Metazoa Haeckel 1874 - multicellular animals see Kingdom Animalia Linnaeus, 1758 Bilateria Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888 Phylum Acoelomorpha Ehlers, 1985 - acoelomorphs see Subphylum Acoelomorpha Ehlers, 1985 1 Acoela Uljanin, 1870 - acoels see Class Acoela Uljanin, 1870 2 Order Nemertodermatida Karling, 1940 - nemertodermatids