348 DISCOVERY REPORTS 



fibula is occasionally seen. The mineral grains include quartz (up to 0-15 mm. diameter) and green 

 hornblende (0-05 mm. diameter). 



Station WS 697. 21. vii. 31. Lat. 05 55' 30" S. Long. 8i° 09' W. 75 m. (Plate XXII.) 

 Diatomaceous mud. A dark sandy mud in which mineral grains form a greater bulk than flocculent 

 matter. The mineral grains are mostly angular fragments of quartz, brown and green hornblende, 

 volcanic glass, with a maximum diameter of about 0-2 mm., but flakes of white mica are sometimes 

 0-5 mm. across; a small crystal of tourmaline (0-05 mm.) is also noted. The flocculent material is 

 present in considerable quantity, and whole frustules of Coscinodiscus, Biddulphia, Actinoptychus and 

 Navicula are plentiful. A few tests of the silicoflagellate Dictyocha fibula are noted. 



Station WS 700. 21. vii. 31. Lat. 05 52' S. Long. 81° 15' 30" W. 310 m. (Plate XXII.) 

 Diatomaceous mud. The sample consists mainly of green, granular, flocculent material which 

 contains entire frustules of Coscinodiscus, Actinoptychus, Achnanthes and Navicula, the first-named 

 being particularly large and abundant. The mineral fraction contains small angular grains of quartz, 

 volcanic glass and brown hornblende, which are mostly less than 0-05 mm. in diameter. 



Station WS 701. 21. vii. 31. Lat. 05 48' S. Long. 8i° 22' 30" W. 1083 m. (Plate XXII.) 

 Diatomaceous mud. This consists largely of flocculent material of the usual type, in which frus- 

 tules of Coscinodiscus are prominent; the silicoflagellate Dictyocha fibula and textularian Foraminifera 

 are occasionally seen. Mineral grains, usually below 0-05 mm. in diameter, are mainly of quartz and 

 volcanic glass. 



Station WS 702. 21. vii. 31. Lat. 05 38' S. Long. 8i° 40' W. 3102 m. (Plate XXII.) 

 Diatomaceous mud. Large frustules of Coscinodiscus are plentiful together with smaller tests of 

 Actinoptychus and Synedra in the flocculent material which is of the usual type. In the small amount 

 of mineral grains, quartz, volcanic glass and green hornblende occur in fragments which are usually 

 less than 0-05 mm. in diameter. 



Station WS 703. 22. vii. 31. Lat. 05 34' S. Long. 8i° 11' 30" W. 4742 m. (Plate XXII.) 

 Diatomaceous mud. The deposit is composed largely of granular flocculent material in which 

 large frustules of Coscinodiscus are plentifully distributed. Apart from this, recognizable diatoms are 

 not numerous but the occurrence of Aster omphalus is noted. Angular quartz grains (0-05 mm.) are 

 sparsely scattered through the flocculent mass. 



Station WS 705. 23. vii. 31. Lat. 05° 35' 30" S. Long. 83 41' 45" W. 4026 m. (Plate XXII.) 

 Diatomaceous mud. An unctuous brown mud with a small proportion of tiny mineral grains (less 

 than o-o 1 mm. diameter), chiefly angular particles of quartz and volcanic glass. The flocculent 

 aggregates enclose abundant frustules of Coscinodiscus together with some of Synedra and Thalassio- 

 thrix, also fragments of Radiolaria. 



Station WS 708. 25. vii. 31. Lat. 04 18' S. Long. 82 05' W. 4314 m. (Plate XXII). 



Diatomaceous mud. Composed of green flocculent material of the usual type with a very small 

 amount of mineral grains, mostly less than o-oi mm. in diameter. Coscinodiscus is the most prominent 

 of the diatoms and there are numerous fragments of Radiolaria. 



Station WS 711. 27. vii. 31. Lat. 04 19' 30" S. Long. 8i° 27' W. 1885 m. (Plate XXII.) 

 Terrigenous mud. This sample is formed largely of flocculent material which is responsible for 

 the green colour of the deposit. A few diatoms (Coscinodiscus) are present, usually retaining their 

 cell contents. The flocculent matter is more abundant than usual in a typical terrigenous deposit, but 

 there is a general paucity of recognizable organisms. The mineral grains are mainly subangular in 

 shape and include quartz (up to 0-25 mm.) and green hornblende. 



Station WS 717. 31. vii. 31. Lat. 02° 02' S. Long. 81 ° 18' 30" W. 1649 m. (Plate XXII.) 

 Diatomaceous mud. This sample has a fair proportion of sandy material, the grains of which are 

 mainly about o-i mm. in diameter. The quartz grains reach a maximum of 0-25 mm., while fragments 



