Nemathelminthes Gegenbaur, 1859 see Phylum Nematoda Gegenbaur, 1859
   Class Nematoda Gegenbaur, 1859
     Subclass Torquentia
       Order Chromadorida Chitwood, 1933
         Suborder Chromadorina Filipjev, 1929
           47 Family Chromadoridae Filipjev, 1917
           48 Family Hypodontolaimidae de Coninck, 1965
           49 Family Choanolaimidae Filipjev, 1926