LITUOLIDAE 99 



form between the simple tube of Ammodisciis and the fully septate Trochammininae. 

 Its nearest ally appears to be Litiiotiiba, Rhumbler, 1895, based on Trochammina 

 liiuiformis, Brady. 



Genus Trochammina, Parker and Jones, i860 



188. Trochammina squamata, Jones and Parker (F 104) (SG 131). 



Twenty-seven stations: 177, 195, 360, 362, 373, 382-5 ; WS 199, 203, 204, 400, 403, 468, 469, 471, 

 472, 474, 476, 495, 502, 503, 516, 517, 552, 555. 



Almost confined to the deepest water stations, eighteen of the records being from 

 over 3000 m., and only three under 2000 m. Specimens are usually rather small but 

 were very large and typical at Sts. WS 203, 469, 472 and 517, where they were frequent, 

 and at St. WS 468, where the species was rare. A small sessile individual was found at 

 St. WS 199 where free small specimens were frequent. Small specimens were common 

 at St. WS 471. 



189. Trochammina rotaliformis, J. Wright, MS. (F 105) (SG 132). 



Twenty-one stations: 170, 175, 180, 181, 187, 191, 195-7, 200, 204, 206, 363, 366; Port Lockroy; 

 WS 382, 389, 476, 482, 485, 494A. 



Common in the anchor mud from Port Lockroy, and frequent at Sts. 175, 180, 206, 



363, WS 482 and 485 ; rare or very rare elsewhere. Nearly all the records are in shallow 



water, but there are a few deep records extending down to 1974 m. at St. 197. Nearly 



all the specimens are very dark in colour, resembling T. ochracea, from which in fact 



they are only separable by the highly convex dorsal surface. 



190. Trochammina ochracea (Williamson) (F 107) (SG 133). 



Fifty stations: 169-71, 175, 177, 180, 181, 185-7, 190-2, 194, 196, 199, 200-4, 206, 209, 363; 

 62° 57' S, 60° 20' 30" W; 64° 56' S, 64° 43' W; Port Lockroy; WS 386, 387, 391, 393, 395, 468, 

 479, 480, 481-7, 489, 493, 494A, 494B, 496, 497, 509, 515. 



Very widely distributed, and found at all depths down to 4344 m. at St. WS 468 in the 

 Scotia Sea, where two specimens were obtained. But the majority of the records are 

 from less than 1000 m., and the stations at which the species is common or frequent, 

 viz. Sts. 175, 180, 190, 200, 206; WS 482, 485 and Port Lockroy, are all under that 

 depth, and mostly under 200 m. At the remaining stations it is rare or very rare, often 

 represented by single specimens. 



191. Trochammina inflata (Montagu) (F 108) (SG 134) (Plate III, figs. 41-43). 

 Twenty-three stations: i6i, 170, 177, i8c^2, 196, 360, 362; WS 395, 471, 474, 488, 494A, 498, 



502, 509, 510, 513, 5iS-i7>555- 



Nearly always rare, only single specimens at most stations. The most typical and 

 largest specimens were found at Sts. WS 395, 488 and 513. The records extend to 

 4224 m. at St. WS 502, but the majority are under 1000 m. 



The specimens are smaller than the British type, and there is a tendency to develop 

 height in the spire, the test becoming highly convex on the dorsal side with inflated 

 chambers. This is most marked at Sts. 181, 196, 360, 362, WS 494 A and 509. 



13-2 



