34. 



THE LIVING ANIMALS OF THE WORLD 



Phtila by ly, Sa^illi-Kinl, F.Z.S. 



SHELL OF THE ARGONAUT, OR 

 PAPER-NAUTILUS 



The female animal only poiseises a shelly and uses it as a cradle 

 Jor her eggs an J young 



usiiall}' retracted within special pouches wlien 

 not in use, can be shot out to a length at 

 least twice that of the eight ordinary arms. 

 Hcith the cuttle-fish and the squid, or cala- 

 inar}-, are also the possessors of an internal 

 calcareous or horny shell which underlies 

 and strengtiicns 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- 

 mentar)' arms, ten in all, possessed by its 

 members, is notable for including species 

 whose dimensions not only e.xceed those of 

 an\- other invertebrate type, but whose fully 

 extended length rivals that of the largest 

 vertebrates. Giant squids, or calamarics, ha\'e 

 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 \'omit 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 P.-VPER-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 b>- 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 ordinar\- 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 pearl}- species and all ordinarj- shell-fish. It is freely detachable 

 from the body, and diu'ing life is grasped and held closeK" to it by the expanded extremities 

 of the two lateral tentacles by which the delicate shell is mainly secreted. 



The next 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 Gakdex-sxah.s, the Shell-less SLUGS, the Fresh-\v.\ter Snails which 

 come to the surface to breathe, and man\- distinct terrestrial species. The largest living repre- 

 sentative of this group is the huge Land-snail of tropical West Africa, sometimes known as 

 the Agate-snail, the shell of which is not infrequently as much as 7.I inches long. 



The Naked-GILLED Se.\-SLUGS constitute a second clearly defined group. All the species 

 are essentially marine, and most abundant among seaweeds and coral-growths. The\- are 



