THE CARBONIFEROUS SYSTKM 309 



anticlinal folds seen in the coast-sections being faulted at the crest 

 and sometimes overthrust. The sandstones are hard, of grey, lilac 

 or brownish tints, and usually from 4 to 5 feet thick, but some- 

 times less ; the shales and mudstones are grey or red. These strata 

 include beds of hard impure coal, generally known as culm, and 

 there are also thin unpersistent beds of limestone as well as layers 

 of calcareous nodules. 



The nodules near Bideford and Instow have yielded marine 

 shells chiefly of Gastrioceras carbonarium, G. Listeri, Dimorphoceras 

 Gilbertsoniy Pterinopecten papyraceus, and Posidoniella lewis ; and 

 of this assemblage Dr. W. Hind remarks that it resembles that of 

 the Bullion Mine seam in the Lower Coal-measures of Lancashire. In 

 the same district plant remains have been collected by Mr. T. Rogers 

 ami Mr. N. Arber, and the latter has shown that the flora is that 

 of the Middle, not of the Lower Coal-measures, so that here, as in the 

 Bristol area, there is a conflict between the evidence of the fauna 

 and the flora. Nothing to indicate the presence of Transition 

 or true Upper Measures has yet been found in Devonshire. 



In the southern part of the area near Chudleigh and Newton 

 Abbot the base of the Westphalian Series is a conglomerate which 

 lies unconformably on the chert-beds of the Lower Series and in 

 some places appears to overstep them on to the Devonian rocks. It 

 contains pebbles of chert and limestone and a few of granite, which, 

 however, is not like that of Dartmoor. This bed is overlain by a 

 set of alternating grits and shales like those of Bideford, and near 

 Exeter Mr. T. G. Collins has recently obtained fossils which show 

 that they occupy a low position in the series. 



D. CONTINENTAL EQUIVALENTS 

 1. Westphalia 



We take this area first because the succession of beds therein 

 found is regarded on the continent as the typical development of 

 the series. De Lapparent has well remarked the area might be 

 appropriately called the basin of Miinster, since that city overlies 

 the central portion of it It is only in the southern part of the 

 basin that the Carboniferous rocks come to the surface, the greater 

 part being concealed beneath the Jurassic and Cretaceous strata 

 which form the Westphalian plain. The surface tract extends 

 from near Dusseldorf on the Rhine, by Hagen and Arnsberg to 

 Brilon and Marsburg, a distance of about 90 miles. From this 

 outcrop the beds dip northwards and then extend in a series of 

 undulations beneath the great plain, probably reaching as far as the 



