,oo DISCOVERY REPORTS 



hauls taken east-about from South Africa to South America and those from about half 

 the net hauls made in the Falkland sector in each of the two seasons have been examined. 

 Some of the larvae described were sought for and found in the hauls of a finer and smaller 

 net, 70 cm. in diameter, fished vertically at the same stations, or in other collections; 

 adult E. crystallorophias and E. hanseni are described from material collected at another 

 time.^ 



30 

 I 



40° 

 I 

 SUB-TROPICAL 

 CONVERGENCE 



50° 



ANTARCTIC 

 CONVERGENCE 



SOUTH 



IOOOm- 



EOODm 



3000 M 



4000m 



SUB-ANTARCTIC ZONE 

 < . 



SUB-TROPICAL WATER 



ANTARCTIC 

 INTERMEDIATE CURRENT 



^MIXED- 

 WATER 

 REGION 



ANTARCTIC 



SURFACE CURRENT 



WARM 

 DEEP CURRENT 



/ 



ANTARCTIC 

 BOTTOM CURRENT 



/ 



Fig. 5. Vertical diagrammatic section showing the vertical and meridional ranges and movements of the 

 water masses of the subtropical, sub-Antarctic and Antarctic Zones. 



THE SURFACE WATERS OF THE SOUTHERN OCEANS^ 



The surface of the southern oceans is divided from south to north into three well- 

 defined zones of different origins : the Antarctic, sub-Antarctic and subtropical Zones 

 (Fig. 4). Where the waters of two zones meet the heavier sinks below the surface and 

 sets up a hydrological boundary or convergence. The vertical and meridional movements 

 of the waters of these zones and of the deep currents below them are shown diagram- 

 matically in Fig. 5. 



1 The positions of all the stations are shown in Figs. 1-3. In charts showing the distribution of individual 

 species the only stations included are those from which the Euphausians where examined. 



2 This section was written with the help of Mr G. E. R. Deacon, hydrologist, who will shortly be 

 publishing in the Discovery Reports an account of the hydrology of the Southern Oceans. 



