adhered; and on the thirty-first, the uppermost, not only these marks 

 <are observable on three of its sides ; but on one side the first ossicula 

 of the articulated process is seen, and on the other surface five of 

 these ossiculae, two of which are still adherents to their original place 

 of attachment, and the three which have slid off from the* others, are 

 remaining close by their side. 



On carefully examining and comparing together the ossiculae of dif- 

 ferent articulated vertebral processes, I discovered an unexpected 

 and important difference between those of the Gloucestershire pen- 

 tacrinite and those which I conjecture to have belonged to the York- 

 shire pentacrinite. This difference exists in their articulating sur- 

 faces ; besides which, a difference is also observable between their re- 

 spective forms. The ossicula of the Gloucestershire fossil are penta- 

 gonal, and in each articulating surface, a perfect stellated figure ex- 

 ists, differing only in its size from the star which appears on the ver- 

 tebrae themselves. But in the Yorkshire fossils, the ossiculae are ra- 

 ther of an oval form, similar to those of the Briaraean pentacrinite, 

 and their articulating surfaces are formed on the side by four small de- 

 pressions, and on the opposite side, by four corresponding eminences. 

 These differences in the forms of the ossiculae, and in their articulat- 

 ing surfaces are, doubtlessly, sufficient to separate these pentacri- 

 nites decidedly in two species. 



The characteristic differences which will serve to distinguish from 

 each other the Briaraean, the Gloucestershire, and the Yorkshire pen- 

 tacrinites appear to be these. The Briaraean has its vertebral processes 

 given off from every vertebrae, whilst, in the Gloucestershire and 

 Yorkshire fossil, they are given off from distant vertebrae. In the 

 Gloucestershire pentacrinite, the ossicula? are pentagonal, and their 

 articulating surfaces are radiated and crenulated like the vertebrae 

 themselves ; whilst the ossiculse in the vertebral processes of the York- 

 shire, as in the Briaraean pentacrinite, are of an oval or round form, 



