171 
that measurement considerably ; while at the Hamlet of Meadgate 
or Medycat, seven miles S.E. of Bath, it cannot be estimated at more 
than from 40 to 70 feet, and may very possibly be less. 
The presence of the ‘‘ Middle Lias,”’ or ‘‘ Lias Marlstone,” is one 
of the points most difficult of identification in the Bath district, and 
I must acknowledge, that during the few opportunities I had of 
studying the question, I was unable to satisfy myself of the presence 
of that deposit by any recognisable features. I am bound, however, 
to add that Mr. Moore has satisfied himself of its existence, though 
in an obscure form, and under altered conditions from those in which 
it presents itself in the Cotteswold range. At Charlcombe Hill, as 
well as on the north-western extremity of Dundry Hill, a consider- 
able thickness of very adhesive ferruginous clay appear to occupy 
the position of the ‘‘ Middle Lias,” and may very possibly be its 
representative ; but if so, its presence is not indicated by any fossils, 
in so far as I was able to discover, and at Meadgate the Upper and 
Lower Lias Maris appear to pass insensibly into one another, 
without any distinct line of demarcation, though the presence. of 
‘‘ Spirifer rostratus’’ about the middle of the series would appear 
to mark the horizon of the ‘‘ Marlstone.” Lonsdale, in his Memoir, 
speaks of the ‘‘Marlstone” near Bath as containing numerous in- 
dividuals of ‘‘a large Pecten with obtuse ribs,” which might be 
attributed to P. equwalvis ; but, inasmuch as he appropriates the 
term ‘‘ Marlstone”’ to certain sandy beds, interposed between the 
Lias and the Inferior Oolite, it is plain that he refers to the ‘‘ Sands” 
interculated between these two deposits; in which, however, I was 
not fortunate enough to observe the Pecten in question, nor any 
other fossil organism whatever. These ‘‘Sands” are everywhere 
present in situ, and exhibit a series of alternating Sands and Sand- 
stones to a thickness of from 60 to 80 feet, to which extent they are 
exposed at Charlecombe, the only spot at which I was able to trace 
them throughout their entire thickness, and as this Section presents 
some features of interest, I will proceed to review it in detail. 
SECTION AT CHARLCOMBE,. 
It will be seen by reference to the map, that the village of Charl- 
combe lies due north of Bath, niched into the hollow of one of the 
numerous pretty combes scooped out by the action of the retiring 
waters, when the coast-line, of which it forms a part, was slowly 
emerging from the waves of the ancient ‘‘tertiary” ocean. The 
direction of the Valley itself is about N.W. and S.E., and is traversed 
throughout the greater portion of its length by a small rivulet, which 
takes its rise in'a deep gully, not far from the Church, and it is this 
gully which affords the Section to which I have adverted. 
After passing over the entire thickness of the Lias Clays, which 
at this point I cannot estimate at less than 600 or 700 feet, the 
gully intersects the highest beds of the Upper Lias Shales, which are 
here seen dipping downwards at a considerable angle, the result 
