226 LOM'EE PALAEOZOIC OF LLAXGOLLEX DISTEICT. [vol. Ixxviii, 



regard to the Bala Series, lie welcomed the introduction of a group 

 of beds into the gap caused in the Ceiriog vallev by the Dolhir 

 Fault, which Mr. Lake and himself had only partly succeeded in 

 filling. He lastly suggested the importance of recognizing phases, 

 in such movements as the Caledonian, and remarked that the 

 evidence that had been given hardly sufficed to prove absolutely 

 the ' Devonian ' as^e of the earlier foldino- and faultinsr. and did not 

 seem to take into consideration the possibility that important 

 movements may have taken place in late Silurian or early Car- 

 boniferous times. 



Dr. AYiLLS, in replying, expressed his gratitude for the kind way 

 in which the Fellows present had received the paper — gratitude in 

 which he knew Mr. Smith would join. Many j)oints had been 

 raised in the discussion, and he could only attempt to answer 

 some of them. Miss EUes's determination of the graptolites from 

 the Blaen-y-Cwm Beds — which were very distorted — suggested a 

 zone even lower than that of ^l.€urogra])iii8 linearis. She was, 

 he believed, re-examining them in the light of better-preserved 

 material from a similar stratigraphical horizon in the Southern 

 Berwyns — material Avliich appeared to indicate the Swedish zone 

 of Diplogrctjjtus pristis. The Authors thought that in the 

 western part of the Xorthern Berwyn outcrop, the sequence from 

 Caradocian to Ashgillian was probably complete ; but there was 

 not enough palseontological evidence to prove this conclusively. 



The terra ' nodal anticline ' ref eiTcd to the supposed function of 

 the anticlinal cores of Ordovician, as hard knots relative to the 

 less-resistant Silurian strata ; the term ' anticlinal buttress ' had 

 been suggested for the projection of the Berwyn Anticline, which 

 was necessitated b}" the sharp difference in strike in the Central- 

 Wales Syncline and in the Llangollen Synclinorium, and by the 

 pitch of the latter. 



The Authors had traced the Corwen Grit from Corwen to Grlyn- 

 Ceiriog, and found that near Grlyn the massive uncleaved Conveii 

 Grrit overlies part of the Grlyn Grit ; but they regarded it as a 

 lithological variation of the upper part of the Glyn Grit of Glyn- 

 Cemos:. 



