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 lime- 

 stone ; 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, ob- 

 serves, 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 stratum of toadstone, it is ascertained that there is another stra- 

 tum of limestone, beyond which no mine in Derbyshire has pene- 

 trated }% 



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 seve- 

 ral 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 su- 

 perior and inferior extremities of the animal ; but in this I was en- 



* Natural History of Fossils, p. 236. 

 f Mineralogy of Derbyshire, p. 12. 



