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 Amphibia Linnaeus, 1758 - amphibians see Class Amphibia Gray, 1825
           Order Serpentes Linnaeus, 1758 see Suborder Serpentes Linnaeus, 1758
             Genus Crotalus Linnaeus, 1758
               192 Crotalus horridus Linnaeus, 1758 - timber rattlesnake
               195 Crotalus dryinas Linnaeus, 1758
               196 Crotalus durissus Linnaeus, 1758 - Aruba Island rattlesnake