298 A NATURALIST ON THE " CHALLENGER." 



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 down- 

 wards. Two other pairs, situate 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 animal belong- 

 ing 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 only been procured two or three times. We 

 obtained one specimen during our cruize, 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 in the New Hebrides, in this manner, in com- 

 paratively shallow water, and the animals were so taken in the 

 time of Rumphius, at the end of the seventeenth century. Traps 

 seem never to have been tried for them in deep water. 



The fact that the livincr Nautilus was obtained from 320 

 fathoms, shows that it occurs at great depths. It is probably a 

 mistake to suppose that it ever comes to the surface voluntarily 

 to swim about. It is probably only washed up by storms, when 

 injured perhaps by the waves. The living specimen obtained by 

 us seemed crippled, and unable to dive, no doubt because it had 

 been brought up so suddenly from the depths. 



The following is a translation of the account given of the 

 habits of the animal by Rumphius, whose figure of the animal, 

 as seen when taken out of the shell, is probably still the best 



