696 DREDGING IN BLANCHE BAY. 



can be made out under a microscope or simple lens. I have given sketches of the 

 Tornaria (larva of Enteropneusta), which I obtained in the New Britain Plankton in 

 Part in. (p. 286) of this publication. Among many other objects, a small pelagic 

 Mollusc known as Atlanta, belonging to the sub-order Heteropoda, was abundant at 

 various depths. It was my first acquaintance with this small creature which is almost 

 absurdly like a miniature Nautilus. It possesses in fact a perfect involute planorbiform 

 shell, laterally compressed, symmetrical on both sides 1 and not exceeding 5 millimetres 

 in major diameter. Of course it differs essentially from Nautilus in that the cavity 

 of the shell is not divided into chambers and the orifice is directed downwards, 

 i.e., towards the back of the animal. 



Another frequent component of the Plankton consisted of the Appendiculariae, 

 small pelagic. Ascidians which permanently retain a caudal appendage only present 

 during the larval phase in the life-history of the fixed Tunicata. I was somewhat 

 surprised to find specimens of a bright yellow colour and others brilliant blue, not 

 knowing previously that these pellucid animals ever possessed any pigmentation. It 

 has, however, recently been noted by Mr E. T. Browne that specimens of the genus 

 Oikopleura occurring in British waters are sometimes coloured a bright crimson 2 . 



More important than these Plankton excursions, which generally took place in the 

 small hours of the morning before sunrise, was the investigation of the nature of 

 the ground at the bottom of the sea in Blanche Bay. This revealed the existence 

 of submarine chasms probably inaccessible to the dredge, and it may be at once noted 

 as a possibility that such protected situations are naturally chosen by Nautilus for the 

 purposes of nidification and oviposition. 



In order to clinch matters at the outset I seized the opportunity of engaging, 

 by favour of Herr Thiel, the representative of the firm of Messrs Hernsheim and 

 Company on the island of Matupi in Blanche Bay, the services of a small steam- 

 launch, the only one in the Archipelago. With the kind permission of Mr Adam 

 Sedgwick I had taken out with me from Cambridge a couple of drums of wire-rope, 

 and one of these was fixed upon thwarts on the launch. Eventually I came to the 

 conclusion that, when dredging from light craft in moderate depths, ordinary strong 

 hemp rope is to be preferred. A pair of gun-metal bollards were screwed on to the 

 stern of the vessel for the rope to pass over when hauling in, since, without these, 

 the wire would cut through Australian hard wood with the greatest ease. The depth 

 varied from thirty to seventy fathoms and there is no doubt that the result of these 

 laborious dredgings was not very encouraging. They simply proved (apart from the 

 chasms mentioned above) that the ground on which Nautilus is caught in the fish-baskets 

 is essentially composed of volcanic mud and pumice stones. 



While staying at various places about Blanche Bay my food, besides tinned stuffs 

 and an occasional fish, consisted principally of yams in the north-west season and taro 

 during the south-east monsoon. These invaluable tubers and corms are purchased from 

 the women at the markets which they hold periodically on the beach. They bring 



1 Not in all species, ef. Souleyet's figures in the Atlas of Voyage ale. la Bonite, 1836 — 1837. 

 " " The Fauna and Flora of Valeucia Harbour," P. Irish. Ac. (3), v. p. 751, 1900. 



