ASTRORHIZIDAE S9 



end. It is probably an instance of the fusion of two individuals which have constructed 

 a joint test, but there is no sign of a junction in the test. 



69. Pilulina arenacea, sp.n. (Plate I, figs. 15-17). 

 Two stations: 366; WS 468. 



Test monothalamous, spherical or oval in shape; with a thin wall composed almost 

 entirely of fine sand grains and mud, with an occasional sponge spicule embedded, 

 though in contrast with the other species of the genus, P. jeffreysii. Carpenter, and P. 

 ovata, Cushman, spicules are conspicuous by their absence. Aperture a large slit with 

 more or less puckered edges, conspicuous and projecting. Colour varying between 

 nearly white to dark grey according to the minerals employed for construction. Surface 

 smooth but not highly finished, the larger sand grains projecting slightly above the 

 general level. Size variable, up to rather more than 2-0 mm. diameter in the largest 

 spherical specimen. Oval specimens are about 1-5 mm. in length, 1-2 mm. in breadth. 



The description is based upon a few specimens found at St. 366, off Cook Island in 

 the South Sandwich group, depth 155-322 m. The material was a black volcanic sand 

 and the tests have the dark grey colour characteristic of South Sandwich Arenacea. 



At St. WS 468 which is in the deep water of the Scotia Sea, 4344 m., a small specimen 

 was found which is probably a young individual of this species. It is almost spherical, 

 white with a dull rough surface, composed of very fine sand and mud with no visible 

 cement. The aperture is a broad slit, perhaps eroded, as it does not project above the 

 surface. Diameter 0-9 mm. 



Genus Bathysiphon, M. Sars, 1872 



70. Bathysiphon filiformis, G. O. Sars. 



Bathysiphon filiformis, G. O. Sars, 1871-2, HF, p. 251. 



Bathysiphon filiformis, Brady, 1884, FC, p. 248, pi. xxvi, figs. 15-20. 



Bathysiphon filiformis, de Folin, 1887, B, p. 279, pi. vi, fig. 4 «-e. 



Bathysiphon filiformis, Pearcey, 1914, SNA, p. 999. 



Bathysiphon filiformis, Cushman, 1918, etc., FAO, 1918, p. 27, pi. xi, figs. 4-5. 



Five stations: 362, 384; WS 469, 552, 555. 



Represented by rare fragments only, mostly of medium-sized individuals, but at 

 Sts. 362 and WS 555 fragments of both medium and very large specimens were found. 

 Except at Sts. 362 and 384, where fragments of the normally smooth type were found, 

 all the specimens are constructed of mineral grains sufficiently large to be observable in 

 the outer covering. Pearcey has already drawn attention to a similar abnormal method 

 of construction in the ' Scotia ' specimens from the Weddell Sea, and accounted for it by 

 their environment of glacial mud. All the records are from ver>' deep water, 3370- 

 4845 m. 



71. Bathysiphon capillaris, de Folin (SG 51). 



Twenty stations: 171, 177, 180-2, 196, 362, 366; WS 384, 393, 395, 403. 472, 479, 482, 486, 515, 

 517. 552, 553- 



Generally distributed, frequent at Sts. 171, 181, 366, WS 479, 482, rare or very rare 



8-2 



