42 Reports and Proceedings. 
Journal. Mr. Churchill suggests that the formation of Dolomite 
may be going on in coral reefs at the present day ; for the speci- 
mens of cor al rock brought home by Dana from the raised island of 
Matea, or Aurora, were found to contain in one case 5 5 per cent., and 
in another as much as 88 per cent., of carbonate of magnesia. 
And if we suppose the Dolomite mountains of Carinthia to have 
been formed on a gradually subsiding basis, they may have grown up 
like the low islands of the Pacific, till the sea attained the “depth of 
a thousand fathoms, preserving their original contour from first to 
last, the groups of “corals, like a forest of tree-trunks without tops, 
rising upwards together, and becoming partially solid by lateral 
er owth, or by filling up with sediment. 
We have no fossil coral-reef in England wherewith to compare the 
Dolomite Mountains. Our Magnesian. limestone affords only Bryozoa, 
for it has not been suspected that the remarkably concentric and 
radiated concretions are metamorphused corals. In our Silurian 
coral-reef of the Wenlock Edge and Dudley there may be masses of 
branching coral a yard across, and convex Stromatopore (which are 
not corals) of nearly equal size. But the coral-beds are separated 
by clay partings, and never attain a great thickness. The Devon- 
shire marbles have much the appearance of coral-reefs, so far as 
respects the scattering of small masses over a region of argillaceous 
schists. In the Carboniferous Limestone layer above layer of branch- 
ing corals may be seen in the lofty cliffs of Cheddar and the weather- 
beaten shores of Lough Erne. There the corals are slightly silicified, 
and stand out in relief, while the mass of the rock is composed of 
sediment with Foraminiferal and Encrinital débris. The Coral-rag 
forms a reef in some parts of Wiltshire, but it is rarely seen in sec- 
tion ; the corals are usually obtained as stones from the ploughed fields. 
The conversion of a limestone coral-reef into Dolomite becomes 
comparatively easy of belief, since Mr. Sorby has shown that coral 
(like nacre) has the constitution of aragonite, a much less stable 
compound than calcareous spar. 
Pearly shells are never preserved in calcareous rocks, unless in a 
metamorphic condition. And the corals of the Oolite formation are 
usually silicified, like those of Tisbury in Wiltshire and Nattheim in 
Germany, or replaced by structureless calcite full of sparry cavities. 
Tt is now also well-known that the masses of annulated chalcedony, 
called ‘ Beekite,’ found in the neighbourhood of Torquay, are Devo- 
nian corals more or less completely replaced by silica, for they are 
sometimes hollow, and in other instances containa nucleus of fossil coral. 
REPORTS AND PROCEHD_ DINGS. 
SEUSS 
THE GEOLOGICAL SOCIETY OF LONDON. 
ct following communications were read, May 25, 1864 :— 
‘On the Geolog gy of part of the North-western Himalayas.’ 
By Captain Godwin- Aiea, With Notes on the Fossils; by Messrs. 
T. Davidson, R. Etheridge, and S. P. Woodward. 
