Ixxvi PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
island of paleeozoic rocks of the date to which allusion has been pre- 
viously made, on the shores of which conglomerates and other rocks 
of the old red sandstone were accumulated. These again were covered 
up by the beds of the great carboniferous limestone, one of the most 
marked accumulations of the British series, especially for the evidence 
it affords of general similar conditions having existed over a large area 
at the same period, the modifications of these conditions beimg very 
gradual, though at the same time very marked, in different parts of 
that area. 
It is probable that, like the Mendip Hills at a subsequent geologi- 
cal period, this island-land became covered up, as it was depressed 
beneath the sea, by the accumulations of the old red sandstone and 
the carboniferous limestone ;—these accumulations again to be in a 
great measure removed. by those extensive denudations which we have 
abundant evidence to show took place over this region. 
Reposing on the part of the series in which the igneous rocks occur, 
and beneath a thick accumulation, chiefly arenaceous, the beds of 
limestone are found in which the fossils noticed by Prof. E. Forbes 
were discovered. Many of the fossils from the Chair of Kildare had 
previously been obtained by members of the Geological Society of Ire- 
land, and are to be found im the collections of Mr. Griffith, where 
they have been described by Mr. M‘Coy. Availing himself of all 
the sources of information presented, Prof. E. Forbes, taking zoolo- 
gical evidence for his guide, considers that these limestones of the 
Chair of Kildare are not only referable to the Lower Silurian series, 
but members of the lowest part of it, and equivalent to the Bala 
limestones and their associated beds in North Wales. A comparison 
of the fossils from the Chair of Kildare with those obtained from the 
limestone of Courtown, county Wexford, leads Prof. E. Forbes to re- 
gard it as highly probable that the limestones are equivalents, and 
that both are representatives in Ireland of the Bala limestones, a point 
of much importance as regards the accumulations during the same 
time in the British area. : 
GEOLOGICAL SOCIETIES OF CoRNWALL, MANCHESTER, AND THE 
West RipinG oF YORKSHIRE. 
Societies formed for the purpose of advancing our science are not 
confined even in this country to London and Dublin. For thirty- 
four years the Royat GroLocicaL Society or CORNWALL, in- 
stituted for ‘‘the discovery of facts to enrich science and the appli- 
cation of science to improve art,” has endeavoured to promote the 
knowledge of Geology in the great mining districts of Cornwall. To 
induce agents and others connected with mimes to join the Society in 
its pursuits, practical miners have been admitted during the past 
year to nearly all the privileges of the other members, at one-fourth 
of the annual contribution of the latter. The seventh volume of the 
Transactions of this Society is now in progress, and among the papers 
made public through these Transactions, many are well known to us 
as possessing great value, and as having aided the progress of Geology 
