688 PROF. T. M‘KENNY HUGHES ON THE PRE-CAMBRIAN 
We must therefore consider the lowest of the Bangor beds visible 
in that area to be the coarse brecciated conglomerate seen near 
Careg Hwfa, immediately S.E. of the purple grits. This con- 
glomerate is very conspicuous with its large pebbles of green 
felspathic rock weathering milk-white. The dip of the volcanic 
beds is very clear, averaging about 55° S.E.; and as we follow them 
along their strike to the N.E. we find them disappearing under the 
Cambrian conglomerates and grits, which can be traced lapping 
round the end of the hill from near Minfford to below the Mount. 
So it will be seen, first, that all the older groups run parallel to 
one another between Caernarvon and Bangor, the strike nearly 
coinciding with the trend of the hills, with a little more north in it, 
and dragged down towards the great faults here and there. 
Secondly, that a connected though variable series, consisting 
of grits and conglomerates, flanks them on the 8.E., and folds round 
the north-eastern end of the several masses into which the range 
is cut up by valleys, overlapping in turn each of the four groups 
into which the older rocks have been divided, and changing their 
character somewhat according to the rocks on which they rest and 
from which they were principally derived. These grits and con- 
glomerates I refer to the base of the Cambrian, and I now propose 
to trace them more in detail. 
Cambrian. 
We find them well developed on the shore S.W. of Garth Point, 
where there is the following section :— 
Fig. 8.—Section seen along Shore of Menai Straits between Garth 
Point and Gored Gith, Bangor. 
N.E. 8.E. 
Garth 
Ferry. Slate Depot. Gored Gith- 
x. Carboniferous. 
a’, Even-bedded mudstones and finer sandstones. 
a’, Coarse grit, with lines and beds of quartz and jasper pebbles. 
a, Pale mudstone, with subordinate purple beds, especially in lower part. 
a, Coarse conglomerate. * Broken faulted ground. 
Sandy mudstones with subordinate purple beds are seen here and 
there in road-cuttings and elsewhere on the hill above, and the con- 
glomerate can be traced obliquely up the hill-side. It crops out 
below Menai View, runs across from that to near Friddodd, and 
is exposed in a large quarry near Plas Lodwig. It is seen, well 
scored by glacial strie, in the road that leads from Friddodd 
towards Belmont. Probably one of the faults seen on the shore 
near Gored Gith cuts it off on the S.W., and it is thrown forward by 
