Imperium naturæ C. Linnaeus, 1758 - nature
   Mundus Plinius - physical world
     naturalia - natural bodies
       Regnum Animale C. Linnaeus, 1758 - animal kingdom see Kingdom Animalia Linnaeus, 1758
         Class Vermes Linnaeus, 1758 - worms see Phylum Vermes (C. Linnaeus, 1758)
           Order Intestina Linnaeus, 1758
             Genus Hirudo Linnaeus, 1758
               Hirudo stagnalis Linnaeus, 1758