Family Monorhaphididae Ijima, 1927 [monotypic]
           3 Family Pheronematidae Gray, 1870