[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Nematoidea
         [Class] Nematoidea Rudolphi, 1808 see Phylum Nematoda Gegenbaur, 1859
           1 [Family] Ascaridæ Baird, 1853
           2 [Family] Strongylidæ Baird, 1853
           3 [Family] Trichinidæ nom. illeg.
           4 [Family] Filaridæ
           5 [Family] Mermithidæ Weinland, 1858
           6 [Family] Gordiidæ
           7 [Family] Anguillulidæ
           8 [Family] Enoplidæ Dujardin, 1845
           9 [Family] Chætosomidæ nom. illeg.