AGE OF THE LIGNITIC DETERMINED BY ITS FLORA. 



343 



plants of this last locality, if not a distinct Cretaceous flora, at least a num- 

 ber of representatives of the types of the Dakota group. 



The thirty species recognized in the specimens of Point of Rocks have 

 been described above; but the deduction derivable from the determination of 

 these plants in regard to evidence of geological age will be more clearly under- 

 stood by a comparative table pointing out the atfinity or identity of characters 

 with species of other localities. The points of comparison are indicated with 

 the flora of the European and of the Arctic Miocene, of the Canadian Ter- 

 tiary, of the European Eocene, of Golden, Black Buttes, and the Cretaceous 

 in general. 



Table indicating the relation of the fossil plants of Point of Rocks. 



[An. signifies analogous \ Id., identical.] 



