EXPLANATION OF THE PLATES. 
279 
Fig. 2. Sectional view of the coast of Devonshire, from Sidmouth 
to Beer-head. The first comb or dry valley, on the east of Sidmouth, 
is abruptly truncated, like those represented in fig. 1; the others 
terminate by a gradual slope towards the sea. The line of junction of 
the green-sand with the red marl is marked by the cessation of in¬ 
closures and of fertile soil, exactly at the point where the green-sand 
begins. The table-lands, that form the summits of these green-sand 
hills, are for the most part barren heaths, except where they are 
covered with diluvian gravel, or by a bed of unrolled chalk flints. 
This observation applies also to the green-sand summits in fig. 1, and 
to the table-lands composed of the same stratum, which stretch in¬ 
land from the coast to the flat summits of the Black Down Hills, in 
which this formation attains its highest elevation, overhanging with 
its escarpment the vale of Taunton. (See map at Plate XXVI.) 
Plate XXVI. 
Map of the valleys which intersect the coast of Dorset and 
Devon.—The north-west angle, not being mentioned in the paper, is 
not coloured. 
Plate XXVII. 
Map showing the manner in which the Lickey sand-stone pebbles 
have been drifted from Warwickshire, through two low points in the 
escarpment of the oolite limestone at Moreton in Mnrsh, and on the 
north of Banbury; and been spread oyer the country along the valleys 
of the Evenlode, the Cherwell, and the Thames, and also on the north 
of Buckingham. 
