34o DISCOVERY REPORTS 



Station WS 505. 4. ii. 30. Lat. 70 10J' S. Long. 87 46' W. 1500 m. (Plate XXI.) 

 Terrigenous mud. A brown mud composed of flocculent matter which encloses mineral grains. 

 The grains grade downwards in size from a diameter of about o-i mm. ; they are fairly angular in 

 shape and consist chiefly of quartz with occasional fragments of green hornblende. There are few 

 recognizable organisms, only a few tests of Cristellaria and fragments of Globigerina being noted. 



Station WS 506. 7. ii. 30. Lat. 70° 31' S. Long. 81° 36' W. 584 m. (Plate XXI.) 

 Terrigenous mud. A brown unctuous mud with the same general characters as the preceding 

 sample. 



Station WS 507a. 8. ii. 30. Lat. 70 32J' S. Long. 8i° 42' W. 572 m. (Plate XXI.) 

 Terrigenous mud. This sample resembles those from Sts. WS 505 and WS 506. The bulk of the 

 mineral grains are less than o-oi mm. in diameter, but some larger grains (o-i mm.) are of quartz 

 and green hornblende. The flocculent material encloses diatoms (frustules of Coscinodiscus), but 

 they are not plentiful. 



Station WS 507b. 8. ii. 30. Lat. 70 34' S. Long. 8i° 55' W. 580 m. (Plate XXI.) 

 Terrigenous mud. This deposit is closely similar to the last in general constitution. The larger 



mineral grains (o- 1 mm. diameter) include quartz and green hornblende. Frustules of Coscinodiscus, 



enclosed in flocculent aggregates, still retain their cell contents. 



Station WS 508. 10. ii. 30. Lat. 69 04' S. Long. 77 40' W. 309 m. (Plate XXI.) 



Fine gravel. The sample consists of a few small rounded pebbles, about 5 mm. in diameter. 



Station WS 509. 11. ii. 30. Lat. 67 18' S. Long. 69 28' W. 445 m. (Plate XXI.) 

 Diatomaceous mud. The flocculent material in this sample is definitely diatomaceous. It contains 

 many frustules of Coscinodiscus, Cocconeis, Thalassiosira and Fragilaria which are rather small, but 

 also larger ones (including Triceratium) which retain their cell contents. The mineral grains, ranging 

 downwards in size from 0-2 mm. in diameter, include angular fragments of quartz and green horn- 

 blende. 



Station WS 510. 11. ii. 30. Lat. 67 11' S. Long. 69 46' W. 505 m. (Plate XXI.) 

 Diatomaceous mud. This is a green-grey mud in which flocculent diatomaceous material is 

 dominant, and many of the frustules still enclose greenish cell contents. The chief genera are 

 Coscinodiscus, Fragilaria, Thalassiosira and Cocconeis. The mineral constituent consists mainly of 

 subangular grains of quartz (up to o-i mm. diameter) with occasional prismatic grains of green 

 hornblende. 



Station WS 511. n. ii. 30. Lat. 67 04' S. Long. 70 04' W. 635 m. (Plate XXI.) 

 Diatomaceous mud. A greenish grey mud which is mainly flocculent diatom debris. Whole 

 frustules of Coscinodiscus (0-2 mm.), Thalassiosira, Fragilaria, Cocconeis and Corethron occur along 

 with sponge spicules. Mineral grains (quartz and green hornblende) are usually angular and very 

 small, but some reach a diameter of 0-05 mm. 



Station WS 512. 11. ii. 30. Lat. 66° 57' S. Long. 70 22' W. 652 m. (Plate XXI.) 

 Diatomaceous mud. Flocculent diatom debris makes up the bulk of this greenish grey mud, in 



which whole frustules of Coscinodiscus, Cocconeis, Fragilaria, Rhizosolenia and Thalassiosira are noted. 



There is a subordinate proportion of subangular mineral grains, mostly less than 0-05 mm. in 



diameter, among which quartz and green hornblende are recognized. 



Station WS 513. 11. ii. 30. Lat. 66° 49^ S. Long. 70 40J' W. 560. m. (Plate XXI.) 

 Diatomaceous mud. A greenish mud of the same type as the preceding sample. Frustules of 



Coscinodiscus, Thalassiosira, Cocconeis, Biddulphia, Fragilaria, Corethron and Rhizosolenia are noted. 



Quartz grains form the greater part of the mineral fraction, while green hornblende also is present. 



