109 



the basis of the fossil, depicted Plate X. Fig. 5. Its general form and 

 tuberculated surface, with the risings and depressions passing from one- 

 end to the other, give it an appearance so much resembling a cucum- 

 ber, that, in the minds of those who were not a little conversant in 

 these inquiries, suspicions might arise, that it owed its- form to that 

 fruit. 



By rubbing a part of it at one of its terminations with a sand- stone, I 

 ascertained that it was hollow, and that the substance of the fossil 

 was about a third of an inch in thickness. On examining this fos- 

 sil, by attrition on different substances^ and in various other ways r 

 it was discovered to he composed of a loose, spongy, calcareous mat- 

 ter, combined with a very small portion of siliceous sand, and incapa- 

 ble of acquiring a polish. On several parts of its ashen grey-coloured 

 tuberculated surface, patches of a thin pellicle, of .a reddish yellow 

 cast, were discoverable ; and the magnifying lens shewed that a de- 

 pression, and even an opening, were observable in the centre of some 

 of the tubercles. At one end, which in the plate I have made the 

 superior, no imperfection appears ; but at the other end a surface is 

 observable, from which, it seems, that a part has been broken off; 

 and on that surface the lenSj demonstrates strong marks of organi- 

 zation. 



From the texture of the fossil itself, and from the appearances at 

 its inferior termination, the cellular, spongy, organized original 

 body may be inferred; and from the apparent fracture at the same 

 termination, the existence of a pedicle at that part may be supposed. 

 Additional reasons for supposing it to have been organized, in a man- 

 ner similar to alcyonia, may be deduced from the openings, observa- 

 ble in some of the tubercular risings, and in the thin cortical part, the 

 remains of which are so distinctly to be seen. 



But the circumstance which serves most of all to corroboratethia 

 opinion respecting its origin is, that Count de Marsilli describes a re- 

 cent alcyonium, which agrees in. all its essential characters with tlii* 



