Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         ["Animale Regnum" nom. inval. - animal kingdom] see Kingdom Animalia Linnaeus, 1758
           [Class "Aves" Plinius, nom. inval. - birds] see Class Aves Linnaeus, 1758
             [Order "Anseres" nom. inval.] see Order Anseres Linnaeus, 1758
               [Genus "Mergus" nom. inval.] see Genus Mergus Linnaeus, 1758
                 1 "Mergus" nom. inval.
                 2 "Merganser" nom. inval.