342 THE LIVING ANIMALS OL THE WORLD 
Photo hy W. Saville-Xcnt^ P.Z.S. 
SHELL OF THE ARGONAUT, OR 
PAPER-NAUTILUS 
The female animal only possesses a shell, and uses it as a cradle 
for her eggs and young 
usually retracted within special pouches when 
not in use, can be shot out to a length at 
least twice that of the eight ordinary arms. 
Both the cuttle-fish and the squid, or cala- 
mary, are also the possessors of an internal 
calcareous or horny shell which underlies 
and strengthens the upper-surface. The 
cuttle-bone used as a dentifrice and ink- 
eraser is the product of the first-named 
mollusc. The Ten-armed group, as it is 
named, with reference to the two supple- 
mentary arms, ten in all, possessed by its 
members, is notable for including species 
whose dimensions not only exceed those of 
any other invertebrate type, but whose fully 
extended length rivals that of the largest 
vertebrates. Giant squids, or calamaries, have 
been taken off the coast of Newfoundland, 
yielding, with their tentacular arms extended, 
a linear measurement of over 50 feet, asso- 
ciated with an estimated weight of as much 
as 1,000 lbs. There can be no doubt that 
these giant squids have in many instances 
furnished the basis of the oft-recurrent sea-serpent stories, more especially on those occasions 
where the supposed marine reptile and a whale have been reported as seen engaged in combat. 
As a matter of fact the sperm-whales habitually feed on deep-sea squids, and have been 
known, when mortally wounded, to vomit forth detached portions of these gigantic molluscs. 
The long tentacular arms of one of these monsters, thrown around the whale with which it 
had entered upon a death-struggle, might at a little distance be easily mistaken for some 
huge snake-like organism. 
The various species of NAUTILUS, including the so-called “ Paper” and “ Pearly” species, 
belong likewise to this group of Molluscs. In the former case, however, it is only the female 
animal which secretes a shell, and this is used as a cradle wherein she deposits her eggs and 
rears her young. The pretty romance of the Paper-NAUTILUS, or ARGONAUT, as it is technically 
termed, floating on the sun-lit waves with spreading sails and an even keel, has unfortunately 
been entirely dissipated by the penetrating search-light of modern science. The animal only 
floats on the surface when ill, or when torn from its customary pasture-fields by abnormal 
storms, otherwise it creeps about the sea-bottom, or disports itself in the sub-marine grottoes 
like an ordinary octopus, with which, in point of fact, the shell-less male agrees in all essential 
details. The shell-cradle of the paper-nautilus is not vitally connected with the body of the 
animal, as is that of the pearly species and all ordinary shell-fish. It is freely detachable 
from the body, and during life is grasped and held closely to it by the expanded extremities 
of the two lateral tentacles by which the delicate shell is mainly secreted. 
The ne.xt group comprises the great bulk of Simple-shelled Molluscs, of which it is 
impossible in these pages to give more than a brief enumeration of some of the most 
prominent. The Lung-breathing section, which is usually awarded the first place on the list, 
includes the familiar Garden-sn.\ils, the Shell-less Slugs, the Fresh-water Snails which 
come to the surface to breathe, and many distinct terrestrial species. The largest living repre- 
sentative of this group is the huge Land-SN.\il of tropical West Africa, sometimes known as 
the Agate-snail, the shell of which is not infrequently as much as "]\ inches long. 
The Naked-GILLED Sea-slugs constitute a second clearly defined group. All the species 
are essentially marine, and most abundant among seaweeds and coral-growths. They are 
