ASTRORHIZIDAE 6i 



Sub-family SACCAMMININAE 

 Genus Sorosphaera, Brady, 1879 



76. Sorosphaera confusa, Brady (SG 54) (Plate I, fig. 25). 

 One station: 170. 



A single specimen, small but quite typical, from 342 m. at Clarence Island. 



77. Sorosphaera depressa, Heron-Allen and Earland (SG 55) (Plate I, figs. 19-21). 

 Twenty-two stations: 170, 175, 177, 180, 181, 182, 201, 204, 206, 377; WS 201, 382, 387, 393, 



403. 475. 482, 484. 485. 488, 494A, 5H- 



Generally distributed, except in the Bellingshausen Sea, which furnishes only one 

 record — at WS 514, where it is very rare. St. 175 in the Bransfield Strait is the only 

 locality where the species is at all frequent, but a large number of specimens were col- 

 lected altogether. In the majority of cases these were single-chambered free individuals, 

 and the shape varies more than the South Georgia illustrations suggest, from very flat 

 cake-like to roughly spherical tests. The latter are often attached to a single sand grain, 

 which apparently gives them no alternative but to grow upwards and outwards in an 

 inflated form. Both sessile and free individuals often occur at the same station, as at 

 Sts. 170, 175, 181, WS 387, 482, 484. The best sessile colonies were found at Sts. 

 WS 387, 482. Moderately shallow water seems most favoured, but specimens were 

 found at all depths down to 4134 ni. It is probable that the species is more widely 

 distributed than the records suggest, as stones suitable for its growth were not common 

 in the soundings received. 



Cushman in his recently published paper on Arctic Foraminifera (C. 1933, NAF, 

 pp. I, 2) suggests that this species probably belongs to the genus Urnula, Wiesner, 1931, 

 and should be known as Urnula depressa (Heron-Allen and Earland). But our species 

 has not a single point in common with the minute organism ascribed to Urnula. It has 

 no aperture, and no chitinous base, and the "accidental openings" in our figure 

 (pi. V, fig. 21), to which he refers as similar to those in his figure of Urnula arctica, are 

 purely fortuitous, the drawing having been made from a damaged specimen. 



78. Sorosphaera socialis, sp.n. (Plate I, figs. 22-24, ^"^^ P^^te II, fig. i). 

 Four stations : 170, 175, 181, 182. 



Test large, free or sessile, composed of a variable number of individual chambers 

 without external apertures associated in a colony, composed of a single layer of chambers, 

 but without apparent means of communication between the chambers. Walls thin but 

 very firm, built of rather coarse sand with abundant ferruginous cement, smoother ex- 

 ternally than internally. Shape of the individual chambers variable, but generally 

 speaking rounded, modified by contact and becoming somewhat hexagonal. Colour 

 dark brown. All the specimens found are free, but several show signs of having been 

 sessile before detachment. 



Size of colonies up to 3-0 mm. in diameter, individual chambers between 0-2 and 

 0-8 mm. Very rare at all the stations, the best being Sts. 170, 175. The largest specimen 

 was found at St. 181. The depths range from 200 to 500 m. 



