232 Reports and Proceedings g 
Such a change would doubtless occur in granite and trap, if acted 
upon by carbonic-acid at temperatures below 212°; but above that 
point the very opposite would be obtained, inasmuch as silica would 
then take the place of carbonic-acid, and, consequently, if brought 
into contact with earthy or alkaline carbonates in the interior of the 
earth, would preduce silicates and expel carbonic-acid; as, indeed, 
was long ago pointed out by the author of this paper, in his work 
on voleanos, and is insisted upon by Professor Bischoff himself, in 
other parts of his volume. It seems difficult, therefore, to attach 
much importance to the cause assigned by Professor Bischoff for the 
elevation of strata; especially considering that the loss of substance 
incurred through the removal of its alkali by the agency of carbonic- 
acid, would go far towards counterbalancing any expansion due to 
the lower specific gravity of the kaolin resulting, and moreover recol- 
lecting that no theory which professes to account for the elevation 
of certain portions of the earth’s surface ought to be accepted, if it 
does not embrace likewise the corresponding phenomenon of the 
sinking or depression of others. 
In a note ON THE OCCURRENCE OF THE SAME Fossil PLANTS IN 
THE PERMIAN Rocks oF WESTMORELAND AND DuRHAM, Sir R. I. 
Murcuison stated that certain forms of fossil plants not previously 
known in the Permian Rocks of the NE. of England have been 
found by Mr. Lyall in the Marl-slate under the Magnesian Lime- 
stone of Westhoe, Durham. These, one of which is a well-known 
species (Ullmannia selaginoides), were all identical with those found 
by Professor Harkness in the plant-bearing shales of the Permian 
rocks of Westmoreland (see Journ. Geol. Soce., vol. xx. p. 154). 
Sir Roderick further remarked, that, by the occurrence of these 
plant-beds, the sandstones and conglomerates of Westmoreland have 
been shown to be the true equivalents of the calcareous Permian 
rocks in Durham. 
On THE RELATIONS OF THE SILURIAN SCHISTS WITH THE QuaRTzZOSE Rocks or SouTH 
Arrica. By R. N. Rupes, B.M. Lond. 
{pee quartzose sandstones of Table Mountain rest unconformably 
on slates and schists, and are continuous with ranges of like 
lithological character in the Eastern Province, where, however, they 
are interstratified with schists. ‘This diversity of relation had led 
former geologists to separate the clay-slate of Cape Town from the 
schists of the East and the Interior ; but the author had conjectured 
some years ago that the schists and slates throughout the Colony 
belonged to one great formation. Evidence had been brought 
forward before to show that this was probably the case ; but only 
now was it clearly established by the production of Devonian fossils 
from many localities both in the Eastern and Western divisions of 
the Colony; and a species of Anorria from Swellendam, closely re- 
sembling one from the Kowie Mouth, proved the identity of the 
schists of those two localities. A map was exhibited, which showed 
