DR. HICKS IN ANGLESEY AND N.W. CAERNARVONSHIRE. 207 
Discussion. 
Mr. Lyprxxer remarked on the similarity of these rocks to those 
in the Himalayas. But in that district it was certain that a Pre- 
Cambrian rock, which supplied pebbles to the Paleozoic schists, 
could not in many cases be distinguished from granitic intrusive 
rocks of post-Silurian age. 
Mr. Torrey said that the Director-General of the Geological 
Survey had dealt in his paper with the St. David’s area, and was 
not bound to follow Dr. Hicks into the collateral issues he had 
raised. He said that Sir A. Ramsay had fully described these beds 
of conglomerate, and had stated that the metamorphic and granitic 
pebbles, though apparently derived from the rocks of the district, 
were not of local origin, as he considered there was evidence to 
prove the later metamorphism and intrusion of the rocks. The 
speaker stated that the Cambrian quartzose conglomerate of St. 
David’s was very different in character from that now described, 
and he invited Dr. Hicks to produce pebbles of the St. David’s 
Dimetian from that conglomerate. i 
Prof. Spniey said that Sir Andrew Ramsay had recognized the 
presence of pebbles in the Cambrian conglomerates as proof cf the 
existence of rocks older than the Cambrian; and he had also de- 
scribed an actual passage in Anglesey by metamorphism through 
schists into true granitic rocks. In these North-Welsh areas the 
succession of a central mass of granite surrounded by felsite, with 
ashes further away, was so like the condition described by Professor 
Judd in the central masses of the Grampians, that he asked whether 
Prof. Judd’s interpretation of the Scotch areas might not apply in 
Wales. And when there were no ashes, he thought the granitic 
and felsitic rocks were situated in these Pre-Cambrian masses as 
they would be if due to metamorphism. The denudation of such 
rocks might have furnished the pebbles described. 
Mr. Marr said that Prof. Sedgwick had recognized the fact that 
his Cambrian strata were underlain by older deposits. He denied 
the existence of metamorphism in the conglomerates—such meta- 
morphism, ¢. g., as that described by Reusch in the conglomerate of 
Norway. He insisted on the exact similarity between the pebbles 
of the conglomerates and the different varieties of Pre-Cambrian 
rocks in the immediate neighbourhood. 
Dr. Hicks agreed with Mr. Marr that the existence of Pre-Cam- 
brian rocks had been recognized by Prof. Sedgwick. He admitted 
the great value and importance of Sir A. Ramsay’s work in North 
Wales. He had not evaded the question as applying to the St, 
David’s area, but would very shortly deal with it, and bring forward 
also from that area evidence as conclusive as that which he now 
placed before the Society from North Wales. The Director-General 
and his assistants were entirely wrong in their conclusions about 
the St. David’s conglomerates. 
Prof. Bonney said he thought that it was not so difficult as Mr. 
