- wit 
wn ee 
‘Rotten-Stone. 317 
intermediate between Rotten-stone and per- 
fect limestone; Rotten-sione mith nuclei of 
solid black limestone; Ke. &c. 
8. The calcareous stone, which forms, in 
these instances, the central parts of the nodu- 
lar lumps of Rotten-stone, has the eziernal 
characters of the black limestone or marble, 
found at Ashford-in-the-waters, &c. but dif- 
fers, somewhat, in its internal properties,’ 
from any stratum of limestone yet discovered 
in Derbyshire. 
9. Marine reliquia are sometimes found in 
the hard Rotten-stone ; and these are gene- 
rally such as have been observed to be most 
frequent in the black marble ; viz. Entomoli- 
thus Derbiensis, Conchyliolithus Breynii, &e. 
(v. Pet. Derb. T. 45, 39, &c.) 
Such are the principal phenomena, which 
were noted during my examination of the 
depot of Rotten-stone near Bakewell.—The 
conclusions, to which this examination led, have 
been already alluded to; namely, that Rotten- 
stone is produced by the disintegration of a 
particular variety of limestone, probably a 
black marble ; and that, consequently, authors 
are incorrect in considering the original sub- 
stance of this fossil to have been an argillace- 
ous stone. 
It will here, however, be asked—how is 
