92 
the lodge, traverses them for a considerable distance up the hill, and outside 
the plantation they may be traced to the base of the craggy knolls over- 
looking the road, a height from the shore of at least 150 feet. These are, 
therefore, an additional evidence of change of level of the sea-line, extending 
probably much farther back in point of time, than the beaches at Woodspring. 
Similarly, there are the remains of ancient Dunes above the raised beach 
at Birnbeck Cove, which beach, from its height above the sea, may probably 
have been contemporary with those at W oodspring. 
Another hill to which I referred in my former paper, namely Brean Down, 
exhibits, on its northern side, facing Weston Bay, at least two tiers of sandy 
accumulations, at heights ranging" with some of the terraces in Sand Bay ; of 
which the upper appears to be pure sand, and the lower to contain a large 
proportion of angular fragmentfi of limestone. So far as appears there are 
no remains of an actual beach on this range of hill. 
We have therefore, so far as observation has at present extended, alter- 
ation of relative level of land and sea illustrated very distinctly in these three 
hills and in one of the intervening bays, with these varying characteristics. 
At Woodspring we have ancient Beaches without Dunes, and at Sand Bay 
and Brean Down we have Dunes without Beaches, and at Birnbeck Cove we 
have both the Beach and the Dunes. 
Sea-washed Rocks. — It is worthy of remark that some of the rocks about 
on a level with the highest of the sand ridges on Worie Hill, are pierced by 
those peculiar holes, whether made by boring mollusca or otherwise, which 
one sees everywhere upon sea- washed rocks. 
There are also many examples of groves and striations very similar to those 
made by the mechanical action of the waves upon a rocky shore, but which 
would seem with greater probability to be due to the solvent power of sea- 
water, eroding the softer lamina 3 of the stone, and leaving the harder portions 
as ridges on the surface. 
Parallel Terraces. — From our last illustration of change of level, let us 
pass to the south-eastern part of our district, and examine the singular 
isolated Iiili of Brent Knoll. Standing in the midst of the extensive flats of 
moors which reach from the foot of the Mendip to the Bristol Channel, about 
Burnham on the west, and to beyond Bridgwater on the south, it is, from its 
elevation and peculiar form, a conspicuous landmark from all the surrounding- 
country. Its height is about 500 feet above the sea, or in other words, above 
the plain, which is little if at all higher than the sea-level. Its form is that 
of an irregular truncated cone, standing upon the edge of the flat top of a 
larger one ; so that the descent is continuous on the eastern side, but inter- 
rupted by an extensive terrace or steppe on the western. 
The hill is of Middle Lias, capped with a thin bed of Inferior Oolite. 
Whether there are any portions of Upper or Lower Lias I cannot say, but 
