CHAPTER III. 
DESCRIPTION OF PLATES. 
Amongst the best known shells in any part of the world the 
Nautilus takes a leading position. Named Argonauta by scientific 
men, after the Argonautae, or sailors of the Argo, it has been the 
subject of many legends from the earliest times. Aristotle de- 
scribes it as floating on the surface of the sea in fine weather, and 
holding out its sail-shaped arms to the breeze. This is now known 
to be incorrect, as the use it makes of these arms is to help it 
in swimming through the water. New Zealand’s specimen, the 
Argonauta nodosa, also known as Argonauta argo, the most beauti- 
ful of the four known species, is depicted on Plate I. Being a 
floating shell, and found even hundreds of miles from land, our 
Nautilus is not peculiar to New Zealand. Its beautiful white, 
horny-looking shell can be obtained from most parts of the Pacific 
and Indian Oceans, but in no part of the world can finer specimens 
than ours be found. It is known to the Maoris as Muheke or Ngu, 
and colloquially as the Paper Nautilus. 
The animal that produces this shell belongs to the octopus, 
or cuttlefish, family. The male is an insignificant-looking octopus, 
about an inch long. The female grows many times larger, as can 
be imagined from a glance at the shell in the plate, which measured 
nine inches across, and was found at Mayor Island, in the Bay of 
Plenty, and is now in the possession of Mr. C. Spencer. 
In the shell the female lays her eggs, and in it the young are 
hatched. Unlike all other shells, the Nautilus is not moulded on 
the animal, nor is she even attached to her shell by muscles. When 
washed ashore she can wriggle out of her shell and swim away. In 
her shell she lies as in a boat, propelling herself by slowly sucking 
up water, and violently ejecting it through a funnel, or syphon, at 
the same time using her arms as oars, to increase her speed. Dame 
Nautilus can sink to the bottom of the sea if she chooses; and when 
wishing to crawl about the sand or rocks she turns over and carries 
her shell on her back, like a snail. 
