The South Australian Naturalist. 6? 



nected with a funnel ; when pursued the animal ejects ink into 

 the water, and this baffles the enemy. This ink has been used 

 by artists for many centuries, and is still used. The naturalist 

 Cuvier drew his illustrations of the structure of many cuttles 

 with the ink obtained from the animals themselves. The 

 mouth has a parrot-like beak, only the lower mandible is the 

 larger of the two, and the toneue (radula) is covered with 

 hundreds of tiny teeth, which help to grind up food. The 

 pearly nautilus (Nautilus pompilius) was shown, also a pic- 

 ture of the animal in its shell, and a section of the shell showing 

 the wonderful internal chambered structure. The fact that 

 the nautilus is the sole survivor of the Cephalopods, which 

 lived in ancient times, and made external shells of strange and 

 varied shape, adds additional interest to it. As the animal 

 grows it vacates one pearly chamber and makes one a little 

 larger, and when full grown has more than thirty empty rooms, 

 pierced by a tube (siphuncle), the purpose of which is not 

 clearly understood. It has nineteen tentacles, which have no 

 suckers, and as the thick shell is protection for the soft body 

 an ink bag is not needed. It lives in the warm seas. When 

 one was found on Yorke Peninsula recently much interest was 

 evinced at such a remarkable occurrence. Several species of 

 fossil Nautilus shell have been taken from the clffs at Port 

 Willunga. The "Paper nautilus'' (Argonauta ozyrata) be- 

 longs to the sub-order Octopoda, or eight-footed Cephalopods, 

 and is very unlike the pearly nautilus. The fragile shell is not 

 chambered, and is made by the female as a ''cradle" for her 

 young, which stay in it until able to start life on their own 

 account. Two of the eight arms secrete the shell and hold the 

 animal in it. This power is so unlike any possessed by other 

 Molluscs that for many years it was thought that the animal 

 found in this shell was not the maker of it, but, like the hermit 

 crab, one which used a shell as a temporary home. It lives on 

 Crustacea, and does not, as poets have said, come to the surface 

 and "spread to the wafting breeze a twofold sail." The male 

 argonaut is very small and has no shell of any kind. 



A picture of an octopus was shown, and the various parts 

 were pointed out and described. They have no shell and no 

 fins, but frequent holes in rocks, crawling by tentacles and 

 changing colour to match the rock or weed. Each tentacle 

 has over 200 suckers. Several species are found in South 

 Australia, and members were asked to look for them on reefs 

 and place one when caught in clear water, and they would be 

 ampl}^ repaid for their trouble when watching it. The female 

 lays about 40,000 eggs, and has been seen guarding and clean- 

 ing them. In Italy they are used for food, quite 150 tons 

 having been caught at one place. 



