Quart. Jourr. Geol. Soc. Yol. LXXVIII. p]. 



INDEX. 

 Nant-y-Bache Group 



° 'o° »oo 3°o 400 so o Yafd s 



Clyn-Dyfrdv/y Group ; ^,,3^^ Ouarrv ' \'^^' ^"^ 



& Pen-y-Glog- Slates " ^ ^ —^ c- ••••— —^ 



Slates & 

 Sandstones 



Pentre-Dwfr 

 Slates 



Slates & Sand- 

 stones 



Pen-y-Glog 

 Slates 



UPPER VALENTIAN 



Crenulatus Beds 



Purple Slates 



Pale Slates 



Lower Llandovery 



The shaded areas 

 represent the steep 

 limbs of the folds. 



Mvi> OV TllK Alti:.^ UOL'.ND :\r()KI.-Vl AEN, ILM STRATI Nti THE St Kin IRE OF TIIK 

 XORTUEHX LiMIS OF THE Ll.AXtiOI.l-E.N SyNII.INOKII M. 



