96 DISCOVERY REPORTS 



terminal chamber; wall thin and smoothly finished, built of very minute mineral grains 

 and other particles, attached in a single layer to the chitinous membrane and with little 

 sign of interstitial cement; colour light grey, often silvery, very rarely tinged with 

 ferruginous cement. 



Megalospheric : length up to 0-4 mm., breadth up to o-i mm. 



Microspheric : length up to 0-5 mm., breadth up to o-i mm., thickness o-o6 mm. 



This very delicate and distinctive little species is widely distributed in the shallower 

 waters of South Georgia between depths of 130 and 318 m., and also in many Antarctic 

 gatherings. A few doubtful fragments and a single small specimen were seen in deeper 

 water at WS 343 in 2856 m. 



It is common at St. 144 and WS 32, frequent at St. 45, rare, or very rare, elsewhere, 

 though owing to its small size and fragility it may perhaps be more abundant than it 

 seems at some stations. It varies considerably in size and development, the dimensions 

 given above being the maxima for South Georgia. 



The species is apparently trimorphic, two very distinct megalospheric forms are to be 

 found. One (A i) is much shorter and has fewer chambers than the other, but the 

 initial spiral is large and neatly rounded. The other megalospheric form (A 2) has the 

 apex almost as acutely pointed as in the microspheric form, and is equally long. 



The microspheric form appears to be acutely pointed. When examined in fluid some 

 specimens are seen to possess a complete initial spiral coil or planispire, while others 

 have apparently only a single apical chamber, the outermost chambers of the spiral 

 being worn away. A similar feature in T. sogittula, Defrance, has been observed by 

 Lacroix (L. 1929, TS, pp. 1-12, figs, i-io) and confirmed by us (H.-A. and E. 1930, 

 FPD, p. 72). 



On this analogy, I propose to refer my specimens to Textularia rather than to 

 Spiroplectammina, in which the initial planispire is distinct in both forms. 



After the foregoing description of what appeared to be a new species had been written 

 and was awaiting the press, Dr E. Lacroix of Lyons published a paper on the Textu- 

 lariidae of the Mediterranean Continental Shelf. My attention was at once arrested by 

 one of his new species, Textularia elegam (L. 1932, TPCM, p. 8, figs. 4-6), as his 

 figure of the microspheric form was in general agreement with my specimens, except as 

 regards size, the Mediterranean specimens attaining little more than half the maximum 

 dimensions of those from South Georgia. 



I sent specimens from the material to Dr Lacroix, who has no doubt as to their 

 identity with his species. He has been so good as to supply me with a Mediterranean 

 specimen for comparison. 



Apart from the difference in size, there appears to be little doubt as to the identity of 

 the organisms; the formation and number of chambers are the same, although the 

 texture of the shell is somewhat different. The Mediterranean specimens have a more 

 compact arrangement of the mineral particles, ferruginous cement uniting the grains 

 being visible, when the specimen is examined as a transparent object under a high 

 power. In the South Georgian specimens, there is no visible cement and the minute 



