SEA-FLOOR DEPOSITS. PART I 331 



Station WS 108. 25. iv. 27. Lat. 48 30' 45" S. Long. 63 33' 45" W. 118 m. (Plate XVIII.) 

 Sand. A clean, evenly graded quartz sand with plentiful hypersthene and some opaque grains ; the 



mineral fragments have an average diameter of about 0-3 mm., and are generally rounded in shape. 



There is a small amount of flocculent matter, but apparently no shelly material. 



Station WS 109. 26. iv. 27. Lat. 50 18' 48" S. Long. 58 28' 30" W. 145 m. (Plate XVIII.) 

 Sand. The sample consists of clean rounded quartz grains with some sponge spicules and a little 

 muddy material. The latter consists of extremely small flocculent particles, the aggregates of which 

 apparently give the dark colour to the sand. Many of the mineral grains have a diameter between 

 0-25 and 0-5 mm. Besides quartz grains, rounded crystals of hypersthene, up to 0-5 mm. in length, 

 are occasionally seen. 



Station WS 128-129. 10-u.vi.27. Between 40° 19' S, io°04' Wand 40 10' 30" S, 9° 40' 45" W. 

 Between 2000 and 3000 m. (Plate XVII.) 



Globigerina ooze. This is a typical Globigerina ooze with the usual preponderance of Globigerina 

 shells up to 0-5 mm. across. Some rotalines are also present. There is a small proportion of angular 

 sand grains, some of which are 0-2 mm. in diameter. In the finer fraction, coccoliths are extremely 

 abundant, but rhabdoliths are less plentiful. 



Station WS 201. 22. iv. 28. Lat. 59 57' S. Long. 50 12' W. 4134 m. (Plate XVII.) 

 Diatomaceous mud. A small proportion of large, dark-coloured mineral grains includes volcanic 

 glass (up to 0-5 mm. diameter), while quartz (0-2 mm.), green hornblende and a few small prismatic 

 grains of glaucophane are noted. The larger grains are mostly well rounded. The fine-grained material 

 which makes up the bulk of the deposit consists partly of angular mineral grains, but largely of 

 diatom debris among which whole frustules of Coscinodiscus, Cocconeis and Fragilaria are abundantly 

 represented. The mud is dark brown when wet but becomes much lighter in colour on drying, and in 

 the almost colourless quality of the fine-grained material the deposit approaches a diatom ooze. 



Station WS 202. 23. iv. 28. Lat. 6o° 23' S. Long. 52 52' W. 3987 m. (Plate XVII.) 

 Diatomaceous mud. The coarser fraction consists largely of mineral grains up to 0-3 mm. in 

 diameter; it includes angular fragments of quartz, green hornblende and brown volcanic glass. The 

 finer material is an admixture of tiny mineral grains and diatom debris among which large frustules of 

 Coscinodiscus up to 0-25 mm. in diameter are conspicuous. Triceratium , Biddu/p/iia and other centric 

 forms, as well as Rhizosolenia and Fragilaria, are also present. Like the sample from St. WS 201, 

 this sample approaches a diatom ooze in its light colour and in the quality of its fine-grained material. 



Station WS 203. 25. iv. 28. Lat. 57 42' S. Long. 53 12' W. 4259 m. (Plate XVII.) 

 Diatomaceous mud. This sample is similar in constitution to the preceding. Some of the mineral 

 grains are 0-3 mm. in diameter though the average is much lower ; they are mostly angular in shape but 

 some are fairly rounded. Broken diatoms provide much of the finer material, in which whole frustules 

 of Coscinodiscus, Thalassiosira and Fragilaria are conspicuous. Broken tests of Globigerina are occa- 

 sionally seen. The sample is lighter in colour than most examples of diatomaceous mud. 



Station WS 204. 26. iv. 28. Lat. 56 27' S. Long. 54° 22' W. 3328 m. (Plate XVII.) 

 Diatomaceous mud. This light brown mud has a considerable proportion of mineral grains which 

 range in size from exceedingly small to about 0-1 mm. in diameter. Angular grains of quartz and 

 green hornblende are conspicuous. The fine material consists in great part of diatom debris among 

 which Coscinodiscus, Thalassiosira and Fragilaria are of common occurrence. A few broken and worn 

 tests of Globigerina and Radiolaria are noted. 



Station WS 205. 27. iv. 28. Lat. 55 49' S. Long. 56 18' W. 4207 m. (Plate XVII.) 

 Diatomaceous mud. This sample is essentially similar to that from St. WS 204 in general con- 

 stitution. The angular mineral grains (including quartz and green hornblende) are generally small. 

 Light-coloured flocculent aggregates which enclose the smallest mineral particles, contain broken 



