[Kingdom] Animalia Linnaeus, 1758 - animals
   Grade Enterozoa
     Grade Cœlomata
       Phylum Nematoidea
         [Class] Nematoidea Rudolphi, 1808 see Phylum Nematoda Gegenbaur, 1859
           [Family] Filaridæ
             Genus Spiroptera Rudolphi, 1819