[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Platyelmia
         Branch Suctoria
           Class Trematoidea
             Order Monogenea see Infraclass Monogenea
               1 Genus Aspidogaster von Baer, 1826
               2 Genus Polystoma Zeder, 1800