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The echinital spines which are found in chalk, are known by 

 the chalk-diggers by the names of files, and chalk bottles : by the 

 former, are meant the striated and prolonged cucurmerine clavicula; and 

 by the latter, those which are of an olive form. The belemnites have 

 also, from early times, been distinguished by them as pencils. About 

 two years since, among the chalk fossils which I had obtained from 

 Kent, were several pencils ; and among them one, which, when cleared 

 of the chalk, and carefully examined with a lens, I could plainly per- 

 ceive was not only not a belemnite, but a complete palisadoe-spine, 

 possessing a perfect circular articulating cavity, and a grained surface, 

 somewhat resembling the manufactured surface of seal-skin. Like most 

 of the recent spines of this genus, it is of a triquetral form, at the end 

 which is attached to the shell : but, unlike all those figured by Klein, it 

 not only soon becomes larger and rounded, but terminates in a rounded 

 cone. Its colour, at its articulating end, is of a very light fawn colour, 

 which shades off to nearly white, at about one third of the length of the 

 spine, the remaining part being again of a fawn colour, but much darker 

 than that in the other part of the spine. 



As a collector, I highly estimated a fossil, which I had not hitherto 

 known to exist, and consequently treasured it with some care. But 

 comparison with some specimens of the Folkstone belemnites, which 

 possess somewhat of a similar form with that of this fossil, and at the 

 same time the transparency of the Prussian fossils, which, although 

 generally regarded as belemnites, had been suspected by Klein to be 

 echinital spines, induced me to suspect a similarity of substance in both 

 fossils. To determine this, I broke the fossil spine in two, and was 

 astonished to find its substance exactly agreeing with that which is con- 

 stantly found in belemnites : a dark brown spar, with striae radiating 

 from the centre, and intersected by concentric circles. 



Having thus got rid of this erroneously assumed mark of distinc- 

 tion, the brown radiating spar, and ascertained that a body, indis- 

 putably an echinital spine, had, by its mineralization, been rendered 



