The Carboniferous Succession below the Coal-Measures. 455 



4. The actual Sequence as now BSTABLisnED. 



The chief result of our exaiTiination of this area of development of 

 Carboniferous rocks is the discovery that the sequence is normal, in 

 every respect, to that observed throughout the North Midlands. 

 The structure of the country is fairly indicated by its topographical 

 features, and the succession of the chief divisions of the Carboniferous 

 system is not obscured or complicated by the varioud faults that 

 traverse the district. Both the paJEeontological and lithological 

 sequence agree most remarkably with that ah-eady established for the 

 area of the southern portion of the Pennine Cliain, as will be seen from 

 the following diagram (Fig. 2) of the succession in North Wales : — 



General 

 Nomenclature. 



Local 

 Nomenclature. 



Mining 

 Classification. 



Coal-measures. 



Gwespyr 

 Sandstone. 



Holywell Shales. 



Teilia Beds, or 

 Chert in places. 



Cherts and 



Calcareous Grits 



in places. 



Aberdo 

 Limestone 



Grey Limestone. 



White 

 Limestone. 



Brown 

 Limestone. 



Coal- 

 measures. 



Watertight 

 > barrier. 



Lead- 

 measures. 



Abundant and Characteristic 

 P'ossiLs, etc. 



ICoal-seams. 



Calamites, Stigmaria, etc. 

 Posidoniella Iccvis \ 



Fossiliferous Pterinopecten 



bullions I papyracem. 



Posidonomya Becheri 

 P. membranacea 



Proditctiis longispinus. 



P. giganteus. 



Lonsd't leinjloriformis . [Cyathacconia 



beds.) 

 Lithostrotion irregulare 

 L. junceiim 

 L. Portlocki 



Spirifer triangnlnris. 

 (Abundant. 

 S. trigonalis. ,, 



Amplexi- 

 zaphrentis 



Lithostrotion Martini. 



Productus Cora. (Abundant.) 



C/ionete.s papilionacea. 

 (Abundant.) 

 Cyathophyllum Murchisoni. 



Seminuhi jicoxdcs. 

 Daviesielta Llangollensis. 



Note. — This diagram, Fig. 2, is not to scale. 



