200 THE VOYAGE OF H.M.S. CHALLENGER. 



retracted, entirely closes the mouth of the shell, the fold of the 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, which was afterwards expelled through the siphon. The 

 tentacle-like arms contrast strongly with those of most other Cephalopods, because of their 

 relatively extreme slightness and 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 oro'ans 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. Another living Nautilus was brought to the Consul at 

 Kandavii during the stay of the Challenger. The natives were said to frequently catch 

 them alive, and to give them to their chiefs, who eat thcm."^ 



1 Narr. Chall. Exp., vol. i. pp. 490, 491. 



