294 DISCOVERY REPORTS 



6-8° C. temperature. It is of Pacific origin, and some of it probably comes down the 

 western coast of South America and, being swept through the Drake Straits with the 

 Pacific water of the West Wind Drift, would naturally turn up by the Falklands as soon 

 as it passes Cape Horn, which, projecting southwards, to some extent dams back the 

 flow of water. The West Wind Drift proper passes well to the south of the Falklands, 

 through the deep channel separating the Falklands from South Georgia, and so into the 

 Atlantic Ocean. The Pacific water, diverted northwards, forms the Falkland Islands 

 Current, encircling the islands. 



Evidence of the general low temperature of the water for the latitude is afforded by : 

 (i) the types of Foraminifera dominant in the bottom deposits, 

 (2) the absence or paucity of other types usual in such latitude. 

 As an example of (i) we may quote Cassididina crassa, which is universally distributed 

 in our material and frequently forms a major portion of the organic remains. Although 

 of almost world-wide distribution, this species is definitely a "cold area" form, and is 

 found in similar abundance in the cold areas of other oceans. 



As an example of (2) we may quote the genus Spiroloculina, which is unrepresented in 

 our Falkland material, although one of the commonest shallow- water forms in warm and 

 temperate seas all over the world. In the northern hemisphere, under the influence of 

 the warm Atlantic current (Gulf Stream), the genus is abundantly represented by 

 several species at least as far north as the Shetland Islands, which are in about the same 

 latitude as the Orkney Group in the southern hemisphere. 



The area covered by the stations is very extensive, as they spread over the sea bottom 

 roughly between 48-54° S and 57-68° W, which is more than the entire area of the 

 North Sea from Texel to the Shetlands, and from the shores of Great Britain to the 

 Continent. Nevertheless, owing to the enormous extension of the Continental Shelf and 

 the uniformly low bottom temperature, there is no great variety in the samples, except as 

 regards the fauna of the stations on the Shelf, and the fauna of the few deeper water 

 stations outside the Continental Shelf, which are under more normal benthic conditions. 



From the samples it would appear that the thousands of square miles of sea bottom on 

 the Continental Shelf consist of comparatively barren wastes of gravel and sand, usually 

 brown in colour. The larger grains are generally rounded, sometimes highly polished, 

 notably so at stations WS 92, 95, 219, 221, indicating either that they have travelled a 

 great distance, or that they are kept in constant motion by currents and wave action. 



There is, as a rule, little mud^ present in any of the deposits from the area to the 

 south and the west of the islands, within a line from Eddystone Light to Cape Tres 

 Puntas. Its absence may perhaps be due to the action of the current which passes to the 

 west of the islands, for the percentage of mud increases to the north of the islands and in 

 their lee, as it were, and the sand grains are smaller and more angular. Broken shells, 

 often covered with sessile Foraminifera, form an important percentage of the total bulk at 

 some stations, indicating a variety and abundance of organic life which is elsewhere absent . 



1 Samples taken in the conical dredge, which has a canvas bag, probably lose a small proportion of the mud 

 present. 



