UNIVALVES — NAUTILUS. 81 
NAUTILUS.— PEARLY SAILor. 
DESCRIPTION OF PLATE XIX. 
Drv. I.—Fig. 1. N. scrobiculatus Div.I.—Fig. 2, N. pompilius. 
Du. Il.—Fig. 3. N. spirula. 
Shell univalve, divided into several chambers, communicating with 
each other by an aperture. 
THE species of the Nautilus strongly resemble each 
other in structure, and have usually a dingy white color, 
with yellow markings. The most striking character of 
the genus is, that the whorls are divided into separate 
compartments or chambers, which are connected by a 
slender syphon, running spirally through the shell. 
The syphon is sometimes central and sometimes contl- 
ruous to the surface. 
The general form of the Nautilus is spiral or scroll- 
ike, which is particularly exemplified in the shells of the 
‘st and second division: but in the third, the species are 
nical or dentiform, and bear some resemblance to the 
ntalia. The whorls are contiguous in the species of 
first division, and detached or separated in those of 
second and third. 
The N. pompilius, when bisected, displays the pearly 
ncamerations for which the genus is celebrated. Fine 
ecimens of this species are often converted by the 
habitants of the East into drinkmg cups, om the 
irface of which they engrave various devices and 
rnaments; they also frequently remove the outer coat- 
ing entirely, by which the beautiful pearly appearance 
ie the shell becomes visible. 
G 
