SOUTH GEORGIA 9 



bergina crassa (SG 193), recorded from fifty stations in South Georgia and often very 

 common, is represented in the rest of the Antarctic material by a single specimen, which 

 I am inclined to regard as a " stray". Its place in the southern areas is taken by a com- 

 paratively small, but structurally closely allied form, Ehreubergina parva (No. 298), 

 which was not found in South Georgia. It is difiicult to resist the theory that E. parva 

 was the original Antarctic species which, in the isolation and richer feeding ground of 

 South Georgia, has developed into the large and stoutly constructed E. crassa. Again 

 Ammobaciilites bargmauni (SG 118), the largest species of its genus, and A. rostratus 

 (SG 1 19) are both typical South Georgia species of not infrequent occurrence. Neither 

 of them has been found in the southern material. Armorella sphaerica (SG 71 and No. 

 98), recorded from twelve stations in South Georgia and at times common, occurs at 

 seven stations among the island groups, but except at one station is always rare. 

 Hippocrepmella hinidinea (SG 82 and No. 114), recorded at thirteen stations and 

 abundant in Cumberland Bay, is extremely rare at the three stations from which it is 

 recorded in the Antarctic. Gordiospira fragilis (SG 33 and No. 41), recorded from six 

 stations and common at several of them, was found at one station only, ofl^ the South 

 Orkney Islands. Other instances could be given, but these are sufficient to show that 

 South Georgia has an Antarctic fauna of a peculiar and isolated description. 



A comparison of the South Georgia list with the present report shows that its 

 345 species and varieties include more than sixty which were not recorded in the 

 southern areas. But too much stress should not be laid upon these deficiencies, as 

 many of them are small shallow- water forms favouring a muddy habitat, and therefore 

 less likely to occur in the coarser and generally deeper material from the Antarctic. 

 Conversely it is well to mention one of these smaller species which has a very different 

 distribution in the two areas. Trochammina bradyi (F iii, SG 137 and No. 196), a 

 small but distinctive species, was recorded from sixty-five stations in the Antarctic, and 

 is often one of the commonest forms, especially in the Bransfield Strait area. But in 

 South Georgia it was recorded as " very rare " at only three stations, all on the north or 

 " Lee " side of the island, as the currents run. So it is not easy to avoid thinking that the 

 species is of comparatively recent introduction to South Georgia, and has not yet 

 established itself there. A single specimen was found in the Falklands area. The known 

 distribution of T. bradyi is peculiar: it is not uncommon in British dredgings and 

 generally on the eastern shores of the North Atlantic, but Cushman says that it is not 

 found on its western shores. The 'Terra Nova' recorded it in the Ross Sea, and Side- 

 bottom from deep water on the east coast of Australia. The Discovery specimens may 

 have been derived from either of these southern centres of distribution, as Wiesner does 

 not record it ofi^ Kaiser Wilhelm's Land, and I do not remember any other published 

 records. 



PREVIOUS WORK IN THE AREA 



Many expeditions have traversed the regions under survey but, so far as I am aware, 

 only two reports on Foraminifera collected by them have been published. 



