66 



DISCOVERY REPORTS 



the waters immediately surrounding South Georgia; and the region between South 

 Georgia and the Falkland Islands. 



Region north-east of South Georgia 



At the four stations in this region: Sts. 9-12, taken in February 1926 (see Fig. 11), 

 only the N 70 V nets were used. These were taken at the following depths: 50-0 m., 

 100-50 m., 250-100 m., and 500-250 m. The phytoplankton recorded is tabulated in 

 Table III. 



Table III 



No information can be gathered as to the smaller species present. The main feature 

 of interest is the mass of Thalassiothrix antarctica at St. 12. Between this station and 

 South Georgia the Continuous Plankton Recorder revealed dense zones of this diatom ; 

 a graphic representation of this record is shown on p. 284. 



The absence of the larger forms: Coscinodiscas bouvet, Thalassiosira antarctica, 

 Corethron valdiviae, Chaetoceros criophilum and Dactyliosolen spp. is noteworthy, for, if 

 present, some at any rate of the last four and all of the first named should have been 

 taken by the N 70 V nets. The line of the Antarctic Convergence separating the waters 

 of the Antarctic from the sub-Antarctic Zone lies between Sts. 10 and 11. The great 

 production of Thalassiothrix antarctica at St. 12 contrasts with the poverty of phyto- 

 plankton towards and across the Convergence. A similar diminution in production is 

 seen on the line between South Georgia and the Falkland Islands as the Convergence 

 is approached and crossed ; this will be presently described. 



The waters surrounding South. Georgia 



We have seen that the waters in the immediate neighbourhood of South Georgia have 

 been sampled as follows : 



March, 1926, off the north-east coast, 



November, 1926, off the north-east coast, 



December-January, 1926-7, around the whole island, and May, 1927, off the north- 

 east coast. 



