Metazoa Haeckel 1874 - multicellular animals see Kingdom Animalia Linnaeus, 1758
   Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
     Eubilateria Ax, 1987 see Clade Nephrozoa Jondelius, Ruiz-Trillo, Baguñà & Riutort 2002
       Lophotrochozoa Halanych, Bacheller, Aguinaldo, Liva, Hillis & Lake 1995 - lophotrochozoans
         Phylum Platyhelminthes Gegenbaur, 1859 - flatworms
           Catenulida Graff, 1905 - catenulid flatworms see Order Catenulida Meixner, 1924