192 
from them. The marble does not always display the forms of these 
remains with equal fineness and perfection : Rickledale, Monyash, 
and Breks, he mentions as affording the most beautiful.* At present, 
none, perhaps, exceeds that which is obtained in the neighbourhood 
of Ashford in the Waters. Da Costa remarked, fifty years since, of 
the Derbyshire marble, that it is degraded by the common name of 
limestone ; and the country people, ignorant of its value, only burn it 
for lime, although for hardness, beauty, and susceptibility of polish, 
it may vie with the most esteemed foreign marbles. 
Mr. Mawes, in his Instructive Mineralogy of Derbyshire, observes 
that the limestone, the whole of which stratum is composed of 
marine exuviae, is of various thickness, from four fathoms to more 
than two hundred ; beneath which, separated from the former by 
a sti’atum of toadstone, it is ascertained that there is another 
stratum of limestone, beyond which no mine in Derbyshire has 
penetrated. -f- 
Anxious to obtain all the information respecting this animal which 
I might be able, I obtained from Ashford a slab of marble, which 
had very much excited the attention of Mr. Whitehurst, and of 
several philosophical characters who had visited that part of Derbyshire ; 
it being the largest level slab, with the animal remains in relief, that 
had been there met with. This slab, almost entirely composed of these 
remains, has one surface, which is completely covered with projecting 
fragments of the vertebral column of this animal, and is four feet and 
six inches long, two feet and six inches wide, and from two to three 
inches in thickness. 
On this very considerable quantity of surface, I entertained great 
expectations that I should be able to discover some traces of the 
superior and inferior extremities of the animal ; but in this I was en- 
* Natural History of Fossils, P. 236. 
f Mineralogy of Derbyshire, P. 12. 
