purple tinge, as fifliing-hooks ; but when very highly magnified, are feen to have 
fome transparency, like amber, and grooves in their fides ; and have therefore a 
ftriking refemblance to the quills of the procupine, as G g. 
But there is yet another Angularity in this wonderful claw, that mayftill requir L 
a more particular illuftration. When the feet are diffe&ed, in the middle of each 
there is found a tubular fpine, of a bright yellow, like fine brafs, and femi-tranf' 
parent. With this tubular fpine, reprefented at F, the other folid ones are con- 
nected by cartilaginous fubftances, which fpread as mufcular fibres into the bod)' 
of the animal. 
The fpines of the central claw are the whole length of the tubular one, unit‘d 
at the end ; but the others fpring from a joint in the middle, as pointed out afi k 
of E and F. On the fkin, without this joint, is placed the fpur d d. 
1 - 
It is probable that the cavity of the tubular fpine may be a conveyance throug 11 
which Nature has appointed it to extract juices from thofe fubftances which lC 
can penetrate with its fpines ; for a wonderful ceconomy is obfervable in the ftruC' 
ture of that implement. But their manner of life is fo reluctantly practifed, whe* 1 
they fuffer all the inconveniencies of change of pafture and climate, which they 
muft do ere they come under human inflection, that it is no wonder we Ihould be 
fometimes at a lofs to determine the ufe and importance of their furprifing 
culties. 
The above may appear too minute an inveftigation of the foot of a fea-wornn \> 
but it is thefe minutiae in the ftructure of marine bodies which remains to be d»' 
dofed. 
