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‘ 
Prof. Hughes—Lower Cambrian, Bethesda, N. Wales. 9 
subjected. The announcement that Mr. Robert Lloyd had discovered 
fossils in the uppermost slate beds of the Penrhyn Quarries was 
therefore received with great interest, which was increased when it 
was found that some of these were in a sufficiently perfect state for 
determination, and that they were referred by Dr. Woodward' to 
a new species of a well-known Lower Cambrian genus of Trilobite. 
I have since found fragments of another smaller species in the 
same beds not far below the Bronllwyd grit. 
The zeal of Mr. Robert Lloyd, to whom I am indebted for much 
valuable information, especially with reference to the subdivisions 
and measurements of the Penrhyn Slates, has recently been rewarded 
by the discovery of traces of fossils in the part of the quarry known 
as Sebastopol, some 1200 feet lower in the quarry than the 
Conocoryphe. viola zone. 
Unfortunately these specimens also are too obscure for determina- 
tion. ‘They appear to be the casts of the carapace of a Trilobite filled 
with radiating mineral matter, and are of somewhat the same size 
and outline as those of Conocoryphe viola. 
I have thought it might be of interest to offer a few notes on the 
rocks seen in a traverse from a point a little west of Bethesda across 
the Penrhyn Quarries over Moel Perfedd to Cwmbual on the south, 
with a view to fixing the position of the only fossil zones yet known 
in that area, and pointing out the localities where it seems most 
probable that fossils may yet be found. The accompanying diagram 
section will facilitate reference :— 
MOEL PERFEDD CARNEDD 
2 Y FILIAST BRONLLWYD 
eo PENRHYN 
cwM aw i . 
ri CEUNANT POSSE QUARRIES ST. ANN’s 
GHAPEL 
| Hi h | 
ji li! h © 
DOLOWEN 
TAINEWYDDION 
Fic. I.—Diagram Section N.N.W. and §.S.E. from St. Ann’s Chapel to Moel 
Perfedd. Length of Section 2} miles. The cleavage is nearly vertical N.N.E. 
and 8.8. W. 
* Indicates horizons at which fossils have been found. 
A. The slates south of Moel Perfedd are dark grey irregularly 
cleaved lumpy sandy beds which at one place dip at an angle of 
about 40° to the north, that is, towards the felspathic rock. 
B. This felspathic rock behaves as an intrusive mass. It is not 
seen down the hill side to the bottom of the valley. é 
C. Black and grey slaty rock fills up the interval between Moel 
Perfedd and Carnedd Filiast. In this Cwm Graianog has its origin. 
D. The grit of Carnedd Filiast is inclined at a high angle and 
runs down the north side of Cwm Graianog protruding in rough 
bosses near Tainewyddion. Here it is split up by finer beds upon 
the face of which Cruziana semiplicata is abundant. 
1 Quart. Journ. Geol. Soc. vol. xliv. pp. 74-78, pl. iv. 1888. 
