260 Dr Daubeny 071 the Geology of Sicily. 
The description given by Brocchi, of the calcareo-arenaceous 
breccia, which accompanies the marl of Italy, corresponds 'equal- 
ly with what I have observed, respecting that of Sicily, and 
strengthens the probability that the two formations are iden- 
tical. 
I have now to describe a series of rocks, which occupy the 
southern portion of the island, extending from Cape Passero 
(formerly Cape Pachynus) to the Lake Lentini, where they are 
interrupted by a diluvial tract, termed the Piano di Catania, 
but are seen again northward of that district, near Catania, and 
in a few other places, where the rock has escaped being covered 
by the lavas of Mount Etna. 
I traced these beds uninterruptedly, from Terranuova to 
Cape Passero, and found them to consist either of a soft earthy 
looking limestone, generally of a straw colour, which, in some 
of its varieties, resembled the beds occurring in the oolite of this 
country, or of a breccia, in which nodules of a more compact 
limestone were imbedded in the earthy looking basis, before de- 
scribed. 
In the south of the island, near the town of Ragusa, this for- 
mation contains beds of limestone of a black colour, owing to 
the presence of bituminous matter with which it is so strong- 
ly impregnated, that thin pieces of it will bum in a candle, leav- 
ing an earthy residuum ; and it is even said, that the inhabitants 
use it as fuel. Near Palagenia, west of Lentini, is a lake called 
Lago Naftia,, which is constantly giving out petroleum ; it is si- 
tuated in the same formation *|\ In many places natural ca- 
verns are found, in which a large quantity of nitre is collected, 
the constituents being probablyfurnished, in a great measure, by 
the dung of the bats, which resort there, in vast numbers. 
It is curious to observe, that the natural caverns are frequent- 
ly incrusted with stalactite, though the artificial excavations, 
found in great numbers on the same spot, the antiquity of which 
cannot be questioned* seem altogether free from them J. 
* I find that the Ragusa limestone contains near 14 per cent, of bituminous 
matter. 
-J* See Ferrara’s Pamphlet on the Lago Naftia. 
£ These artificial excavations are extremely curious, in an antiquarian point of 
view, and do not seem to have been sufficiently noticed. In some places, as at 
