GREAT NAUTILUS. 
The two figures annexed, represent the shell 
of the Nautilus Major, or Great Nautilus. 
The upper figure gives it's exterior appear- 
ance ; and the under, which is the same shell 
cut open, affords a view of it's internal cham- 
bered stfudlure. Da Costa, from this struc- 
ture, calls it the Pearly-Chambered Nautilus ; 
as well as the Indian Pearly Nautilus, or Sailor. 
He defines the Nautili to be *' a genus of re- 
volved shells, the spires of which never appear 
externally, but remain latent, or quite con- 
cealed, within the body of the shell.. The 
Paper Nautilus," adds Da Costa, " though, 
classed by most authors as a Nautilus, is of a 
distin6t genus; it not being of a chambered 
stru6ture. The species of Nautili are few. 
Authors make two sortk of the East Indian or 
Pearly kind ; to wit, the Umbilicated and 
Non-Umbilicated : to which I assent. This 
Pearly Nautilus is by several authors very er- 
roneously called Nautilus Grscorum ; whereas, 
the Nautilus of the Greeks was the Paper Nau- 
tilus, not this kind." Much ingenuity has 
been displayed by various writers, to reconcile- 
errors 
