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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 ossiculee 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 surfaces ; 
besides which, a difference is also observable between their respective 
forms. The ossiculae of the Gloucestershire fossil are pentagonal, 
and in each articulating surface, a perfect stellated figure exists, 
differing only in its size from the star which appears on the vertebrae 
themselves. But in the Yorkshire fossils, the ossiculae are rather of 
an oval form, similar to those of the Briaraean pentacrinite, and their 
articulating surfaces are formed on the side by four small depressions, 
and on the opposite side, by four corresponding eminences. These 
differences in the forms of the ossiculae, and in their articulating surfaces 
are, doubtlessly, sufficient to separate these pentacrinites decidedly in 
two species. 
The characteristic differences which will serve to distinguish from 
each other the Briaraean, the Gloucestershire, and the Yorkshire penta- 
crinites 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 ossiculae are pentagonal, and their 
articulating surfaces are radiated and crenulated like the vertebrae 
themselves ; whilst the ossiculae in the vertebral processes of the York- 
shire, as in the Briaraean pentacrinite, are of an oval or round form, 
