82 DISCOVERY REPORTS 



505 and 635 m. At Sts. WS 377, 506, 507 A, 507B the tests are to some extent sandy, 

 spicules being employed only as framework for the chambers. At the remaining stations 

 spicules form almost the entire test, as figured in the South Georgia report (SG 100, 

 pi. ii, fig. 20). The finest specimen, with five chambers, was found at St. WS 511. 



142. Reophax longiscatiformis, Chapman. 



Reophax longiscatiformis, Chapman, 1914, FORS, p. 63, pi. iii, fig. 18. 

 Reophax longiscatiformis, Heron-Allen and Earland, 1922, TN, p. 95. 



Six stations: 170, 198; WS 203, 471, 474, 482. 



Only a single fragment at each station. Three chambers in the fragment from St. 

 WS 471 and two, including a long slender proloculus, in the specimen from St. 170. 

 There is great range in the depths, 100 m. at St. WS 482 and 4259 m. at St. WS 203. 



143. Reophax micaceus, sp.n. (Plate II, figs. 37-40). 



Fourteen stations: 169, 194; WS 199, 203, 471, 472, 496, 497, 506, 507B, 509, 510, 515, 552. 



Test minute, rigid and fragile, more or less transparent ; consisting of 2-6 chambers 

 rapidly increasing in length, the last sometimes produced into a long and tapering neck. 

 Sutures slightly depressed. Constructed of a single layer of mica flakes cemented to- 

 gether by their edges, and without any admixture of sand except at the aperture, which is 

 denser in colour and structure and appears to be strengthened by the use of fine sand. 

 The size of the mica flakes determines the shape of the chambers, which are round in 

 section when the flakes are minute, rather angular when large. Length variable, up to 

 0-7 mm. 



This highly selective little organism is rare or very rare everywhere. Six of the 

 stations are in the deep water of the Weddell and Scotia Seas, between 2514 and 4845 m. ; 

 the others are in the Bellingshausen Sea, 505-812 m. It was most frequent at Sts. 

 WS 471 and 472 in the Scotia Sea, where the best specimens were obtained. 



It is a matter of some interest that the test of R. micaceus does not collapse when dried, 

 but retains its shape, though very fragile. R. scottii, also using mica flakes only for con- 

 struction, invariably collapses on drying and is then very fragile, though in life and when 

 preserved in fluid the chambers are inflated, and the whole test flexible. The flakes used 

 by R. scottii are very uniform in size and smaller than in R. micaceus, which uses flakes 

 of varying sizes even in a single chamber. 



144. Reophax flexibilis, Schlumberger (F 86) (SG 102). 

 Two stations: 192; Port Lockroy. 



A single specimen from 800 m. at St. 192, and two from anchor mud at Port Lockroy. 

 They are all small but typical. The stations are not far apart in the Palmer Archipelago. 



145. Reophax nodulosus, Brady (F 84 a) (SG 103). 



Thirty-two stations: 170, 175, 177, 180, 181, 194, 196, 360, 373, 382, 383; WS 203, 386, 393, 400, 

 468, 471, 472, 475, 482, 488, 495, 498, 502, 505, 506, 507 A, 507B, 515, 517, 552, 553. 



Occurs in all the areas and at all depths from 50 to 5029 m. Perfect specimens of 

 large size were seldom found in the material as obtained, but a few ranging up to 8 mm. 

 in length which had been picked out from the material when dredged were received in 



