DISTRIBUTION 25 



The detailed oceanographical results have yet to be published, but it is sufficient for 

 our purpose to note the main course of the currents and the bathymetrical features. 



The cold west drift current passes through Drake Strait and across the Southern 

 Atlantic. South Georgia lies athwart its course; a fact which has very important 

 bearings on the distribution of whale food and whales (see Hardy, Geogr.Jonrn., lxxii, 

 Sept. 1928). The Falkland Islands lie on the northern flank of this current, and between 

 them and the mainland of South America a warmer current flows southwards. 



These two currents seem to have but little influence on the pelagic Amphipods. The 

 three most abundant pelagic species in the Discovery collection are found in both 

 currents (cf. chart, Fig. 1), though a fourth species, Cyllopus lucasii, appears to be con- 

 fined to the colder waters. 



Within the limits of the cold west drift current, the distribution of the pelagic Amphi- 

 pods around South Georgia is noteworthy, especially as it coincides in a striking manner 



aX 



• Parathemisto gaudichaudii 



d Vibilia antarctica 



o Cyllopus magellanicus 



o Cyllopus lucasii 



a Primno macropa 



Fig. 2. Chart showing the stations around South Georgia at which the five commonest pelagic 

 Amphipods were captured. (Cf. Hardy, Geogr. Journ., lxxii, Sept., 1928, figs. 4, 5.) 



with the distribution of Eiiphausia superba (cf. Hardy, loc. cit. Figs. 4 and 5) and is 

 evidently due to similar ecological factors. 



With the exception of two captures of Parathemisto gaudichandii by members of the 

 Marine Station, not a single pelagic Amphipod was captured on the south-west side of 

 South Georgia ; whereas on the north-east side several species were found, some of them 

 in great abundance (cf. chart, Fig. 2). 



It is true that the two vessels of the expedition did more collecting on the north-east 

 side (cf. Discovery Reports, 1, Station list, pi. ii), but the 'William Scoresby' ran a line 

 of stations (WS 40-52 and 63) on the south-west side with entirely negative results, so 

 far as Amphipods are concerned. 



The conclusion seems warranted that the causes which Hardy {loc. cit) suggested 

 are operative determining the distribution of Eiiphausia, are operative also in the case 

 of the pelagic Amphipods. The same contrast in the relative abundance of Amphipods 

 on the two sides of South Georgia is found also in the bottom fauna, though in a much 

 less noticeable degree. 



