30 DISCOVERY REPORTS 



with the physical characters of the deposits. Four species of Globigerina only are men- 

 tioned (G. dubia, rubra, bulloides, sacadifera), the last of which is almost certainly mis- 

 identified. 



MATERIAL EXAMINED 



Bottom samples were received from about ninety stations, over fifty of them being 

 fairly evenly distributed in the shallower coastal waters, while the others consist of lines 

 of soundings run out in various directions into the very deep water surrounding the island. 

 The vast majority of the samples consisted of sounding materials only, the quantity 

 rarely exceeding 25 cc, and in most cases much less. Almost without exception these 

 soundings consisted of tenacious mud of shades varying from grey and blue to almost 

 black. They were treated by washing on a silk sieve of 200 meshes per linear inch, and the 

 residues were generally very small, seldom more than a few cc. The muds, which were 

 preserved in spirit, were frequently refractory, in which case the method followed 

 was to dry thoroughly after a preliminary washing, break down the dried residue with 

 boiling water and wash again. In a few instances only it was found necessary to use soda to 

 break down the deposit. 



The chief difficulty in the cleaning process lay in the abundance of Diatoms. Apart 

 from the smaller forms which passed readily through the sieve, larger species, notably 

 Fragilaria antarctica, Cocconeis imperatrix and Cestodisciis gemmifer, were often present 

 in such numbers as to form a felt in the sieve. It was not possible to separate them from 

 the smaller and lighter species of Foraminifera, such as Virgulina, which were often 

 equally abundant, and their presence added to the difficulty and monotony of the ex- 

 amination of the residues. Another Diatom, presumably Nitzschia sp., which was 

 equally abundant and the principal cause of the felting in the sieves, could be more or 

 less eliminated after cleaning, as it separated from the dried material when shaken in a 

 tube, forming masses like cotton-wool. 



No great variety of species can ever be expected in shallow-water soundings. As the 

 Foraminifera exist mainly in the surface layer, the area sampled by the sounding tube is 

 not large enough to ensure much of a catch. The large arenaceous species which, from 

 other sources, are known to be present, are not in sufficient numbers to ensure capture, 

 and when taken were generally fragmentary. 



The examination of these shallow-water soundings therefore proved a long and 

 monotonous task. Station after station yielded approximately 20-30 species, mostly 

 identical. Now and then the occurrence of a species not previously observed gave some 

 encouragement to proceed with the work. 



The typical species inhabiting the coastal waters occur in nearly every sample, 

 material from each station as a rule furnishing one or two other species of less constant 

 distribution. Broadly speaking, the typical species are as follows (those marked * may 

 be regarded as being peculiarly characteristic and constant) : 



Ammodiscus incertus *Cassidulina suhglobosa 



Cassidulina crassa *Ehretibergina crassa 



*Cassididina parkeriana *Glohigeriiia dutertrei 



