Hind : Carhoniferoits Geology. 



247 



though interfering largel}'^ with the deposition of Visean rocks, 

 did not wholly prevent the establishment of a Visean fauna 

 in that area. 



It is argued that the latter series cannot be below the 

 Posidonomya Cherts, because there is not room for them between 

 the Devonian Diabase and the cherts, but it is forgotten that 

 the lowest Culm fauna, i.e., the Erdbach Breitscheid or Prole- 

 canites compressus fauna, which is admitted to be below the 

 Posidonomya beds, is absent, and that consequently the lowest 

 member of the sequence is absent at Konigsberg. 



Now the Visean fauna of Konigsberg is that which is always 

 found to immediate^ precede the Prolecanites compressus 

 beds, and would only be a few feet below it, and I should expect 

 to find indications of both faunas in the same locality. The 

 question is one therefore that could only be settled by an 

 appeal to palaeontology in such a disturbed area, especially 

 when volcanic activity played a large part in conditioning the 

 deposition of the series. 



Two points are of interest, i.e., first, the question of the 

 relation of the Upper Devonian beds to the Culm is identical for 

 Devonshire and Germany, and I think that the key to this 

 question will be found in Belgium ; second, that the closing of 

 Dihunophyllum times, and the ushering in of the Pendleside 

 type was accomplished in Great Britain with much volcanic 

 interference both in the Midlands and South Devonshire. 



THE MILLSTONE GRIT. 



The Millstone Grit requires very careful study at the present 

 time. The series, when present in force, is very easily recog- 

 nised, and offers fine features with its weathered crags, and its 

 shale valleys and doughs. But the unfortunate character 

 of the whole series is its extremely local development. It is 

 known that in Belgium its representative, the Gres grossier 

 of Andenne, is only 12 metres thick ; that in the West of 

 Ireland the series is about 300 feet, and in Scotland 687 

 feet, mostly shales ; while in Lancashire the whole series is 

 very rapidly expanded into more than 3000 feet. The local 

 variation in thickness of the series is well seen in North Stafford- 

 shire, where the Grits on the Cheshire border at Mottram are 

 2700 feet thick, but in the course of 20 miles south, the whole 

 series is only represented by 300 feet of Grits and Shales. 



North of Settle, where no representatives of the Pendleside 



1909 July I. 



