*260 



i 



been led to make such observations as may assist in ascertaining its ori- 

 ginal nature. 



I am unacquainted with the place where these fossils are found ; but, 

 from the nature of the matrix, suspect it to be Stunsiield, in Oxfordshire. 

 The markings on the stone are so very thin, as to lead to the sup- 

 position that the fossil body has been removed, and has only left its im- 

 pression and stain on the stone. The stone itself is a lime-stone, very 

 full of Oolithes, with shells dispersed through it, exactly resembling 

 the Stunsfield stone, in which are found the teeth and palates of fish. 

 In another fossil of this kind, the markings vary so much from the pre- 

 ceding, as to render it, I think, deserving to be regarded as specifically 

 different. 



The wings of butterflies are said to have been found in a mineralized 

 state ; but this I very much doubt, suspecting that the opinion has been 

 derived from some delusive appearances. 



When you take into consideration the particular characters by which 

 the several species of the genus Cancer are marked, and the injuries 

 which the fossil animals of this genus have sustained, you will see, I trust, 

 the very great difficulty of distinguishing the species, even by those who 

 possess, what I do not, an intimate knowledge of this branch of natural 

 history, and an ample collection of both the recent and fossil objects of 

 our inquiry. 



It happens, indeed, very unfortunately, that in the fossil remains, 

 traces of the antennae, and the terminations of the hinder feet, are 

 hardly ever to be seen. The containing crust of the animal, with some 

 portions of its claws, are generally the only parts preserved ; but the in- 

 cisural and dentated markings on the sides and fore part of the former, 

 and the terminations of the latter, are very seldom discoverable. It 

 is only from the size and general forms of this kind of fossils, that we can 

 offer any opinion with respect to their species ; and, where the approxi- 

 mation of the fossil is, in this respect, near to the recent animals, but lit- 



