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ossiculae enter into the formation of some of the upper and shorter ; 
and between thirty and forty, in some of the lower and longer ten- 
tacula. Rosinus, whose accuracy cannot be spoken of in terms too 
high, remarks, that in all the ossiculae of which the pelvis, arms, and 
fingers are formed, foramina, or sinuses, are observable, fitted for the 
reception of nerves or vessels. Every examination which I have been 
able to make confirms these remarks ; and by examination with a 
lens of moderate power, of a longitudinal polished section of the ar- 
ticulated tentacula themselves, I found that all their ossiculae are 
nearly tubular, having a cavity, which is nearly cylindrical, passing 
through their substance. That these cavities served for the transmis- 
sion of nerves and vessels is highly probable ; but it appears to be also 
very likely that the muscular parts also passed through these cavi- 
ties ; this disposition of the muscles appearing to be such as would 
fully admit of the performance of those motions, on which the exist- 
ence of the animal depended. 
A longitudinal section also shewed that these tentacula, when con- 
tracted, are disposed with great regularity side by side, their smaller 
ends laying towards the upper part of the closed fingers ; and by the 
transverse section I perceived, that in consequence of grooves running 
along the inner sides of each tentaculum, they became, whilst closed, 
exactly nitched into each other, so as to give the appearance, in 
their transverse section, of the mutual insertion of the teeth of two 
saws. * 
Rosinus had remarked that these tentacula commenced where the 
rays or arms began to divide ; but by the polished longitudinal sec- 
tion just referred to, I was enabled to ascertain, that these tentacula 
exist even at the very commencement of the arms. 
A careful examination ascertains the curious fact, that, indepen- 
dent of the number of pieces which may be contained in the verte- 
bral column, and which, from its probable great length, may be very 
