ASTRORHIZIDAE 53 



Genus Ophthalmidium, Zwingli and Kiibler, 1870 



43. Ophthalmidium inconstans, Brady (F 51). 

 One station: 363. 



A single excellent specimen was found in 329 m. 



44. Ophthalmidium margaritiferum, Heron-Allen and Earland (Plate I, figs. 8, 9). 

 Ophthalmidium margaritiferum, Heron-Allen and Earland, 1922, TN, p. 72, pi. i, figs. 9-12. 



One station: 177. 



A single specimen from St. 177 in the Bransfield Strait in 1080 m. The shell wall is 

 thick and the sutural lines inconspicuous. The proloculus does not extend in the form 

 of a boss as in the original types, but this appears to be due to the thickness of the wall, 

 as the specimen when examined in fluid proved to have a large proloculus, and other- 

 wise agreed structurally with the type, which was found in Terra Nova dredgings oflF the 

 north end of the North Island, New Zealand. Its occurrence in the Antarctic is 

 noteworthy. 



Family ASTRORHIZIDAE 

 Sub-family ASTRORHIZINAE 

 Genus Astrorhiza, Sandahl, 1857 



45. Astrorhiza limicola, Sandahl (SG 34). 

 Two stations: 170, 182. 



A single poor specimen at St. 170, and two large specimens at St. 182, constitute the 

 only records. None of them is very typical, fine mud only being used for construction, 

 without the usual admixture of large sand grains, etc. 



46. Astrorhiza crassatina, Brady (SG 35). 

 Seven stations: 362, 382; WS 471, 472, 474, 495, 517. 



Specimens are frequent at Sts. WS 495, 517, though usually fragmentary. At Sts. 

 WS 471, 472, 474 very large specimens were obtained and many fragments noted. All 

 the stations are in deep water in the Scotia and Bellingshausen Seas. 



47. Astrorhiza triangularis, Earland (SG 36). 

 Three stations: 181, 182, 204. 



Rare at Sts. 181, 182, which He in the Palmer Archipelago. Only a single large and 

 rough specimen from St. 204 in the Bransfield Straits. The specimens attain rather 

 larger dimensions than in South Georgia, some exceeding 0-2 mm. in diameter, and are 

 less neatly constructed, the incorporation of a few large sand grains often spoiling the 

 symmetry of the test. 



48. Astrorhiza polygona, sp.n. (Plate I, figs. 13, 14). 

 Two stations: 177, 196. 



Test polygonal in outline, compressed, thinner at the edges than in the centre; con- 

 sisting of a single large chamber enclosed by a thin wall of sand and mineral grains 

 neatly and firmly cemented together. At more or less irregular intervals, the marginal 



