Phylum Nematoda Gegenbaur, 1859 - round worms
   Class Secernentea Von Linstow, 1905
     Subclass Tylenchia (Thorne, 1949) Inglis, 1983
       Order Tylenchida G. Thorne, 1949
         Suborder Tylenchinaᵀ Chitwood, 1950
           Infraorder Anguinata Siddiqi, 2000
             Superfamily Anguinoidea Nicoll, 1935 (1926)
               Family Anguinidae Nicoll, 1935 (1926)
                 Subfamily Anguininae Nicoll, 1935 (1926)
                   Genus Orrina Brzeski, 1981