6o 



DISCOVERY REPORTS 



locality in February of the preceding year. Thus it is just possible that the comparatively 

 rich occurrence of this species around South Georgia in February 1930 was due to the 

 overflow, as it were, from an earlier maximum down towards the Bellingshausen Sea 

 itself. The fact that these hauls were obtained to the east of the island does not detract 

 from this, as there was little phytoplankton in the Bellingshausen water to the west, so 

 that the mixing with eastern Weddell Sea water may well have brought out the last 



Fig. 29. The distribution of Rhizosolenia styliformis, South Georgia survey, November 1930. i = one 



hundred thousand. 



resources of this surface water. On this survey, it will be remembered, the western 

 Weddell Sea current was apparently at a minimum, and was almost certainly dissi- 

 pated before it reached South Georgia, and all the surface water round South Georgia 

 at that time was comparatively " old " and mixed. More recently Mr John's preliminary 

 investigations of samples collected during 193 1-2 confirm the possibility of Thalassio- 

 thrix being transported to the neighbourhood of South Georgia in old surface water 

 of Bellingshausen Sea origin. 

 The next species in order of total abundance on the November 1930 survey was 



