Nemathelminthes Gegenbaur, 1859 see Phylum Nematoda Gegenbaur, 1859
   Class Nematoda Gegenbaur, 1859
     Subclass Penetrantia
       Order Dorylaimida Pearse, 1942
         1 Suborder Mononchina Kirjanova & Krall, 1969
         2 Suborder Dorylaimina Chitwood, 1933
         3 Suborder Diphtherophoridae
         4 Suborder Mermithina Andrassy, 1971