DISTRIBUTION OF PHYTOPLANKTON 6? 



It will be convenient to discuss the distribution of the plankton in seasonal order- 

 starting in the spring with the stations taken on the C line in November 1926, i.e. 

 WS 18-22. The N 50 V nets unfortunately were not used on this line; but we can gain 

 a slight knowledge of the larger forms of the phytoplankton present from the N 70 V 

 nets, the analyses of which are tabulated in Table IV. The most important form present 



Table IV 



Distribution of phytoplankton as shown by N 70 V nets, Sts. WS 18-22. 



November 26-30, 1926 



* Sufficient depth for the haul, 1000-750 m., was only obtained at St. 22; the black line represents 

 diagrammatically the sea bottom at the shallower stations. 



on the line as a whole is Thalassiosira antarctica; but at St. 20, in the middle of the line, 

 a very dense and isolated patch of Chaetoceros socialis was recorded both from the 

 50-0 m. and 100-50 m. hauls. This diatom, whilst individually small, forms large masses 

 of interlocking chains, and so is able to be caught by this net. The numbers given here, 

 except for Coscinodiscus bouvet, which is fairly sampled by this net, are a mere indication 

 that these diatoms are present in really much larger numbers. See note on Thalassiosira 

 antarctica, on p. 49. 



Passing now to the main December-January 1926-7 survey, we are here dealing with 



