332 DISCOVERY REPORTS 



tests of diatoms while some whole frustules of Coscinodiscus and Fragilaria are present, along with 

 sponge spicules. 



This, like the preceding three samples, is lighter in colour than most samples of diatomaceous mud, 

 and apart from the considerable proportion of mineral grains, has almost the appearance of diatom 

 ooze. 



Station WS 255. 22-23. viii - 2§ - Lat - 53° 2 3' s - Lon g- 44° I0 ' w - 3 00 3 m. (Plate XVII.) 

 Diatom ooze. The bulk of this light-coloured mud is composed of diatom frustules. In the 

 considerable variety of forms, the genera Coscinodiscus, Thalassiosira, Cocconeis, Fragilaria, Thalassio- 

 thrix and Rhizosolenia are noted. Sponge spicules and Radiolaria are represented, the latter by 

 occasional nasselarian forms. There is a small proportion of quartz grains, mostly below 0-05 mm. 

 in diameter. 



Station WS 314. i.xii. 28. Lat. 53 36' S. Long. 41 05' W. 137 m. (Plate XVII.) 

 Sand. The most interesting feature of this extremely small sample of sand is the large proportion 

 of colourless flakes up to 0-2 mm. in diameter, some of which show a sharp, unworn, hexagonal 

 outline; some show a radial texture and are evidently zeolitic aggregates. A few diatoms are present, 

 among which Coscinodiscus and Fragilaria are noted. There is some evidence of ferruginous 

 cementation. 



Station WS 317. 4. xii. 28. Lat. 52° 41' S. Long. 49 39' 30" W. 3369 m. (Plate XVII.) 

 Gravel. The sample consists of a few small black pebbles. The label states, "It is probable that 

 the finer constituents of the sample were washed out, and the coarse only retained ". 



Station WS 319. 5. xii. 28. Lat. 52° 01' S. Long. 54 52' W. 1602 m. 



Gravel and coarse sand. A small sample concerning which the Station List notes "finer material 

 from bottom sample washed out". It contains a few tests of Globigerina, some small pebbles, 

 and a little coarse sand. The latter includes some dark opaque grains (up to 1 mm. diameter), 

 rounded and lobate in shape ; when crushed they show the optical characters of glauconite. As the 

 sample is incomplete the station has not been entered on Plate XVII. 



Station WS 374. 6-7. ii. 29. Lat. 55 09' S. Long. 40 00' W. 3226 m. (Plate XVII.) 

 Diatom ooze. A brownish deposit with some admixture of mineral grains, but a fairly typical 

 diatom ooze. The diatoms include species of Coscinodiscus, Fragilaria, Thalassiothrix and Rhizo- 

 solenia. A few tests of Globigerina and Radiolaria are present. 



Station WS 377. 9. ii. 29. Lat. 58 34' S. Long. 44 47' W. 2552 m. (Plate XVII.) 

 Diatom ooze. The mineral constituent in this brown mud is very small, consisting of angular 

 grains which are usually much smaller in diameter than the maximum of o-i mm. Diatoms make up 

 the bulk of the deposit, occurring in some variety as whole frustules and also as broken material in all 

 stages of disintegration. Coscinodiscus, Fragilaria, Rhizosolenia and Thalassiothrix are most abundant, 

 while Thalassiosira and Asteromphalus occur more rarely. Occasional fragments of Radiolaria and 

 Foraminifera are noted. 



Station WS 381. 14. ii. 29. Lat. 6i° 26' S. Long. 56 19' W. 425 m. (Plate XVII.) 

 Coarse sand. This small sample contains mineral grains up to 1 mm. in diameter, all fairly angular 

 in shape. Quartz, green hornblende and volcanic glass are represented, as well as smaller grains of 

 phillipsite which often occurs as cross-twin or flat, hexagonal crystals. The sample is almost free of 

 organic debris, only a few diatoms being noted. 



Station WS 382. 15. ii. 29. Lat. 62 15' 35" S. Long. 58 18' 30" W. 425 m. (Plate XX.) 

 Terrigenous mud. The coarse fraction consists almost entirely of mineral grains, the size of 

 which ranges downwards from about 0-2 mm. in diameter. The finer material comprises exceedingly 

 small mineral grains together with some indefinite flocculent aggregates. Recognizable organic 

 remains are scanty, but include diatoms (Coscinodiscus and Fragilaria) and sponge spicules. 



