44 



similar in its substance to belemnites; and having thereby established the 

 position of Klein, that every body possessing a similar structure with the 

 belemnite is not therefore to be considered as one of those fossils, we 

 are absolutely left without any distinctive character, by which, in many 

 instances, these fossils can be separated. It is true, that we sometimes 

 have, on the one hand, as in the specimen just spoken of, not only 

 the articulating termination, but so much of the colpur and surface 

 preserved, as determines its echinital origin ; and, on the other hand, 

 we have the concamerated shell, or the alveola, which contained it, 

 evincing the fossil to be a belemnite. But much more frequently 

 we meet with fossils, in which, from having been broken, rubbed 

 down, or otherwise injured, these parts are entirely removed, and their 

 figure so altered, that it is no longer possible to determine in which 

 class of fossils they are to be placed. The discovery of this speci- 

 men induced me to examine, with more care, those fossils in my 

 possession, which had been hitherto regarded as belemnites; and I was 

 much pleased at soon perceiving that many, which I should before, with- 

 out hesitation, have termed belemnites, were in all probability spines 

 of echini. In three specimens, this origin was indubitable. Plate IV. 

 Fig. 4, shows a hard and heavy spathose specimen ; which although, 

 from its form, I had often suspected to be a fossil sudes, 1 never could 

 before assert it, in contradiction to the opposite opinion of many very 

 excellent fossilists. Its triquetral form, extending through three fourths 

 of its length, and insensibly gliding into the rounded conical termina- 

 tion, with something more than a fancied resemblance in colour, deter- 

 mined it, in my opinion, to have been originally an echinital spine, 

 although the further proof of its articulating termination is, by accident, 

 destroyed. Plate IV. Fig. 19, represents a small specimen, in chalk, 

 which appears to be a fossil spine of the same species with the preceding, 

 but more rounded and fusiform : a small annular mark, at one end, 

 shows, indisputably, its point of articulation. 



The spine, . Plate IV. Fig. 14, hitherto supposed to be a belemnite, ii 



