412 EXCURSIONS. 
After a walk of about \h miles along the railway Hendre 
Quarry at Pen-y-Bont was reached. 
Near their line of junction with the Igneous rock, whicli is 
much more basic than that at Cae Deicws, the slates of the Bala 
Series are considerably altered, as is shown by the occurrence 
of Spotted-slate and (.-hiastolite-slate, both of which are pi'o- 
duced as the result of the action of heat upon ordinary Clay- 
slate. The Igneous rock, which is basic and holocrystalline, is 
probably a Keratophyre, containing much augite and an acid 
felspar, and is used for setts and road metal. 
From Hendre Bridge the party returned to Glyn Ceiriog 
and drove thence by Castle Mill, where several exposures in the 
Carboniferous Limestone were examined, to the large quarry at 
Bron-y-Garth on the right bank of the river. 
The sections at Castle Mill were found to be in the same 
beds (D2) as those examined earlier in the day, and the same 
was the case at Bron-y-Garth, where 100 feet of strata were 
exposed, consisting for the most part of limestone, but with a bed 
of shale some 20 feet in thickness near the top. 
The following fossils were obtained : — 
Lonsdalia duplicata. 
Lithostrotion jiinceum. 
L. irregular e. 
L. McCoyanum. 
THfhyphyllum. 
Cyathophyllu7n regium. 
Cydophyllurn pachyzndothecum. 
Producius latissima. 
Phillips ia sp. 
These rocks were stated to rest directly upon Bala Beds, 
which would place the local base of the Carboniferous exception- 
ally high in the series. No section showing the actual base of 
the series could, however, be found. 
A General Meeting of the Society was held in the evening 
at the Wynnstay Hotel, under the presidency of Dr. Dwerry- 
house, a number of members of the Liverpool Geological Society 
being present. 
