Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       Astra Plinius - celestial bodies
         Universe
           (Supercluster) Virgo-Hydra-Centaurus Supercluster
             (Supercluster) Virgo Supercluster
               (Cluster) Local Group
                 (Galaxy) Milky Way Galaxy veter.
                   (Spiral arm) Orion Arm
                     (Region) Local Bubble
                       Local Interstellar Cloud
                         (Planetary system) Solar System
                           (Planet-satellite system) Earth System
                             (Planet) Earth veter.
                               "spheres" (Earth)
                                 (Sphere) Biosphere (Earth) - zone of life
                                   "marine ecoregions"
                                     (Biogeographic realm) Arctic
                                       01 (Marine ecoregion) North Greenland
                                       02 (Marine ecoregion) North and East Iceland
                                       03 (Marine ecoregion) East Greenland Shelf
                                       04 (Marine ecoregion) West Greenland Shelf
                                       05 (Marine ecoregion) Northern Grand Banks–Southern Labrador
                                       06 (Marine ecoregion) Northern Labrador
                                       07 (Marine ecoregion) Baffin Bay–Davis Strait
                                       08 (Marine ecoregion) Hudson Complex
                                       09 (Marine ecoregion) Lancaster Sound
                                       10 (Marine ecoregion) High Arctic Archipelago
                                       11 (Marine ecoregion) Beaufort–Amundsen–Viscount Melville–Queen Maud
                                       12 (Marine ecoregion) Beaufort Sea—continental coast and shelf
                                       13 (Marine ecoregion) Chukchi Sea
                                       14 (Marine ecoregion) Eastern Bering Sea
                                       15 (Marine ecoregion) East Siberian Sea
                                       16 (Marine ecoregion) Laptev Sea
                                       17 (Marine ecoregion) Kara Sea
                                       18 (Marine ecoregion) North and East Barents Sea
                                       19 (Marine ecoregion) White Sea