101 MINERALOGICAL DESCRIPTION 



In many parts of the rock I have found concretions, in which 

 there are no bones of any kind ; and on the elevated parts of 

 the mountain, where the flopes are rapid, I have found a breccia, 

 (if 1 may fo call it), entirely confiftnig of fnail-fhells, combined 

 in a mafs of opaque ftaladlltical fpar of a yellowifli brown co- 

 lour. The various progreflive augmentations of this matter 

 were to be traced in various fhades of the fame colour, which, 

 like the zones of the antique alabafter, curve round, and fol- 

 low the form of the fhell. The purer matter of this fpar has 

 penetrated the ihells, and in their interior hollows has formed a 

 lining of fmall cryftals, generally colourlefs and perfe(flly tranf- 

 parent. 



I HAVE beftowed more time in endeavouring to defcribe the 

 compofition, and the real fituation, of this concretion of bones, 

 than the fubje<5l, in the eftimation of many, will feem to de- 

 ferve, and indeed more than it deferves in my own opinion ; but 

 where an erroneous opinion has obtained a footing, in confe- 

 quence of inaccurate obfervations and partial defcription, it is 

 the duty of every new obferver to endeavour to corre(5l it. 



X. 



