41 o NATURAL SCIENCE. June, 



I have myself not yet seen the Nautilus swimming at the surface 

 of the sea, all my specimens having come from the bottom. 



2. Nature and Temperature of the Sea-bottom in Blanche Bay. — I have 

 dredged in Blanche Bay in nearly all directions with the assistance of 

 a small steam launch which I hired for the purpose, and everywhere, 

 apart from the reefs which occur here and there near the shore, have 

 found the bottom to consist of firm mud (which at some points is 

 consolidated to a clay) and loose pumice-stones. This, then, is the 

 feeding-ground of the Nautilus. I have not yet ascertained whether it 

 is also the breeding-ground. 



The temperature at the bottom, as found by attaching a deep-sea 

 thermometer (kindly lent by Mr. Parkinson) to a fish-basket, is 

 between 19 and 20 Celsius. This means that there is a difference of 

 some io° C. between the water in which the Nautilus lives and that 

 into which it is brought when hauled up to the surface, and may 

 account, in some measure, for the difficulty in keeping it alive for any 

 length of time. 



3. Food. — When a Nautilus, which has been taken in the fish- 

 basket, is examined, the stomach, or crop, is found to be filled to its 

 utmost capacity with fragments of the small fish used as bait. Among 

 these are fragments of small Decapod Crustacea (probably Carididae), 

 and it is probable that the latter form its chief article of food under 

 ordinary circumstances, since they also come up, sometimes in large 

 numbers, in the fish-baskets, and I have seen the Nautilus attack and 

 swallow them. Owen also found Crustacean remains in the stomach 

 of his specimen. It would seem as though they would prefer soft- 

 bodied fish if only they could catch them. Dr. Woodford informed 

 me by letter that in the Philippines the baskets in which the Nautili 

 are caught are baited with pieces of raw chicken. 



Nautilus itself affords very good eating. Not one that I capture 

 is wasted. The taste is very much like that of other Cephalopods, 

 and the toughness is between that of a young squid and an old 

 octopus. 



4. Youns; Individual. — The youngest individual that I have as yet 

 obtained was a male with the following dimensions : — 



Length from root of siphuncle to mid-anterior 



point of hood (measured along the dorsum) 25 mm. 

 Length of hood in middle line... ... ... 10-5 ,, 



Breadth of body across middle of eyes ... 15 ,, 



The surface of the hood was perfectly white and unpigmented. 

 The branchiae of opposite sides were in close apposition in the 

 median line, and, curiously enough, the larger posterior pair extended 

 forwards far into the interior of the funnel. 



The shell was perforated at the umbilicus, as it is throughout life 

 in N. umbilicatus. 



5. — Relations of male and female [N. pompilius).— Out of sixty-seven 

 individuals, fifty-one were male and sixteen female, so that the 



