so Dr. KiDD on the Mineralogy of St, David's. 



and th-e general character of them is crystaUine : but the felspar 

 rarely if ever occurs in distinct crystals ; and e\'en the hornblende, 

 though usually the most accurately defined of the two, is sometimes 

 not discernible from the felspar. Again, though the mass often 

 appears upon the whole to have been of chemical origin, yet at the 

 same time it is, partially, of a structure to the eye decidedly mechani- 

 cal ; and in some instances the character is so extremely equivocal as 

 to leave the judgment in a very difficult state of suspense. The 

 predominating colour of these crystalline rocks is a brownish green. 



The two highest of these hills, called Carnllidy and Penben-y, are 

 situated to the north of St. David's : they rise less abruptly from 

 the plain than the similar hills of the neighbourhood ; and are in a 

 manner connected with each other, and with a third summit not far 

 distant from the last mentioned, by a slightly elevated ridge whicli 

 passes in a south-westerly direction from one hill to the other ; 

 Penberry being at its north-eastern extremity. From the summit 

 of Carnllidy the ground gradually slopes towards the west for a few 

 hundred yards, and then, again rising, forms the promontory called 

 St. David's Head. 



The ascent to the two hills above mentioned, both on the north 

 and on the south side, is formed by highly inclined strata of a slaty 

 rock which would be commonly called grau-wacke, a term in the 

 present instance used only for the purpose of general description ; 

 and the nearly precipitous cliffs, by which the greater part of the 

 adjoining coast is bounded for some miles, appear to consist 

 principally of the same kind of rock. The massive tabular laminae 

 of this schist rise abruptly from the sea, with a highly elevated 

 degree of inclination towards the land, over the edge of which they 

 are sometimes folded in the form of a broad mantle, or are occasion- 

 ally broken into natural arches and caverns j giving to the outline 



