Lower [ '^ '^ — — ^ '_-" '^ "; .*> _ =»«=-»-,.-* 



Purbeck f -X-^-^ , , — , — ^ -. — ^^ — - — .  —  



6 -^ i - J 



^ 



Burrstone. 



Temporary 

 dry land. 



PL 57. 



Calcareous slate 

 of fresh water 

 formation. 



Section of the Dirt-bed in the Isle of Portland, shewing the subterranean remains 

 of an ancient Forest. JDe la Beche. 



: Fig. 2. 



■^F^^, 



Circular ridges and depressions on the Burrstoney in the I. of Portland, round an erect 

 stump of a tree, four feet high. Sketched by Professor HenslozOj 1832. 



Fig. 3. 



Lower Purbeck beds 

 composed of calcare- 

 ous slate of freshwater 

 formation. 



Soft burrstone. 



Ancient forest in the 

 dirt bed. 



Portland stone of 

 marine formation. 



Section of the Cliff east of Lulworth Cove, Dorset. Buckland. 



