332 
MOLLUSCS. 
surface of the water with the coiled part of the shell upwards, a small portion being 
above the surface, to which the aperture was at right angles or inclined at an angle 
of 45 c 
It appeared calm and not subject to agitation like the octopus. It 
remained perfectly immovable, for no menace or 
excitement appeared to affect this appearance 
of tranquillity. Like the octopus, it exhibited 
chameleon-like changes of the skin, but not so 
rapidly or with such intensity as that animal. 
During all the time the specimen lived, all the 
arms, which have two rows of suckers, were 
kept within the shell, except the expanded 
posterior median pair. These, however, were 
also sometimes drawn within. Four of the 
arms were bent upwards, four downwards, 
leaving the mouth with its parrot-like beak 
exposed in the middle of their bases. Between 
the lower or ventral pair of arms the funnel was 
protruded, by means of which it propelled 
itself backwards. This specimen was not seen 
either to walk or swim with its arms; but 
other observers state that the creature walks 
crawls along the bottom like a gastropod, 
SHELL OF FEMALE ARGONAUT. 
or 
The 
eye 
by means of the non-expanded arms, carrying the shell above its body, 
is round, bordered with black, and the circular pupil is also black. 
The shell is supposed to be secreted chiefly by the palmate arms, aided by the 
mantle investing the body. It is developed some time after the birth of the argonaut, 
and a female has never been seen with a shell before it had attained about an 
inch in length. The male argonaut is very different to the female, and much 
smaller, being only about an inch in length. It resembles an ordinary octopus in 
having neither palmate arms nor shell. The arms are tapering and alike, excepting 
the third on the left side, which is specialised. This at certain times, having 
passed through various stages of development, is cast off, and attaches itself to the 
female, living a free and independent life for a considerable period. The eggs are 
small, numerous, and connected together by a network of filaments. They are 
deposited far within the shell towards the convoluted portion, and are practically 
in contact with the posterior part of the body of the parent. The shell therefore 
serves, not only as a retreat for the argonaut herself, but also as a nest for the eggs, 
and possibly as a nursery for the young. Very little is known with regard to the 
food of the argonaut. As its habits are very similar to those of the octopus, it 
seems probable that it may feed upon molluscs and crustaceans, which it might 
capture when crawling at the bottom of the sea. A captive specimen was fed with 
small live fish, which it ate with avidity. About eight species are recognised, 
which have a world-wide distribution, occurring in all tropical and warm latitudes. 
The shells of the different species are all of a white colour, and exhibit two distinct 
types of surface ornamentation, the one consisting of simple, smooth, radiating 
wavy ribs, the other in which these ribs are more or less broken up into nodules or 
