20 
outcrop of this rock again occupies a considerable surface of ploughed land, extending from 
Penselwood through the vale of Blackmoor to Stourminster Newton. 
The greatest surface of this stony land is about Caine, by Bremhill, Lyneham, and Token- 
ham, to Wotton Basset ; thence by Lydiard, Blunsdon, Stanton, Stratton, and Seven- 
hampton, to Highworth ; Coleshill, Shrivenham, &c. to Faringdon, and thence by the great 
road to Oxford, and spreading eastward, almost to Abingdon, where it is covered with gravel. 
Over the Thames it again expands from Sandford, westward by Cowley, Heddington 
Common, and all the elevated plain between the foot of Shotover Hill and Oxford, to Stanton 
St. John’s, &c. contracting in the width of its course northward, till it becomes indistinct in the 
great breadth of clay land. 
The sand which lies beneath this rock is scarcely known in some places ; in others it occupies 
a great breadth of surface, and in others is highly tinged with the red oxyd of Iron, which 
gives it a very different appearance. 
Between the limestone rocks, containing the Fossils herein described, and the sand beneath, 
lies a floor of stone, which preserves the escarpment of the stony ridge, by which the great 
clay vale district might be said to be divided into two ranges of vales ; the vales of White- 
Horse and Aylesbury being to the east, and the vales of Bedford, Ottmoor, Isis, and Avon or 
north Wilts to the west of this ridge. 
ORGANIZED FOSSILS. 
fig. 
1 Madrepora - Stanton near Highworth. Shippon. Bagley Wood 
Pit. Banner’s Ash. Well near Swindon, Wilts 
and Berks Canal. Steeple Ashton. South of 
Bayford. 
2 Madrepora - - - Steeple Ashton. 
3 Madrepora - Steeple Ashton. Longleat Park. Stratton. Wot- 
ton Basset. Banner’s Ash. Well near Swindon, 
Wilts and Berks Canal. Shippon. Bagley 
Wood Pit. Stanton. Ensham Bridge. 
FIG. 
1 Turbo 
2 Ampullaria 
3 Melania striata 
4 Ostrea crista galli 
5 Cidaris 
6 Clypeus 
Longleat Park. Derry Hill. Steeple Ashton. 
Banner’s Ash. Wotton Basset. Bagley Wood 
Pit. 
Longleat Park. Marcham. Kennington. Silton 
Farm. South of Bayford. Hinton Waldrish. 
Caine. Steeple Ashton. Silton Farm. Banner’s 
Ash. Well near Swindon, Wilts and Berks 
Canal. South of Bayford. 
Derry Hill. Shotover Hill. Westbrook. Long- 
leat Park. South of Bayford. Wotton Basset. 
Hilmarton. Well near Swindon, Wilts and Berks 
Canal. 
Meggot’s Mill, Coleshill. Longleat Park. Hin- 
ton Waldrish. 
This latter specimen, as shown in my Stratigraphical Table of Echini” is one of the cha- 
racteristic distinctions of the Pisolite part of the rock. 
