420 Notices and Extracts from the Minutes of the Geological Society. 



and at {a), from the same cause^ the inferior rock is alone visible ; but at (c) 

 the rocks again appear in the same relative situation as at {f), and afford 

 every facility for examination. 



The upper stratum is a dark coloured rock, apparently fused ; and vs^hich 

 mig-ht be called, from its external appearances, a compact lava. Abundant 

 veins of arragonite intersect it and coat the surface of its cavities, and even 

 cause it in some places to assume the appearance of a breccia. This breccia, 

 which crowns the cliff, is of considerable depth, perhaps from 8 to 12 feet ; 

 its structure is tabular, and it separates into horizontal plates, some a foot in 

 thickness. At the point of junction it is found of a red colour and decom- 

 posed, and the stratum below is also tinged for some short space with red. 

 This lower stratum appears to be a tertiary limestone, containing the exuviae 

 of a large species of ostrea, and rolled pebbles of a rock similar to that by 

 which it is surmounted. It hes in layers a foot or two in thickness, at (c) a 

 little depressed to the south-east. Its substance is a greenish sand filled in 

 parts with yellow pisolitic concretions, of which it is composed. 



Inland appears a succession of tabular ridges with steep declivities. That 

 on which the town is built, is about 500 or 600 yards broad. The hills are 

 bare of vegetation, though perhaps covered with a scanty herbage in the 

 rainy season. Cotton and coffee are grown : the soil is unpropitious for trees, 

 and the palmyra, used in basket-making, is alone planted. 



Inland, about 3 miles, is an outlying conical hill (g-), rounded at the top, 

 higher than the surrounding country, of a deep red colour, from which the 

 material of a pottery, more compact than the English, is extracted ; and some 

 sparkling substance, probably pyrites, which it contains, the ignorant inhabit- 

 ants imagine to be gold. Ranges of hills still higher, and of irregular out- 

 line, terminate the back ground, centring in a nearly perpendicular peak. 

 There is no account of any modern volcano in the island. 



