190 H,. HICKS ON CAMBRIAN CONGLOMERATES IN 
tained in previous papers to this Society is this, that neither of these 
so-called intrusive masses could possibly be of Lower Silurian age, 
that they could not possibly have eaten into and metamorphosed the 
Cambrian and Silurian rocks in their immediate vicinity, as main- 
tained by the Surveyors, since they are truly Pre-Cambrian rocks, 
which were in their present condition before either the Silurian or 
Cambrian rocks were deposited. Where views are so diametrically 
opposed to one another as are those of the Surveyors to those 
which we have put forward, it is clear that we are bound to fur- 
nish very conclusive proofs in support of our views; and I venture 
to believe that from the evidence I have to bring before you in 
this paper, it will be allowed that the proofs are of the most con- 
clusive character, even when tried by the most rigid tests. I have 
given the rough superficial areas of these rocks, as it might be sup- 
posed from some of the remarks which have been made that, as 
geological features, their importance is scarcely deserving of con- 
sideration. ‘These, however, are but a few of similar areas which 
we claim, and when it is considered that they are now the exposed 
fragments only of part of that old Archean land which extends 
everywhere under the newer formations, and that it is in these frag- 
ments we obtain evidence of the geological structure, the physical 
history, and geographical features of that primeeval land, I believe 
the true man of science will grant that in this case the value of the 
inquiry cannot well be measured by the superficial area exposed now 
to examination. 
The visit of the (enioniete Association to Bangor in the last week 
of July offered favourable opportunities for reexamining many of 
the areas previously described, and the evidence in that neighbour- 
hood was freely exposed to the criticism of over fifty Members who 
were present. It was in the week subsequent to that visit, however, 
that, accompanied by Mr. Marr, Mr. Myers, Mr. Murray, Mr. Love, 
all Fellows of the Society, and by Mr. McPherson and Mr. Bartlett, 
and afterwards, I was able to collect the facts given in this paper, 
and I wish to express my obligations to Those, gentlemen for the 
very valuable assistance which they rendered me. 
Hitherto, though pebbles and fragments of almost every variety of 
the rocks claimed by us as of Pre-Cambrian age had been occasionally 
observed in the Cambrian Conglomerates, no actual necessity had 
arisen for making a special collection, to prove their identity with 
the rocks immediately underlying them or in their immediate neigh- 
bourhood. The importance of making such a collection, however, 
became imperative after the statements of the Director General that 
the Conglomerate in South W ales(and according to the same reasoning 
in North Wales) could not possibly contain a pebble of the character- 
istic granite (Dimetian granitoid rock), or of the quartz-felsites or 
porphyries, because, as he led us to infer, they were all newer than the 
Cambrian rocks. Moreover if we can prove conclusively that typical 
Dimetian fragments, and undoubted quartz-felsites and porphyries, 
identical with the rocks below, do occur in the Cambrian Conglome- 
rates, then, so far as North Wales is concerned, the Director General, 
