TRANSACTIONS OF THE SECTIONS. 87 
harmony with those of Sir H. De la Beche and the Rev. David Williams, already 
spoken of, as well as that advocated by myself in an earlier paper*. It will be 
seen also that the indications of the supposed scale found by Professor Phillips were 
to the same effect. Like the Old Red Sandstone fish found in Russia by Sir R. I. 
Murchison, the Phyllolepis-scale was surrounded with marine shellst, and also by 
corals ; hence the ancient fish to which it belonged was not incapable of living in 
the sea, 
On the Gold-bearing Strata of Merionethshire. 
By T. A, Reanowm, F.GS., FSS. 
The author referred to a paper read before the Association at Manchester in 
1861, the object of which, he said, was to point out the probability of gold-seeking 
in the Dolgelley district being, at no very remote date, of commercial importance. 
He stated that, since the last Meeting, he had acquired additional facts connected 
with the subject, and his wish was to present them in support of the opinion ex- 
pressed in the paper referred to. 
The author said that he had employed an eminent analytical chemist for several 
months upon the spot, to test the accuracy of his former experiments ; and the assays 
referred to in the paper were made of 8000 grains, taken from quantities of 56 lbs., 
after the most careful sampling, instead of the customary 400 grains, 
He said that the geological features of the district were now too well Inown to 
require more than a repetition of the general statement that the rocks are of the 
Cambrian and Lower Silurian series, forming a junction in a very sinuous course, 
and frequently cut through by narrow bands of porphyritic greenstone. 
The metalliferous veins have a general bearing N.E. and 8. W., with an underlie 
to the north. 
The auriferous district under notice is comprised in the Ordnance Survey Maps, 
75, 8.E., and the upper part of 59, N.E. 
For convenience, be divides the district into the following sections ;—Cwmhei- 
sian, Maesewm, Berthwllyd, Cambrian, Clogau, and Vigra. 
The parishes included in the notice are Llanfachreth, Trawsfynydd, Llanddwye, 
Llaneltyd, and Llanaber. 
THe CwMHEISIAN SECTION. 
The Cwmheisian uchaf Mine has init more than twenty strong metalliferous lodes, 
One very remarkable junction of about fourteen lodes is 40 feet wide, and the whole 
of this mass of lode-stuff contains more or less gold. 
A large number of assays gave from 3 to 19 dwts. of gold to the ton of quartz. 
Picked specimens of galena have given as much as 16 ounces to the ton; and more 
than 170 ounces of gold were taken by Mr. Clement from about 300 tons of mine- 
ral from all parts of the mine. Mr. Arthur Dean produced 148 ounces from 1573 
tons of ore. Gold, visible in blendic quartz, has been discovered within the last 
month. 
Cwmheisian Isaf is a silver-lead mine, adjoining the last-mentioned on the south. 
The galena yields about 47 ounces of silver to the ton; and one lode in the mine 
gives, on assay, 5 to 11 dwts. of gold to the ton of mineral. 
Gwynfynydd Mine is opposite Cwmheisian Ucha, on the west bank of the river 
Mawddach. Galena from this mine, though poor in silver, has occasionally given 
as much as 8 ounces of gold to the ton. 
Hafod-y-bach Mine.—Samples of quartz, indiscriminately taken from this mine, 
gave a 3 to 5 dwts. of gold to the ton. The mineral here is probably richer 
t is. 
Tyddynglwadis Silver-Lead Mine is on the west bank of the river Mawddach, 
about eight miles from Dolgelley, in the direction of Tanybwlch. This mine is 
situate exactly at the junction of the Cambrian and Lower Silurian rocks, which is 
distinctly observable at the top of the charming waterfall, Pistil-y-Cain. 
The average quantity of silver contained in the galena is from 50 to 60 ounces to 
my * Report of the British Association, 1860, p. 100. 
ait + Siluria, 3rd edition, pp. 383 and 433. 
