184 NATURAL HISTORY. 



[Shells in this state are believed to have lost their true coloured shell-layer by the solvent action 

 of the gastric juice of the Dolphin's stomach, from which most, if not all, of the young shells of the 

 Pearly Nautilus are usually obtained by collectors.] 



" The Nautilus is found in all the Moluccan Islands, and also around the Thousand Islands off 

 Batavia, in Java, yet mostly only the empty shells are met with, for the animal is seldom found unless 

 it creeps into the lobster-pots. The animal is used for eating, like other ' Sea-cats ' ; but it is 

 somewhat harder in flesh and more difficult of digestion. The shell is in much greater request for 

 the manufacture of the beautiful drinking vessels so well known in Europe." 



Dr. Bennett says that the natives of New Holland dive for Nautilus macromphalus, and also take 

 it in fish-falls baited with an Echinus, whilst the Fijians trap Nautilus pompiliiis with a " Bock- 

 lobster " for bait. 



Mr. Moseley * writes : " In dredging off Matuku Island, in 320 fathoms, on a coral bottom, 

 some Phorus, Turrltellce, and a few other shells were brought up, as well as numerous specimens of 

 the blind crustacean Polycheles and other animals, showing the fauna to be a true deep-water one, 

 and with these a living specimen of the Pearly Nautilus (Nautilus pompUius). This was the only 

 specimen obtained during the voyage of the Challenger of this animal, so rarely seen in the living 

 condition by any naturalist. 



" The animal was very lively, though probably not so lively as it would have been if it had been 

 obtained from a less depth, the sudden change of pressure having, no doubt, very much disarranged its 

 economy. It, however, swam round and round a shallow tub in which it was placed, moving after 

 the manner of all Cephalopods, backwards : that is, with a small portion of the top of the shell just 

 out of the water, as observed by Rumphius. The shell was maintained with its major plane in a 

 vertical position, and its mouth directed upwards. 



" The animal seemed unable to sink, and the floating of the shell as described, no doubt, was due 

 to some expansion of gas in the interior, occasioned by diminished pressure. The animal moved 

 backwards slowly by a succession of small jerks, the propelling spouts from the siphon being directed 

 somewhat downwards, so that the shell was rotated a little at each stroke upon its axis, and the 

 slightly greater area of it raised above the surface of the water. Occasionally, when the animal was 

 frightened or touched, it made a sort of dash, by squirting out the water from its siphon with more 

 than usual violence, so as to cause a strong eddy on the surface of the water. 



" On either side of the base of the membranous operculum-like headfold, which when the animal 

 is retracted entirely closes the mouth of the shell, the fold of mantle closing the gill-cavity was to be 

 seen rising and falling, with a regular pulsating motion, as the animal in breathing took in the water 

 to be expelled by the siphon. The tentacular-like arms contrast strongly with those of most other 

 Cephalopods, because of their extreme pi'oportional slightness, and also their shortness, though they 

 are not shorter proportionately than those of the living Sepia. They are held by the animal, whilst 

 swimming, extended radially from the head, somewhat like the tentacles in a Sea Anemone ; but 

 each pair has its definite and different direction, which is constantly maintained. This direction of 

 the many pairs of tentacles at constant but different angles from the head is the most striking 

 feature to be observed in the living Nautilus. Thus one pair of tentacles was held pointing directly 

 downwards. Two other pairs, situated just before and behind the eyes, were held projecting obliquely 

 outwards and forwards and backwards respectively, as if to protect the organs of sight. In a somewhat 

 corresponding manner, the tentacular arms of the common Cuttle-fish, whilst living, are maintained 

 in a marked and definite attitude, as may be observed in any aquarium. 



" The very great abundance of the shells of the Pearly Nautilus is most strangely contrasted with 

 the rarity of the animals belonging to them. The circumstance is, no doubt, due to the fact that the 

 animal is mostly an inhabitant of' deep water. The shells of Spirula similarly occur in countless 

 numbers on tropical beaches, yet the animal has been procured only two or three times. We obtained 

 one specimen during our cruise, which had evidently been vomited from the stomach of a fish. 

 I expect that both Nautilus and Spirula might be obtained in some numbers if traps, constructed 

 like lobster-pots and baited, were set in deep water off the coasts where they abound in from 100 to 

 200 fathoms. Nautilus is occasionally caught, both at Fiji and the New Hebrides, in this manner,. 

 * H. N. Moseley, F.R.S. : "Notes by a Naturalist on H.M.S. Challcnr/ci;" pp. 296300. 



