ON CRUSTACEA. 
285 
essential to their preservation ; that these mollusca, destitute 
of eyes, and of but little energy of sensation, having held their 
shell for some time open, so that the little fishes might enter 
there, were advertised, when there was a sufficient quantity, 
by a bite made by the pinnotheres; that they then closed their 
shell, and partook of the booty together. 
This opinion, however absurd, appears to have been 
entertained by the ancient Egyptians, among whom the 
symbolic representation of the pinna and the cancer de- 
signated a man or father of a family, whose existence de- 
pended only on the assistance of his children. But what- 
ever may be the source of these erroneous traditions, the 
naturalist should not the less desire to know what the ani- 
mals are which have given rise to them. Camus, in his 
Commentary on Aristotle’s History of Animals, forming the 
second volume of his French translation of this work, had 
presented on this question some very judicious reflections. 
This investigation has equally engaged the attention of M. 
Cuvier; and in his critical dissertation, the object of which is 
to ascertain the astaci, or in fact decapod Crustacea, men- 
tioned by the ancients, he has discussed, with that sagacity so 
peculiarly his own, the testimonies relative to the pinnotheres. 
Not only does he consider the history which has been given 
of them as the pure fruit of imagination, but he seems to 
think that the ancients had no very correct notion concerning 
the Crustacea which are the object of these fabulous narratives. 
It is well known, that divers Crustacea, by reason of the 
more feeble consistence of their testa, or otherwise, are in- 
stinctively impelled to choose particular domiciles, usually 
moveable, and especially shells, both univalve and bivalve. 
The pinnotheres are of this number; but they differ from 
the paguri, in inhabiting none but bivalve shells, and always 
in company with their proper owners. The same shell 
