DISTRIBUTION OF PHYTOPLANKTON S3 



Rh. bidens, Karsten, was recorded at five stations: 137, 161, WS 112, WS 113 and 

 WS 114. 



Rh. chunii, Karsten, was only taken at two stations: 133 and 161. 



Rh. curvo, Karsten, occurred at twelve stations being taken in the largest numbers 

 in the sub-Antarctic Zone between South Georgia and the Falkland Islands, as shown 

 in Fig. 22. At Sts. 10, 11 and 12 approaching South Georgia from Tristan da Cunha 



60° 



50° 



«?1. 



! a> 



^# 



FALKLAND Is. 



□ 



□ 



,# 





;~*^x ■ 



& 



55 



*rZSfa c 



□ < 10.000 

 D 10,000- 



I 1 50.000 

 I 1 100.000 



uSTST* 



-:or^° 



•c* 



°Rgia 



53,000 

 100.000 



60° 



50° 



35 



Fig. 22. Distribution of Rhizosolenia curva at stations between South Georgia and the Falkland Islands, 

 February 1927. The values shown at the seven points immediately around South Georgia represent average 

 values for the stations on the seven radiating lines. Negative observations shown as dots. 



in February 1926, where the N 50 V net 

 was not used, it was taken in small num- 

 bers in the N70 V net: 50, 45 and ca. 500 

 respectively. Its distribution as shown by 

 N 50 V nets is given in Appendix I. The 

 occurrence of this typically sub-Antarctic 

 species in small numbers round South 

 Georgia is interesting. 



Rh. obtusa, Hensen, has occurred irre- 

 gularly on each side of the island, being 

 taken in largest numbers at St. 161. Its 

 distribution is shown in Appendix I. 

 Since, as in the case of Rh. alata, there 

 has been confusion in the past over this 

 species, we reproduce drawings in Fig. 23 

 made from specimens taken on the survey. 



Rh. polydactylo, Castr. This diatom 

 was not taken in any of the net samples, 

 but was recorded in patches on a record 



Fig- 23. 



Rhizosolenia obtusa, Hensen, drawn from 

 specimens in the survey. 



