274 PEBBLES FROM THE LOWER CARBONIFEROUS OF NORTH WALES. 
it, while they invariably show the most complete unconformity with 
the Silurian beds below. 
Discussion. 
Mr. Dre Rawncz expressed his agreement with the paper after 
having walked over the ground. He also thought that the source 
of the pebbles had probably been the Lake-district or old destroyed 
lands under the Irish Sea. He had been informed ‘by Mr. Morton 
that, in examining the caves in the Carboniferous Limestone near 
Abergele, east of the direction of the author’s section, a number of 
these fragments had been found, showing underground drainage 
from the outcrop of the basement beds to the sea. 
Prof. Hueues bore testimony to the accuracy of the observations 
of the authors, but thought caution was needed in accepting some 
oi their conclusions. A bed might be stained in a conglomerate of a 
colour which it never bore in situ. Pebbles from grey rocks in the 
red basement conglomerates of the Carboniferous rocks in the Eden 
valley were stained red. He also thought that the general character 
of the pebbles did not agree with the Ludlow of the Lake-district. 
All the fossils were Ludlow, but also occurred low down in the 
Denbigh Flags. 
Mr. A. O. Watxer said that the conglomerates above these beds 
were of greenish or whitish pebbles, and so not in the least stained 
themselves. He thought that the pebbles in the caves mentioned 
by Mr. De Rance occurred in the drift. 
Mr. Rurtey said that an exposure of Upper Ludlow rock in the 
Long Sleddale valley of the Lake-district had a lithological character 
identical with that of the specimens brought by the authors. 
The Preswpent asked if there was any physical evidence as to the 
direction whence the pebbles had drifted. 
Mr. Srrawayn said that probably the hardest portions of the rock 
survived in the existing pebbles, which, however, were softer than 
the Wenlock shale. There was no other rock of similar character 
in the district. He also thought the general position of the beds 
favoured the idea of denudation they had suggested ; but there was 
no certain physical evidence as to the direction whence the fragments 
had proceeded. 
