202 Votices of the Geology and Monerulogy of Sicily. 
Pelorus. This granite is very compact; its feldspar is most 
abundant, and often porphyritic in rhomboids. It is abun- 
dant in large blocks, at the base of the mountain, particu- 
larly in the valleys and water courses. 
@neiss covers the granite on the sides of the chain. At 
often contains nodules of earthy iron ore. Mica slate is 
found at the base and sides of the chain, and forms secon- 
dary ridges extending far towards the centre of the island. 
Feldspar often constitutes large veins in the granite, and 
forms entire blocks in the debris of the mountains. There 
is a coarse grained granite, easily disintegrating, which Prof. 
F. calls secondary granite. It is probably the coarse, friable 
granite, so common in veins in gneiss and mica slate. 
There is a band of Transition Rocks running along the 
whole W. front of the mountains of Pelorus, and extending 
from Capo Grosso on the N. nearly to the centre of the 
island. They consist of Petrosilex, schistose and compact ; 
Argulite, (Ardesia) in inclined strata, forming low moun- 
tains, alternating with hills of chalk and shell limestone; it 
is the matrix of nearly all the metallic ores of the island; 
Pietra Cornea, schistose and compact; including trap or 
greenstone; Porphyries of many varieties, with a base of 
petrosilex or feldspar; serpentine and steatite in scattered 
masses at the base of Pelorus; and various aggregated 
_ rocks. ‘The nomenclature of the author is here rather an- 
tiquated: we would venture to class the rocks here enu- 
merated under the heads of argillite, wacke, greenstone, 
gray-wacke, &c. Perhaps the limestone alternating with 
the argillite may be similar to the shell limestone with in- 
clined strata, in a similar relation to the argillite in Dutch- 
ess, N. Y. 
The limestone of Sicily i iS arranged under the following 
divisions: 1. Primitive in the veins of gneiss and mica slate, 
not abundant, too scanty and friable to be wrought for mar- 
ble; dolomite is not uncommon: Transition, (Calcaria an- 
tico) fine grained, compact, grey, often foliated; found in 
the Nebrodes, and in the mountains around Palermo, &c. 
generally very fine grained, and hard as flint; forms excellent 
lime ; sometimes contains anomias, medusas, &c.; sometimes 
destitute of organic remains; generally occupying the base 
of the mountains, and covered by a coarser shell limestone : 
Compact, fine grained, often with a confused crystallization, 
abounds in petrifactions, sometimes contains impressions pf 
