208 PROCEEDINGS COTTESWOLD CLUB 1909 
of Minchinhampton—barely eight miles away—is so familiarly associ- 
ated. Above the Great Oolite, and flooring the greater portion of 
the upland, is the Forest Marble, with a clay-bed at its top, and 
occasionally a representative of the Bradford Clay at its base. They 
would understand that these clay-beds were also of considerable im- 
portance, and constituted the main factor in the origin of many of the 
‘‘]and-springs ” of the district. Above the Forest Marble beds is the 
Cornbrash—a name that is self-explanatory. The Cornbrash is about 
14 feet thick in the neighbourhood of Kemble, and is succeeded by the 
Callovian with its usually prominent bed of Kellaway’s Rock.* A 
noticeable rise in the ground and the growth of gorse-bushes generally 
readily indicate where the sandy Kellaway’s Rock occurs; while 
correlated with the change from the predominantly stony lands of 
the Great-Oolite Series to the essentially clay-lands of the Oxfordian 
is a change in the flora and in the methods of separating the fields; 
in the former case stone walls are the rule, and in the latter, hedges. 
Much of the clay-ground of the Oxfordian is covered with a thick 
deposit of rolled gravel, and around South Cerney pits are numerous. 
Near South Cerney the ridge formed by the outcrop of the 
Kellaway’s Rock has been cut through for the railway, and at the 
time of construction a most instructive section was revealed—huge 
doggers of Kellaway’s Rock occurring amid sand. The section is 
still well worth a visit, as recent excavations have been made in the 
sides of the cutting. Prof. Harker gave a detailed description of the 
cutting, and Mr H. B. Woodward and Mr Rhodes added some more 
records to the list of fossils. Mr Richardson has found in addition a 
Gervillia, Turbo sulcostomus, Phillips, and Glyphea sp. 
Dealing next with the section the Members were facing, it was 
stated that it showed the brown friable loam that forms the base of 
the Callovian, the Cornbrash rocks (14 feet thick,) and formerly the 
upper clay-bed of the Forest-Marble subdivision. ; 
The presence of the Cornbrash and the basal Callovian deposits 
is not shown on the Geological Survey-Map, because they were not 
detected at the time it was made.” 
The Cornbrash rocks are very fossiliferous, containing in abun- 
dance various forms of Ornithella obovata (Sow.) It is important to 
notice which brachiopod it is that is common in a section of Cornbrash 
rocks, its position with regard to the other members of the same 
class, and their relative abundance, as such facts will form the basis 
of more minute correlation of the deposit that is dated as disci on the 
ammonite evidence. 
1 The term “Callovian” is used in the recently-issued Guide to the Fossil 
Invertebrate Annals, etc., Brit. Mus., as synonymous with the term “ Kellaway’s Rock,” 
and the term “ Oxfordian ” with “ Oxford Clay.” A. Harker, Proc. Cotteswold Nat F.C., 
vol. viii., pt. 2 (for 1883-84), p. 176-187. 
H. B. Woodward, “The Jurassic Rocks of Britain—The Middle and Upper Oolitic 
Rocks of England (Yorkshire excepted),” vol. v, (1895), p. 34, Mem. Geol. Surv. 
2 See H. B. Woodward, “ Jurassic Rocks of Britain—The Lower Oolitic Rocks of 
England (Yorkshire excepted),” vol. iv, (1894), p. 442, Mem. Geol. Surv. 
