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of South Wales, once of greater extension, and that its preser- 
vation is mainly due to its having remained in a finally depressed 
condition in the form of a basin, and the eroding effects were 
reduced to a minimum. 
It is an accepted fact that the Forest of Dean Mineral 
Basin was originally joined to that of Bristol and South Wales, 
and probably to other areas which extended to and beyond 
Gloucester. 
Tt ig not necessary at this moment to search for evidence, 
neither can it be attempted, in detail, but a few references can 
be made, in passing, bearing directly upon this question. 
_ Professor Etheridge has shown that the Carboniferous Lime- 
stone exists at the base of his celebrated section of the Trias, 
Rheetic, and White Lias at Aust Passage, but the Permian, 
about 300 feet thick, the coal measures, and the Millstone Grit, 
which should be found to intervene between the Trias and 
Carboniferous Limestone, are absent, the New Red Sandstone 
being, in fact, in contact with the Carboniferous Limestone. 
The Keuper marls of the Trias are again visible in the re- 
markable section at Garden Cliff, Westbury-on-Severn, and there 
the Rhetic, being capped from the upper portion with thin beds 
of White Lias, which latter probably extends under Gloucester. 
Vestiges of Permian rocks have been discovered at the Malvern 
Hills, and also at May Hill. 
A portion of the New Red Sandstone is also to be found in 
the neighbourhood of Flaxley, deposited unconformably against 
intruded Silurian; consequently we have inferential evidence 
at least, that these measures extended over the Forest of Dean 
and far beyond. The Keuper and Rheetic beds incline in a 
South-Eastern direction from Garden Cliff, and ata very low 
angle of from two to three degrees, so that there ought to be a 
correspondence between the strata, or at least some portion of 
it, on both sides of the river Severn, and therefore if we place 
all the strata in an imaginary sense, conformably one above 
another, we could realize the depression and denudation they 
have undergone. 
