PROCEEDINGS OE THE COTTESWOLD CLUB 33 



I now pass to the Carboniferous Epoch. The calcareous 

 de[)Osits in the sea of this period are represented by the 

 Carboniferous Limestone, of which the well known clifls in 

 Derbyshire, at Clifton in Gloucestershire, Cheddar in 

 Somersetshire, and a great portion of the hills near Khyl 

 in North Wales are instances. 



That moUusca, corals, crinoids, polyzoa, etc., were 

 plentiful in the sea of this period is well known, but it is 

 erroneous to suppose the remains of the shells and 

 skeletons of these creatures were the chief contributors 

 to the calcareous deposits which accumulated on the 

 floor of the Carboniferous sea. 



In certain beds of this series, remains of moUusca 

 and coral debris became doubtless the chief factors, but if 

 we take the great central mass, which at Clifton is 1620 

 feet thick, we shall find that microscopic life has in the 

 main contributed the material of which the limestone has 

 been built up. 



Indeed microscopic life must have been quite as 

 abundant in Carboniferous days as it was in the sea in 

 which the chalk formation took place, and in parts of the 

 ocean of to-day. We know that the white chalk is largely 

 made up of the shells of foraminifera, and that the 

 calcareous ooze dredged up by the "Challenger" was also 

 largely made up of these minute shells, together with the 

 remains of certain other low forms of life, including 

 siliceous ones. 



It is, of course, deeply interesting to know of the 

 existence of these deposits, both at the present time, and 

 during that of the period in wdiich the white chalk was 

 gradually formed. This interest, too, is increased when 

 we know that a very similar condition of things existed m 

 the still earlier Pahcozoic days of the Carboniferous Lime- 

 stone, a fact which is strictly consistent with the teaching 

 of Button. 



