Nemathelminthes Gegenbaur, 1859 see Phylum Nematoda Gegenbaur, 1859
   Class Nematoda Gegenbaur, 1859
     Subclass Torquentia
       Order Chromadorida Chitwood, 1933
         Suborder Cyatholaimina
           50 Family Achromadoridae Gerlach & Riemann, 1973
           51 Family Ethmolaimidae Filipjev & Schuurmans Stekhoven, 1941
           52 Family Cyatholaimidae Filipjev, 1918