112 DISCOVERY REPORTS 



South Sandwich Islands through the Bransfield Strait to the Palmer Archipelago. Never 

 common, it occurs with some frequency at Sts. 363 and 366 in the Sandwich group, and 

 at St. 181 in the Palmer Archipelago. At the remaining stations it is rare or very rare. 

 Depths range between 155 and 1080 m., but it is most frequent and attains the largest 

 size under 350 m. The colour is usually very light grey, almost white at St. 181, but 

 darker at Sts. 363 and 366 owing to the use of black volcanic sand in construction. 



Family TEXTULARIIDAE 



Sub-family SPIROPLECTAMMININAE 



Genus Spiroplectammina, Cushman, 1927 



221. Spiroplectammina biformis (Parker and Jones) (F 115) (SG 152). 



Sixteen stations: 167, 169, 187, 191, 192, 194, 195, 209; Port Lockroy; 62° 57' S, 60° 20' 30" W; 

 WS 395, 485, 486, 488, 494A, 516. 



Common in the anchor mud from Port Lockroy, and frequent at St. 169 in 244- 



344 m. More or less rare at the remaining stations, which range down to 261 1 m. 



222. Spiroplectammina typica, Lacroix. 



Spiroplectammina typica, Lacroix, 1932, TPCM, p. 6, text-figs. 2-3. 



Two stations: 360, 369. 



Single specimens from 1767 m. at St. 369 in the South Sandwich Islands, and St. 360 

 (3264 m.) in the Scotia Sea agree with Lacroix's figures and description. The species is 

 distinguished by its very thin initial spiral, the subsequent chambers increasing rapidly 

 in thickness ; also by its roughly constructed test, sand grains of varying sizes being 

 utilized. 



223. Spiroplectammina subcylindrica, sp.n. (Plate IV, figs. 33-35)- 

 Nine stations: 360, 382, 386; WS 400, 469, 471, 472, 502, 503. 



Test minute, sub-cylindrical, rounded at the initial extremity, obtusely pointed at the 

 oral end. No perceptible decrease of thickness at the initial extremity. Sides parallel, 

 sutures indistinct and nearly flush. Aperture small, normal. The surface is uniformly 

 rather rough owing to the size of the sand grains and the small quantity of cement em- 

 ployed in construction. Colour yellowish brown. 



Owing to the rough surface and flush sutures very little structure can be made out in 

 opaque specimens. Mounted in balsam the test is seen to be composed of an initial 

 closely coiled spiral of 6-8 chambers, followed by 2-4 pairs of textularian chambers. 

 The walls are rather thick for the size of the organism. 



Average length 0-25 mm. ; breadth 0-13 mm. ; thickness o-i mm. 



This is a very distinctive little form, and appears to be confined to deep water in the 

 Scotia and BeUingshausen Seas, the records ranging from 3264 to 4773 m. It is common 

 at St. WS 503, but the specimens are undersized; frequent at WS 471, 472; rare at the 

 remaining stations. 



224. Spiroplectammina filiformis, sp.n. (Plate IV, figs. 30-32). 

 Seven stations: 360, 362, 383 ; WS 203, 471, 472, 474. 



Test minute, almost circular in section ; initial spiral small but prominent, containing 



