68 DISCOVERY REPORTS 



same material extend from the inner edges of the test towards the interior, but do not 

 extend over the middle of the floor ; their purpose is apparently to strengthen the walls 

 of the test. 



Greatest diameter of a hemispherical specimen 3-5 mm.; of an irregular specimen 

 nearly 5-0 mm. Height up to 2-0 mm. 



This remarkable form was found only at St. WS 482 in the Bransfield Strait, where it 

 was not uncommon on stones brought up in the nets. It was probably very abundant 

 in this locality, which is just off the extreme north end of the Graham Land peninsula. 



I broke open several perfect specimens and found them all stuffed with the fine sand 

 and containing the separate protoplasmic bodies. These could be removed with a needle 

 point, and were similar to the bodies extracted from Pelosina fusiformis and other 

 Arenacea, apparently protoplasm in a chitinous bag. 



I think these separate bodies represent merely a reproductive stage of the organism, 

 as in several abraded specimens the cemented floor of the cavity is covered with masses 

 of dried protoplasm, extending into the flanged cavities of the outer wall. This is even 

 more apparent in a single detached hemispherical specimen which contains a proto- 

 plasmic body large enough to have filled the entire cavity during life. 



Webbinella farcta probably has a wide distribution in the Antarctic, and perhaps 

 elsewhere in cold water. There are several specimens from Terra Nova and Dis- 

 covery (1901-4) stations off the Antarctic continent in the Ross Sea, in the Heron-Allen 

 and Earland collection in the British Museum. Their nature was not detected at the 

 time, and they were listed in the Terra Nova report with the sessile specimens of 

 Crithionina pisiim and C. mamilla. They are even larger and more convex than the 

 specimens from the Bransfield Strait, but agree in specific features. 



In the same collection is a pebble which I dredged from a depth of 1275 m. in the 

 "Cold Area" of the Shetland-Faroe Channel. (F.C. ' Goldseeker ', 14 August, 1910, 

 Haul 221, St. xiv B, 61° 18' N, 2° 59' W.) It bears a number of sessile organisms which 

 appear to be allied to W. farcta, though perhaps specifically distinct. They are circular 

 in form, but the height is greater than the breadth, like a drum with a superimposed 

 hemisphere. Firmly constructed of fine sand and cement, and bristling with long and 

 fine sponge spicules. Laid open, they are found to have a central cavity packed with 

 fine sand, containing cavities similar to those in W. farcta. 



Genus Tholosina, Rhumbler, 1895 



94. Tholosina bulla (Brady) (F 65) (SG 67). 



Eighteen stations: 163, 164, 167, 171, 175, 177, 180-2, 186; WS 386, 387, 468, 474, 475, 483, 

 488, 494A. 



Except at St. 181 in the Palmer Archipelago, where good specimens are common, the 

 species is rare everywhere. There is, as usual, great variation in the size and nature of 

 the material used for construction, and detached specimens are of frequent occurrence. 



95. Tholosina laevis, Rhumbler (SG 67) (Plate II, fig. 10). 



Tholosina laevis, Rhumbler (nov. spec.) in Wiesner, 193 1, FDSE, p. 86, pi. vii, figs. 80-2. 



