217 
There is no positive evidence as to what the upper bed is; 
but, as far as I can now judge, it was the top of the Buckland 
beds, or the lower beds of the Turnert zone. 
The beds of the Lower Lias above are difficult to trace, but 
at Brookthorpe, four miles from Gloucester, at an elevation of 
150 feet above the boring, the lower bed of the Middle Lias 
occurs. 
_ I think we may, therefore, assume that the depth of the 
Lower Lias is about 550 feet. 
Mr Hout, in his memoir of Sheet 44, states that under 
Cheltenham the Lower Lias is supposed to be 600 feet; but 
does not give any information as to how the thickness is 
arrived at; and that southward, towards Bristol, the thickness 
is only 300 to 400 feet. 
The boring has, I believe, added much to our knowledge of 
the Lower Lias in this neighbourhood, and which will be of 
advantage to future observers. 
‘Now it may not unnaturally be asked, How it was that Dr 
_ Wricut and myself were unable to determine the position of 
the beds long before the boring ceased, and so have saved 
_ Messrs Rozertson considerable expense ? 
To this I would remark that there is always much difficulty 
in ascertaining where shells come from in a boring, more 
j particularly when only a small-sized augur is used. 
__—*‘The pieces of Gryphea we thought might have fallen in 
_ from the beds above, and we felt justified in thinking such was 
_ the case, as the character of the small shells brought up in the 
core shewed so marked a resemblance to those occurring in the 
_ Avicula contorta series, and which probably have a wider range 
than is generally supposed. 
__. The moral, perhaps, to be drawn is this :—That whenever 
you are near to a great line of disturbance which, in this case, 
Professor Parxures was of opinion extended for 120 miles, from 
Flintshire into Somersetshire, and probably at least the major 
part took place at the close of the Permian; and as there is 
“unquestionable evidence of a considerable upheaval occurring 
after the Lias was deposited, as is shown at Purton, the greatest 
Q 
