THE VALE OF CLWYD. 27 
Syenite, and many other rocks igneous and metamorphic, which 
are more likely to have come from the Lake District and Scotland 
than from their Welsh geological equivalents. 
Then as to the paleontology of the beds—looking at 
Mr. SuHone’s list of shells from the marine drifts of Cheshire 
(see Quart. Journ. Geol. Soc., Vol. xxxiv., p. 383,) and at 
Mr. Gwyn JEFFREYS’ list of the shells of Moel Tryfaen (see 
Quart. Journ. Geol. Soc., Vol. xxxvi., p. 351,) the shells I have 
as yet found in the Clwydian drift (see p. 29,) even allowing 
for the difference in the number of species obtained, would 
seem not to indicate quite so cold a climate. Perhaps the area 
examined by Mr. SHONE was submerged more early than the 
Vale of Clwyd, and before the ice had receded so far, and was 
more chilled by floating ice from the North—while the Moel 
Tryfaen shore, from proximity to the great mountains, would 
also in all probability be longer affected by the chilling glaciers. 
The valley of the Chwiler, or Wheeler, inosculates with that 
of the Alyn, which flows into the Cheshire plains. On the 
flanks of the hills there is a stiff boulder-clay probably of early 
glacial age; but all along the valley, in great mounds and ridges, 
there is a red sandy deposit which it seems pretty clear belongs 
to the marine Clwydian drift, when the sea had taken the place 
of the glacier ice and was swilling up and down through the 
strait. On the other side of the Vale the same kind of sand 
and clay is seen in the river cliff below the road from Pont- 
yralltgoch to Wigfair, and fragments of shell, chiefly Ze/dina 
balthica, are not uncommon. The principal section, however, 
is in the river cliff near Brynelwy, where there is a mass of 
gravel, sand and boulder-clay now somewhat confused by 
landslips, but still furnishing evidence of the occurrence of a 
reddish boulder-clay above, sand and gravel in the middle, and 
grey or blue boulder-clay below less clearly seen. Shells and 
flint occur all through the two upper divisions. In the gravel 
and sand I found balls of reddish clay with Silurian fragments 
only included in it, but with the outside stuck all over with 
sand and gravel similar to that in which it was imbedded. This 
was evidently a fragment of an older boulder-clay formed not 
far off. It had the purple stain of the New Red, and had been 
rolled along the shingly shore in the sea in which the Clwydian 
Drift was deposited, just as I have seen the sea rolling balls of 
boulder-clay along the shore at Colwyn, and near Penrhos in 
Anglesea, or balls of London clay in the Isle of Sheppey. 
Those all had fragments of stone and shells stuck over the 
outside till they looked like pebbles of conglomerate. 
In the reddish boulder-clay well scratched stones occur, but 
one fragment I found which showed that the stone had been 
broken up after it had been glaciated. Probably it had been 
exposed in a cliff of ancient boulder-clay which was being 
denuded, and the stones in it were shivered by the frost or sun. 
