304 SUPPLEMENT 
these animals. Be this however as it may, Aristotle says, 
upon the subject, after having previously spoken of the po- 
lypi, or naked octopi, “there are yet two genera of polypi, 
but they inhabit shells; the first is named nautilus by 
some, and nauticus by others. The animal is similar to a 
polypus (octopus), and its shell has a concave cochlea, but 
the animal is not attached to it. This animal, which is 
small, usually seeks its food along the coasts; sometimes the 
waves cast it ashore, and the shell falling, it is surprized and 
dies on land. The second, which has a shell, is like the snail ; 
it does not come forth, but remains there, like the helix, 
though it sometimes stretches forth its arms out of the shell.” 
A little further he says, ‘‘ the polypus nautilus is of the nature 
of those animals which may pass for extraordinary, for it can 
float upon the sea; it rises from the bottom of the water, the 
shell being reversed, so that it may do this the more easily, 
and that the shell may be empty. But when arrived at the 
surface it turns it round again. It has between the arms a 
kind of tissue, similar to that which unites the fingers of pal- 
mipede birds, and which only differs in being much more 
slender, and of the consistence of a spider’s web. The animal 
makes use of this tissue where there is a little wind, at the 
same time letting fall, by way of helm, the arms on each side. 
On the least appearance of danger it dives into the sea, by 
filling its shell with water. As to the origin and growth of 
this shell there is nothing certain. It does not appear to be 
engendered by sexual intercourse, but to be produced like 
other shells; but yet even this is not evident, any more than 
whether the animal can live without it.” 
Pliny, at the end of his 29th chapter, book the ninth, de- 
voted to aquatic animals, speaks only of Aristotle’s first species 
of nautilus, which he says was called pompylos by some per- 
sons. That Pliny speaks of the same animal, rests, however, 
on the supposition of Gaza, that we must read in Aristotle 
