part 1] SPILITES IN DERBYSHIEE. 25 



than the latter. The Carboniferous Lunestone was no doubt 

 a deeper-water formation than the Calciferous Sandstone; and 

 the conditions obtaining in Derbyshire, when the spihtes of that 

 area were erupted, probably more nearly approached those of 

 Cornwall at the same period than those of the Lothians. He 

 deprecated unnecessary additions to the nomenclature of rocks, and 

 thought that, if the term potash- spilites were used for the 

 Derbyshire rocks, their outstanding peculiarity would be sufficiently 

 indicated. 



With regard to the analyses, he quite agreed as to their import- 

 ance, and had every confidence in their accuracy. 



In reply to Dr. Cox, he agreed that, although no active folding 

 or faulting took place when the Derbyshire rocks were erupted, 

 there was clearly a state of slow and prolonged subsidence, although 

 not to the same extent as in Cornwall, and this might have been 

 a factor in the evolution of the rocks. 



