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 "Accipitres" Plinius, nom. inval.] see Order Accipitres Linnaeus, 1758 [Genus "Psittacus" nom. inval.] see Genus Psittacus Linnaeus, 1758 1 "Psittacus" Plinius, nom. inval.