ROCKS OF THE FOREST OF DEAN. 217 



in the question of correlation there were not only the difficulties 

 mentioned by the last speaker, but further the Calciferous Sand- 

 stone of Scotland represented a large part of the true Carboniferous 

 Limestone of England. The Yoredale series also represented a part 

 of the Carboniferous Limestone series. 



Mr. De Bance also objected to the correlation. As regards the 

 Yoredale beds, though present in Derbyshire they are absent in 

 North Wales and around the Shropshire coalfield. The Millstone 

 Grit, when traced S.S.W., thins out, and is missing in North 

 Wales in one area. Going further south, the Millstone Grit comes in 

 again ; but the Yoredale rocks do not. The name Yoredale was to 

 be regretted ; for the Yoredale limestones of the typical valley of 

 the Yore are really true Carboniferous Limestone, and correspond 

 palseontologically and physically with it. 



Mr. Wethered, in reply, said that, if the beds in the Forest of 

 Dean occupied the position of the Calciferous Sandstones of Scotland, 

 the probability was that they corresponded with them in point of 

 time. The palaeontological argument also seemed contradictory ; for 

 Mr. Etheridge said the Calciferous Sandstone had only two fossils, 

 but Mr. Topley asserted there were plenty. As for Mr. De Ranee's 

 arguments, he did not see that lithological similarity could be ex- 

 pected in the northern Yoredales and in these southern rocks. 

 Even in the latter region the same series underwent a change in a 

 comparatively short distance. All he said was that they differed 

 from the Millstone Grit and were in the position of the northern 

 Yoredales. 



