Systema naturæ - nature
   Universum - universe see [unranked] Mundus Plinius
     naturalia - natural bodies
       Regnum Animale nom. inval. - animal kingdom see Kingdom Animalia Linnaeus, 1758
         Class Insecta nom. inval. - insects see Class Insecta Linnaeus, 1758
           Order Aptera nom. inval. see Order Aptera Linnaeus, 1758
             Genus Pulex nom. inval. see Genus Pulex Linnaeus, 1758
               1 Pulex vulgaris nom. inval.