TRAVELS IN BRAZIL. 



59 



calcareous spar of a greyish white or yellowish 

 brown colour. In single drused cavities, the spar 

 is remarkably foliated, and sometimes crystallised 

 in pretty large tables. This limestone rock is, es- 

 pecially towards the N. W. side, more stratified 

 on the surface than deeper down, and contains 

 several smaller and larger caves, so that there can 

 be no doubt that the prevailing formation belongs 

 to that of the Jura, or cavern limestone. In the 

 mass of the limestone itself we discovered no shells, 

 except a single species of sea-snail resembling the 

 Buccinum undatum. The largest of the caves, 

 Gruta de S, Miguel of the Spaniards, or Saint 

 George's cavern of the English, situated almost in 

 the middle of the rock, and 1100 feet above the 

 level of the sea, contains a beautiful grotto, sixty 

 feet high, and two hundred deep, adorned with 

 various sparry petrifications, and supported by co- 

 lossal stalactical pillars. The limestone in this 

 cavern is traversed by vast fragments of a very 

 fine brown stalactite, of which there are large 

 mantlepieces in the house of the governor. The 

 Pocoroca is a similar cavern, but not so deep. 

 The tendency to the stalactic formation appears, 

 however, not only in the vast pillars of the caverns, 

 but also in the outside covering of many pieces 

 of rock exposed to the air, which have a coat 

 of yellow striped stalactite. On the south side 

 of the town we observed, in the red clay of a 

 ditch, several considerable pieces of a smoky grey 



