92 



Jurassic formation. Prof. Dana places it (the Wealden) as a separate 

 epoch, intermediate between the Oolitic and Cretaceous periods, but as 

 has been before remarked, it should rather be coi-reiafed with one of the 

 marine deposits of the Cretaceoiis or Jurassic. 



At jDresent it would be premature to express any very decided opinion 

 on the exact age of these Coal-bearing rocks. All that the fossils show 

 with any degree of probabilit}^ is that the series can scarcely be much 

 newer than the Middle Cretaceous, or older than the Upper Jurassic. 



