DISTRIBUTION OF ANTARCTIC MACROPLANKTON 77 



Stebbing (1888): Primno macropa, Vibilia antarctica. 



Stebbing (1906): Eusirus antarcticus. 



Tattersall (1908): Euphausia superba, E. crystallorophias, E. triacantha, E. vallentini. 



Hansen (1913): Euphausia frigida. 



Massy (1920): Cleodora sulcata. 



Massy (1932): Limacina helicina, Spongiobranchaea australis. 



Bonnevie (191 3): Limacina balea. 



Eliot (1907): Clione antarctica. 



Ihle (1912): Salpa fusiform is f. aspera. 



Other species which occur from time to time, but which are mostly uncommon and 

 are disregarded here, are certain Medusae, Ctenophora, Polychaeta, Ostracoda and one 

 or two small Amphipoda. 



This method of taking only certain units into consideration might be criticized as 

 arbitrary ; but the use of any net with a particular aperture and mesh is also arbitrary, 

 and the best we can do is to study certain organisms, and find from them what we can 

 of the general behaviour of the macroplankton. 



CRUISES IN THE PERIOD 1927-31 



The following notes are not perhaps essential to the purposes of this paper, but since 

 the catches taken in the various cruises will not be dealt with in strict chronological 

 order, I have felt that a brief statement of the order in which the stations were taken 

 might be useful for occasional reference. 



During the first commission of the 'Discovery' and the associated work of the 

 ' William Scoresby ', the 1 m. nets were towed in horizontal flights of three. On the 

 return of the 'William Scoresby ' to South Georgia in February 1928, and in all subse- 

 quent work, the oblique 1 m. net (N 100 B) was used at all routine stations. The greater 

 part of the plankton work in the Antarctic has been done during the summer months 

 from October to April, and it will therefore avoid confusion if we speak of summer 

 seasons (which are equivalent to the whaling seasons) rather than of years, and say that 

 the regular work with the N 100 B began in February 1927-8. Full details of all the 

 stations carried out, together with charts, are published in the Station Lists. 1 



Season 1927-8 (Figs. 5 and 10). The work of the ' William Scoresby' began with a line of stations 

 from the Falkland Islands to South Georgia (WS 1 39-43*) and was followed by a survey of the South 

 Georgia whaling grounds (WS 144-93). A line of stations was then worked from South Georgia to 

 the vicinity of the South Shetlands and another line northwards to the Burdwood Bank and the 

 Falkland Islands (WS 196-205). 



Season 1928-9 (Figs. 6, 7, 1 1 and 15). The ship was next engaged in a trawling programme, but 

 plankton work was resumed in August 1928. After a line of stations from the Falkland Islands to 

 South Georgia (WS 253-6), the South Georgia survey was repeated, with the exception of the two 

 southern lines, in incessantly adverse weather conditions, during the end of August and the greater 



1 Discovery Reports, HI, pp. 1-132, and IV, pp. 1-230. 



2 Where a line of stations crosses the Antarctic convergence, the station numbers given here in brackets 

 include only those taken in Antarctic water together with the first station on the north side of the convergence 

 if it is still quite close to the latter. Stations at which the N 100 B was not used are omitted in the 

 charts shown in Figs. 5-17. 



