244 LOWER OOLITIC HOCKS OF ENGLAND : 
purposes other than " marling," and rarely on this account. Traces 
of clay and earthy limestone were exposed in the valley of the 
Broadmead Brook, north of Marshfield ; and clays were exposed 
here and there to the south-east of Horton. The presence of the 
formation is indicated by springs and marshy ground. 
A number of fossils have been collected from the formation 
near Cubberley, a few miles south of Cheltenham ;* but as a rule 
not many fossils have been obtained from the formation in 
Gloucestershire. Near Stroud and Minchinhampton, Ostrea 
acuminata occurs in the clays and bands of earthy limestone. 
The beds were proved in the Sapperton railway-tunnel, and the 
thickness was estimated at 70 feet. Here Ostrea subrugulosa, 
Homomya Vezelayi, Myacites calceiformis, Ceromya plicata, 
Avicula echinata, Pecten vagans, Sphcera Madridi, Area lota, and 
Rhynchonella concinna have been obtained. f 
The following section was made by E. Witchell from a trial- 
shaft sunk on Stroud Hill : 
FT. IN. 
"Bands of sandstone alternating with clay, 
and beds formed of the valves of Ostrea 
acuminata - - - - -150 
Yellowish-brown marl and shale, with 
Fullonian 
several thin bands composed of 0. 
(Fuller's Earth). ^ acuminata ; passing downwards into blue 
and buff laminated shale - - - 30 
Blue marly clay and shale, the lower portion 
partly consolidated, and, when dry from 
exposure, having a conchoidal fracture - 25 
Inferior Oolite. 
In the shaly beds, Witchell obtained specimens of Lima duplicata, 
Posidonomya opalina, Trigonia PPitchelli, T. imbricata, and 
remains of Crustacea belonging to the genas Magita ; as well as 
numerous specimens of Glyphea pseudoscyllarus. From the 
upper beds he procured, in addition to Pecten vagans, Placunopsis 
socialis, and Ammonites gracilis, forms that characterize the 
Stonesfield Slate of the neighbourhood : but (as he remarks) the 
upper beds pass into the Stonesfield Slate. 
Witchell also noted the presence of Fuller's Earth at White 
Hill, near Stroud. It occurred as an isolated mass, in a depres- 
sion of the Inferior Oolite ; and a well had been sunk in it to 
the depth of 35 feet. The clay must originally have sunk or 
slipped from higher ground into a fissure, in the Inferior Oolite, 
of considerable width and depth. 
With regard to the Fuller's Earth near Minchinhampton, 
Lycett observed that its thickness varies from 60 to 80 feet. 
Northwards in the parish of Bisley, " it rapidly thins out, and 
at Througham and Lypiatt, where the Stonesfield Slate in 
mass begins to occupy its position, the thickness is reduced 
to about 9 or 10 feet. It consists of stratified blue and 
* Hull Geol. Cheltenham, p. 52. 
f Lycett, Cotteswold Hills, p. 89. 
J Geology of Stroud, p. 69 ; Proc. Cottesw. Club, vol. vi. p. 144, vol. vii. p. 117, 
