Metazoa Haeckel 1874 - multicellular animals see Kingdom Animalia Linnaeus, 1758
   Phylum Platyhelminthes Gegenbaur, 1859 - flatworms
     Class Trematoda Rudolphi, 1808 - flukes see Infraclass Trematoda Rudolphi, 1808
       Order Digenea Carus, 1863
         "Cercaria" Müller, 1773, incertae sedis
           1 Lophocercariae
           2 Gasterostome cercariae
           3 Monostome cercariae
           4 Amphistome cercariae
           5 Distome cercariae