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upper part, is exceedingly perfect ; and at its lower end, or point, part 

 of its pedicle remains, which appears to have been remarkably small. 



Its external surface is marked by very strong alternate risings and 

 depressions, passing round it. Its texture, on this surface, appears to 

 have been very close and without any openings, except the very mi- 

 nute foramina resulting from a spongeous texture, so fine as to ap- 

 proach to the membraneous, and a few winding openings, apparently 

 the labour of some invading insect. The internal surface differs very 

 much from the external, being so remarkably smooth and regular as 

 to have the appearance of the pile of velvet. On being viewed with 

 a lens, it is seen that the villous appearance is produced by the infi- 

 nite number of minute openings arranged as close by each other as 

 possible over the whole surface. It is of a light brown, or buff colour, 

 and appears to have much less silex enter into its composition than in 

 that of the two last described fossils. Previously to passing to the 

 consideration of the next fossil, I must call your attention to the ob- 

 vious difference of structure between these fossils and those which are 

 represented, Hate VIII. Fig. 5, and Plate XI. Fig. 7, and which 

 possess somewhat of a similar form. This circumstance is also ob- 

 servable in the fossil we shall next examine. 



This fossil, represented in the frontispiece, was found in Wiltshire, 

 and was originally in the collection of the Marquis of Donegal. At 

 its inferior termination, several processes are given off, which, 

 though broken, have much the appearance of the roots of a vegeta- 

 ble : an appearance, which is, however, much more similar in another 

 specimen. From the union of these, a narrow and nearly cylindrical 

 neck is formed, which, gradually enlarging, forms a conical cup-like 

 body, the sides of which are about the third of an inch in thickness, 

 but become much thinner at their edge. From the root-like pro- 

 cesses several fibres or tubuli originate, which, ramifying, pass along 

 or penetrate the surface, in a direction tending towards its superior 

 part. 



