92 PROCEEDINGS COTTESWOLD CLUB 1903 
the Devonian Limestone of South Devon appears to have 
chiefly originated from Corals, Crinoids, Ostracoda, Stro- 
matoporoids, and fragments of shells, while what is known 
as the Goniatite limestone alone contains Foraminifera. 
The last of the Palzozoic limestones is that of the 
Carboniferous Limestone, so well seen in the gorge of the 
Avon, Cheddar Cliffs, and Symond’s Yat. In a paper 
which appears in the Quarterly Journal of the Geological 
Society, on the Carboniferous Limestone at Clifton, I 
adopted the classification of Professor Hull, thus :— 
Stage C.—Upper Limestones, 100 feet thick. 
Stage B.—Middle Limestones, 1,620 feet thick. 
Stage A.—Lower Limestones, including (1) Black Rock, 
430 feet thick; (2) Lower Limestone Shales, 
500 feet thick. 
Since then I have seen no reason to alter my views but 
rather to confirm the classification. Doubtless there may 
be local divisions, but for correlation generally the classi- 
fication must be broad. Taking the West of England 
and Wales there appear to have been three marked con- 
ditions in the deposition of the Carboniferous Limestone, 
which I have found to occur at Clifton, in the Forest of 
Dean, and North Wales. The first, Stage A, is the gradual 
alteration of conditions which put an end to the Old Red 
Sandstone and allowed those organisms to exist whose 
calcareous remains account for the Lower Carboniferous 
Limestones. 
During Stage A the West of England was covered by a 
shallow sea, on the floor of which there was an alternation 
of deposits. At first we find sandstones and shales pre- 
dominated, with occasional beds of impure limestone; but 
as we ascend in the series of strata the limestone becomes 
more frequent and the sandstones and shales less, till at 
last a dark, thick series of limestones are met with, built 
up chiefly of the remains of crinoids. The process I have 
