PI. 57. 
t'ig. I. 
Lower 
Purbcck 
beds, 
Lurrstone. 
P'lrt bed, 
black movld, 
<ind pebbles. 
Portland 
stone. 
.'alcareous slate 
of fresh water 
formation. 
Temporary 
dry land. 
Marine 
formation. 
Section of the Dirt-bed in the Isle of Portland, shewing the subterranean remains 
of an ancient Forest, De la Beche. 
P‘g, 2 . 
Circular ridges and depressions on the Burrstone, in the J. of Portland, round an erect 
stump of a tree, four feet high. Sketched by Professor Henslow, 1832 . 
Fig. 3 . 
Lower Purbcck beds 
composed of calcare- 
ous ,<tlat€offrcshwalcr 
formation. 
Soft burrstone. 
Ancient forest in the 
dirt bed. 
Portland stone of 
marine formation. 
Section (fthe Cliff east ,f LulwoHh Cove, Dorset. 
Buckh/nd. 
