Natura - nature
Ref: C. Linnaeus, 1748: 210
   actualia - actual entities
  Ref: A. Voltolini, 2006: 44 (note 19) [assumed position]
     Mundus Plinius - physical world
    Ref: C. Linnaeus, 1758: 5 [indirect position]; 24 Apr 2014.
       Astra Plinius - celestial bodies
      Ref: C. Linnaeus, 1758: 6
         Universe
        Ref: R. Powell, 2006: 13 Dec 2007 [indirect position]
           (Supercluster) Virgo-Hydra-Centaurus Supercluster
          Ref: R. Powell, 2006: 3 Nov 2010
             (Supercluster) Virgo Supercluster
            Ref: R. Powell, 2006: 3 Nov 2010
               (Cluster) Local Group
              Ref: R. Powell, 2006: 13 Dec 2007
                 (Galaxy) Milky Way Galaxy veter.
                Ref: R. Powell, 2006: 13 Dec 2007
                   (Spiral arm) Orion Arm
                  Ref: R. Powell, 2006: 13 Dec 2007
                     (Region) Local Bubble
                    Ref: Wikimedia: 5 Oct 2013
                       Local Interstellar Cloud
                      Ref: Wikimedia: 5 Jun 2013
                         (Planetary system) Solar System
                        Ref: R. Powell, 2006: 13 Dec 2007
                           (Planet-satellite system) Earth System
                          Ref: IAU, WGPSN: 12 Dec 2007
                             (Planet) Earth veter.
                            Ref: IAU, WGPSN: 12 Dec 2007
                               "spheres" (Earth)
                              Ref: 23 Jul 2010
                                 (Sphere) Biosphere (Earth) - zone of life
                                Ref: Wikimedia: 23 Jul 2010
                                   "terrestrial and freshwater ecoregions"
                                  
                                     (Bioregion) New World
                                    Ref: Wikimedia: 9 Jul 2013
                                       (Biogeographic realm) Nearctic
                                      Ref: D.M. Olson et al., 2001: fig. 1
                                         "terrestrial ecoregions" (Nearctic)
                                        Ref: WWF, present: 27 Apr 2011
                                           (Terrestrial ecoregion) Middle Atlantic coastal forests (Nearctic)
                                          Ref: WWF, present: 29 Jul 2010
                                             "United States" (Middle Atlantic coastal forests)
                                            Ref: WWF, present: 21 Apr 2011
                                               "Delaware" (United States; Middle Atlantic coastal forests)
                                              Ref: WWF, present: 21 Apr 2011