134 DE. G. L. ELLES OX THE EALA COUXTEX : [vol. Ixxviii, 



states that the limestone is ashy in j^laees. and also non-calcareous 

 occasionally, ' when it is not to be differentiated from the sand- 

 stones/ He does not, however, consider that the Bala Limestone 

 is distinct from the Ehiwlas, being unappreciative of the value of 

 the pahi?ontological evidence. 



He records the existence and nature of the Hirnant Limestone 

 at the head of the Hirnant Valley, and notes the position of beds 

 of the same age at other localities. 



His remarks on the structure of the counti-y are highly sug- 

 gestive : he notes the existence of the anticlinal line separating 

 the synclinal lines of Bryn Pig and Creigiau Bychain,^ notes the 

 broken nature of the ash outcrops, and calls attention to the 

 parallelism of certain lines of faulting. He also suggests that the 

 lake lies in a trough open to the south, of which the apex lies 

 north of INIoel Emoel at Pen y Bwlch-gwyn. He estimates the 

 thickness of the beds between the ash and the limestone as i-anging 

 fi-om 1200 to 1100 feet. 



In his admirable paper ' On the L'pper Part of the Cambrian & 

 Base of the Silm-ian in Xorth Wales,' Thomas Euddy^ de- 

 scribes definite lines of section, and makes the earliest attempt at 

 a palteontological classification of the beds, the fossils from each 

 horizon being sedulously recorded and the actual succession seen 

 at certain localities carefully described. The nature of the Hii-nant 

 Beds, apart from the limestone, is noted, and attention is drawn to 

 the chano^e in chamcter which ther undersro when ti'aced alonsf 

 their strike as ako their relation to the overlying Tarannon Beds. 



Baddy was an indefatigable collector, although his collections 

 were not always made from beds in situ, and his fossil lists have 

 been of the greatest service to me, especially the summary given in 

 his ' List of Caradoc or Bala Fossils found in the Xeighbourhood 

 of Bala, Corwen. & Grlyn Ceiriog.' '^ 



Buddy's sections are generally easy to follow, with the exception 

 of that across Gelli Grin, where the faulting of the beds appears 

 to have escaped his notice, and therefore two ash-beds are noted 

 instead of one. He accepts the official view as to the identity of 

 the Bala and Bhiwlas Limestones, but considers the Hii^nant Beds 

 to be of Llandovery age. 



Sir Andrew Eam.say^ was the first to mention the continuity 

 of the Dee-Yallev and Bala-Lake fault, statins: that it has an 

 invariable downthi'ow to the north-west, so that part of the strata 

 south and east of the lake are repeated by it and reappear on the 

 west and north. 



He estimates the maximum amount of throw as 12,000 feet ; 



^ The spelling of trie place-names adopted in this paper is that used in the 

 6 -inch Ordnance StiTTey maps. 



^ Q. J. G. S. vol. XXXV (1879) p. 200. 



3 Proc. Chester See. Xat. Hist. no. 3 (1885) p. 113. 



^ Q. J. G. S. vol. ix (1853) p. 161. 



