132 



DISCOVERY REPORTS 



species within the eddy of Weddell Sea surface water. At the western end of the strait 

 both Coret/iroti and Rhizosolenia were comparatively scanty. 



The distribution of Thalassiosira antarctica is shown in Fig. 68. This species showed 

 a very strong maximum in the Weddell Sea eddy, and was elsewhere most numerous in 

 the extreme north-east as one would expect if the remnant of the spring increase within 

 the strait had indeed drifted off in that direction. 



The distribution of both Fragilaria antarctica (Fig. 69) and Chaetoceros neglectus 

 (Fig. 70) at the eastern end of the strait was very similar to that of Thalassiosira, except 



Fig. 70. The distribution of Chaetoceros neglectus in Bransfield Strait, December 1930. 



I = one thousand. 



that Chaetoceros neglectus was almost entirely confined to the Weddell Sea water. The 

 only exception was at St. 540 where mixing may have occurred. At this time Ch. 

 neglectus was evidently re-entering the strait in the old Bellingshausen Sea water to the 

 westward, as it was present at Sts. 550-552 in small numbers, and at St. 555 a week 

 later in considerably greater numbers. It will have been noted that the numbers of 

 Corethron present in this haul were also considerably greater, which points to the end 

 of December being the time of the beginning of the reinvasion of the Bransfield Strait 

 by phytoplankton associations from the Bellingshausen Sea, as distinct from the spring 

 increase in the old water within the strait. 



