REPORT OF THE CHIEF ASTRONOMER 829 



SESSIONAL PAPER No. 25a 



Porcupine creek and Great valley, all of which are Lower Eocene. To this we 

 may add the Eocene of the North Polar regions, the floras of which are Eort 

 Union, as already shown. On the other hand, the Green River group furnishes 

 a correct index of the Upper Eocene or Oligocene floras. Erom these fixed 

 data it may be possible to establish the proper correlation of the unknown 

 horizons. 



