30 DB- STAMP AND ME. WOOLDEIDGE OK THE [vol. lxxix, 



series of Upper G-lenkiln-Lower Hartfell (Bala) age. The former 

 .are widely distributed in Wales — throughout the north — Cader 

 Idris, 1 the Arenigs, 3 and southwards to Llandrindod-Builth 3 and 



Kg. 2. — Section across the Llanwrtyd Anticline (see map, 

 PI. 11$ p. 27). 



C I240O.D. 



Fig. 3. — Section across the Llanwrtyd Anticline (see map, 

 PI. II Sf p. 25). 



1420 O.D. 



Scales : Horizontal, 6 inches = 1 mile. Vertical, 1 inch = 440 feet. 



[The beds are numbered in accordance with the classification 



tabulated on p. 18.] 



1 A. H. Cox & A. K. Wells, ' The Ordovician Sequence in the Cader Idris 

 District (Merioneth) 'Hep. Brit. Assoc. (Manchester, 1915) p. 424. 



2 W. G. Fearnsides, ' On the Geology of Arenig Fawr & Moel Llyfnant ' 

 Q. J. G. S. toI. lxi (1903) p. 608. 



3 H. Woods, ' The Igneous Rocks of the Neighbourhood of Builth ' Ibid. 

 -vol. 1 (1894) p. 566. 



