Nemathelminthes Gegenbaur, 1859 see Phylum Nematoda Gegenbaur, 1859
   Class Nematoda Gegenbaur, 1859
     Subclass Secernentia (Von Linstow, 1905) Andrássy, 1976
       Order Rhabditida Chitwood, 1933
         1 Suborder Rhabditina Chitwood, 1933
         2 Suborder Cephalobina Andrassy, 1974
         3 Suborder Teratocephalina Andrassy, 1974
         4 Suborder Diplogasterina Paramonov, 1952 see Suborder Diplogastrina Paramonov, 1952