8 ON A ZOOLO&ICAL EXPEDITION TO THE SOUTH SEAS. [Jail. 17, 



but I captured four specimens of Ctenoplana ', which yielded a 

 number of results of some interest. This remarkable form, half 

 Ctenophore and half Plathelminth, had previously only been 

 obtained as a unique specimen by the Russian naturalist Korotneff, 

 off the west coast of Sumatra in 1886. Korotneff's account was 

 inaccurate in many details, and his discovery of the type was 

 regarded with some scepticism. My re-discovery of this creature 

 is therefore matter of satisfaction. All four specimens were 

 taken from a drifting cuttle-bone off the Conflict Lagoon in the 

 Louisiades, British New Guinea. 



From the Deboyne Lagoon, in the same Archipelago, I obtained 

 a species of Ampliio.vus belonging to the subgenus Asi/mmftron, 

 previously known only from the West Indies. This is a remark- 

 able fact of distribution, since in the Torres Straits, v\hich are 

 comparatively close by, there are two species of Amphioxus 

 belonging to other subgenera. 



W^hen I revisited New Guinea on my return for the second time 

 to New Britain, I was fortunate in securing the only specimen ever 

 seen of the animal of Nautilus umhilicatus, which had been taken 

 from the surface off the East Cape of British New Guinea. 

 Nautilus does not come to the surface normally according to my 

 observations, and all specimens which are taken from the surface 

 are probably in a moribund condition. This was the case with the 

 specimen obtained by Dr. Bennett, upon which Sir Richard Owen 

 based his classical work on Nautilus. 



My object in changing my locality from time to time was for 

 the purpose of finding a place where Nautilus could be more 

 easily got at. After much misgiving and disappointment, I at last 

 found such a place — namely, Sandal Bay, Lif'u, in the Loyalty 

 Group. In this place Nautilus migrates at night from deep water 

 into as little as three fathoms. It comes quite close to the shore. 

 The species occurring here is N. macromj^halus. So far as I have 

 ascertained at present, this species only differs from N. j)ompiUus 

 in the character of the umbilicus of the shell. The animals are 

 almost identical. N. umbilicatus differs strikingly in external 

 appearance from both of the preceding. After an absence from 

 England exceeding two years, I induced Nautibis to deposit its 

 eggs in my cages. The eggs are firmly fixed to a suitable surface : 

 the best artificial surface which can be offered to the Nautilus is 

 sacking, the fibres of which are entangled in the hardened milk- 

 white capsule of the egg. I have described these eggs in the ' Pro- 

 ceedings of the Royal Society ' (1897). Neither in Lifu nor 

 subsequently in New Britain, where I got the eggs of N. jjompilius, 

 was I able to rear embryos from the deposited eggs — such was the 

 effect of captivity. 



The geographical distribution of N. macromplialus is interesting. 

 It is confined rigidly to the New Caledonian Archipelago. In the 

 neighbouring New Hebrides and in Fiji, N. pompUius is again met 

 with. 



^ See Q. J. M. S. vol. xxxix. 1896, p. 323. 



