UNIVALVES, 151 
Nautilus was not only supposed by the ancients to 
feed on the eggs of the halcyon, or kingfisher, but 
that the appearance of these birds upon the water 
was considered a favourable omen, and thus Silenza 
propitiates the goddess, that she may be indulged 
with the sight of them during her voyage. 
The shells of the genus Argonauta, or Paper- 
sailor, are nearly as extraordinary in their appear- 
ance and formation as those of their relative the 
Nautilus, and in these we observe the same extra- 
ordinary configuration, the same subserviency to 
an evident design. They are remarkable for ex- 
cessive thinness and brittleness, and are perhaps 
surpassed by none in the delicacy and elegance of 
their construction. The form resembles that of a 
scroll, with a very large aperture; and the surface is 
ornamented with numerous channelled grooves, which 
extend from the summit to the outer margin, while 
the colour of the shells is commonly a bluish or 
dingy white, relieved by the delicate brown tinting 
of the keel. Argonautz differ considerably in size 
and value. <A few of the most curious are produced 
at the Cape of Good Hope, Mediterranean, and Indian 
Ocean; whilst others are commonly found in the 
Atlantic, Northern, and Greenland seas. 
This interesting genus, the Nautilus of Pliny, has 
been separated from the Chambered genus, bearing 
