62 DISCOVERY REPORTS 



The species differs from .S'. confusa in its spreading habit, the colony consisting of a 

 single layer of chambers, instead of an associated mass as in S. confusa, which also does 

 not use ferruginous cement. It differs from S. depressa, which has a similar spreading 

 habit of growth, in its firmly cemented wall constructed of large sand grains with 

 ferruginous cement. S. depressa uses only the finest sand without ferruginous cement, 

 the individual chambers are larger and are never so closely packed together. . 



Associations of a few individuals are less closely compacted than larger colonies, thus 

 preserving to some extent the shape of the individual chambers. This is evidently very 

 variable, as in S. depressa. Two young specimens from St. 175 approach the cylindrical 

 in form, others at 170 and elsewhere flat and cake-shaped, or entirely irregular. A colony 

 of four individuals at St. 182 is nearly circular and quadripartite, very like the figure of 

 S. depressa in the South Georgia report (pi. v, fig. 20), but the separate chambers are not 

 deeply separated as in that figure. 



Genus Psammosphaera, F. E. Schulze, 1875 



79, Psammosphaera fusca, Schulze (F 60) (SG 56). 



Seventy stations: 161, 164, 169, 170, 175, 177, 180-2, 186, 187, lyi, 196-8, 203, 204, 206, 360, 

 363, 366, 373, 377, 383-6 ; 62° 57' S, 60° 20' 30" W ; WS 199, 201 , 203-5, 377, 382, 385-7, 389, 394, 400, 

 403, 468, 469, 471, 472, 474, 481, 482, 484, 485, 488, 493, 494A, 495, 502, 503, 505, 506, 507 A, 

 507". 509. 512, 514-7, 552, 553, 555. 



Generally distributed in all areas and at all depths, often very common. As usual 

 there is great variety in form, due to the greater or less degree of selective power shown. 

 The most widely distributed form in all the areas is somewhat roughly constructed, 

 very large sand grains being used, and the interstices neatly filled in with smaller grains, 

 the result being an irregularly shaped test. This form is common at Sts. WS 495, 552 

 and frequent at Sts. 203, 373, 384, WS 203, 382, 389, 403, 472, 488, 506, 507 A, 555. 

 Very large specimens at Sts. 373, WS 495. It is similar to those figured in the Falklands 

 report, pi. viii, fig. 3, and apparently the same as Psammosphaera irregularis, Wiesner 

 (W. 193 1, FDSE, p. 80, pi. iv, fig. 34), which I have not considered worth separating 

 even as a variety. 



Second in point of numbers and width of distribution is the normal spherical type, 

 in which sand grains of approximately equal size are strongly cemented together with 

 ferruginous cement, giving a brown colour to the test. This form is common at Sts. 170, 

 383, 385, WS 469, 482, and frequent at St. 175. As a rule one form or the other pre- 

 dominates at a station, but at Sts. 180, WS 471, 517 they occur together and in equal 

 abundance. The peculiar variety which was figured in the Falklands report (pi. viii, 

 figs. I, 2), utilizing only a few very large sand grains, is very rare, but was observed at 

 Sts. WS 494 A and 516. Sessile specimens occurred at many stations and were notice- 

 ably common at Sts. 180, WS 201, 482. Associated or double shells were observed at 

 Sts. 383, WS 469, 474 and 552. 



80. Psammosphaera fusca var. testacea Flint. 



Psammosphaera fusca var. tisiacca, I'liiii, 1899, RFA, p. 268, pi. viii, fig. 2. 



