of Serpentine, Sfc. in the Apennines. 189 



sometimes taken for portions of vegetables. Now this rock 

 being considered as greywacke, by Messrs. Von Buch, 

 Brocciii, &c. consequently as a transition rock; being the 

 same as that found in the park of Doccia, two leagues from 

 Fiesole, in conformable stratification with the limestone 

 with silex, establishes, upon great presumable evidence, 

 notwithstanding the recent appearance given it by the pre- 

 sence of silex, that it belongs to the same formation as the 

 Fiesole sandstone. 



If in the mountain of Fiesole the limestone is not found 

 in place alternating with the sandstone, numerous fragments 

 of that rock are found at the foot of the mountain, indicating 

 that it is not distant. 



If we afterwards proceed to the other side of the valley 

 of Ombrone, on the hill of Seravalle, a short distance west 

 from Pistoia, a smoke-grey compact limestone is found, 

 traversed by spathose veins resembling that of Doccia, 

 Rochetta, and Pietramala; this limestone moreover contains 

 small veins of spathose iron ; it alternates with a brown 

 marly limestone, schistose, but solid, just shewing some 

 spangles of mica, in this resembling that of Rochetta, and 

 with hard micaceous calcareous sandstones, and yellowish 

 spangled clay slates, resembling those of Doccia, and only 

 differing from those of Fiesole by the small thickness of the 

 bed. 



Lower down, i. e. still more west, and towards the sea, 

 between Lucca and Massa-Rosa, above a very different 

 limestone from the preceding, and of which, for that reason, 

 I ought not to speak, beds of compact limestone are found, 

 "whitish or slightly yellowish grey, but fine grained, with a 

 scaly fracture, traversed by spathose calcareous veins, and 

 resembling, by these characters and nearly by the shade of 

 its colour, those of Rochetta, Pietramala, Seravalle, and 

 Doccia, and containing, like the last, hornstone in thin 

 seams or nodules disposed in the same line. These circum- 

 stances already make it presumable, if even they do not 

 entirely prove, that the limestone with silex is of the same 

 formation as tlic calcareous sandstones, the dull argillaceous- 



