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 Mollusca Linnaeus, 1758 see Phylum Mollusca Linnaeus, 1758
             Genus Echinus Linnaeus, 1758
               Irregulares: apertura ani subtus uti os
                 Echinus orbiculus Linnaeus, 1758
                   1 Foraminibus nullis pervius, lobatus
                   2 Foraminibus duobus pervius, lobatus
                   3 Foraminibus quinque pervius, indivisus
                   4 Foraminibus nullis pervius, indivisus