180 PROCEEDINGS OF THE GHOLOGICAL SOCIETY. (Jan. 12, 
Harptree, Chewton Mendip, Stratton on the Fosse, Mells, and Elm 
on the north side, where it is a grand and significant feature in 
the physical structure of the flanks of the Mendip chain. In the 
‘words of De la Beche, “Standing on any of the high grounds on 
the Mendip Hills, it is interesting to consider how exactly the 
masses occur as they should do, under the supposition that they 
have been beaches among islands rising above the sea of the time.” 
Again, at Croscombe, Dinder, Wookey*, Westbury, Cheddar, and 
Compton Bishop it exhibits itself as a portion of a widely spread 
series to the south of the Mendips, beneath the Keuper and Lias of 
the plain of Somerset. The singular outhers of Gambarts Hill, Wor- 
minster, Knowle, and Church Hills south-east of Wells, islands of 
Carboniferous Limestone, now surrounded by dolomitic conglome- 
rate and Red Sandstone, are evidences of what must be the deeper- 
seated condition of these beds under the plain of New Red and 
lias of Pennard.and Glastonbury on the south, onwards to South 
Devon, extending, as I believe, to, and being of the same age as, the 
conglomerate, breccia, or pebble-beds of Budleigh-Salterton, and 
the sandstones containing Hyperodapedon. 
IT cannot, also, doubt that the remarkable breccias on either side 
of the Quantock Hills and in the vales of Stogumber and Wel- 
lington, which follow the tortuous course of the flank of the Ex- 
‘moor, are all of this age. 
I must not omit to notice the remarkable outher of Broadfield 
Down, between Bristol and the Mendips ; for at no point around its 
island-like mass is it free from this encircling, reef-lke, or fringing 
conglomerate. To attest still more its widely spread condition, I 
must also assert its continuous presence at the base of the Lower 
Secondary rocks which cover up, or conceal, the coal-measures 
of the Somersetshire coal-field, or that area occupied by these rocks 
between Bristol and the Mendip Hills, in a north and south direc- 
tion, as well as east and west from Broadfield Down to Newton St. 
Leo, near Bath, thus giving an area of 140 square miles, the greater 
portion of which is, I doubt not, occupied by wneaposed dolomitic 
conglomerate, generally or universally known and designated by the 
coal-miners as the “ overlie,” or “ millstone,” from its invariably oc- 
cupying the same position below the Keuper series over the 
southern area, and covering the several members of the coal-mea- 
sures (the Upper Coal-shale, Pennant, and Lower Coal-shale). In 
the narrow vale of Wrington, at Butcombe, between Winford on 
Broadfield Down and Blagdon at the north part of the Mendip 
Hills, it is also finely exposed, the superincumbent hills of Lias 
and Red Marls being cut down or denuded so as to expose the con- 
glomerate. 
Nowhere along the eastern side of the southern basin, eacept at 
Mells, at the S.E. or EH. extremity of the Mendip range, are these 
rocks exposed or brought to the surface ; but here they conceal the 
junction of the coal-measures with the mountain-limestone abutting 
* 'The famous Hyzna-den and cavern of Wookey Hole are both excavated in 
this conglomerate. 
