[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Appendiculata {Lankester}
         Branch Chætopoda
           Order Archisyllidea
             1 Genus Saccocirrus Bobretzky, 1871
             2 Genus Polygordius Schneider, 1868