324 DISCOVERY REPORTS 



hornblende and glaucophane occur. The bulk of the deposit consists of flocculent material which 

 surrounds the sand grains and diatoms. Among the latter are species of Fragilaria, Rhizosolenia, 

 Thalassiosira and Coscinodiscus. Some of the diatoms retain their protoplasmic contents, and much 

 of the flocculent matter is doubtless of organic origin. 



Station 212. 16. iv. 27. Lat. 6i° 15' S. Long. 64 42' 50" W. 3350 m. (Plate XVII.) 

 Diatomaceous mud. A brown mud, essentially similar to that from St. 211, but the mineral grains 

 attain a larger size, about o-i mm. in diameter. The occurrence of quartz, green hornblende and 

 white mica is noted. The organic material is chiefly diatomaceous but some arthropod remains and 

 eroded tests of Globigerina occur. 



Station 228. 2. v. 27. Lat. 53 33' S. Long. 61 ° 49' 30" W. 660 m. (Plate XVIII.) 

 Diatomaceous mud. A grey mud with abundant detrital grains up to o-i mm. diameter. Quartz 

 grains preponderate but occasional grains of hypersthene are seen. Large (up to o-i mm.) centric 

 diatoms (e.g. Coscinodiscus), navicular forms (especially Fragilaria) and sponge spicules are present. 

 Flocculent material is conspicuous, but not in such large proportion as in the foregoing samples. 



Station 230. 5. v. 27. Lat. 53 17' S. Long. 6o° 25' W. 675 m. (Plate XVIII.) 



Terrigenous mud. This grey mud has an abundance of very small mineral grains (quartz and 



occasionally hypersthene) in a matrix of flocculent material which is more granular in appearance 



than usual. Recognizable organic remains are virtually absent. 



Station 235. 29. v. 27. Lat. 50 45' S. Long. 56 18' 30" W. 600 m. (Plate XVII.) 

 Sand. A fine-grained sand or silt, some of the constituent grains (chiefly quartz) reaching a 

 diameter of 0-25 mm. Fragments of green hornblende are smaller and less numerous. A few Fora- 

 minifera and diatoms occur, but organic remains other than sponge spicules are scarce. The pre- 

 servative liquid has acquired a slight greenish tinge. 



Station 236. 29-30. v. 27. Lat. 50 35' 30" S. Long. 55 59' 15" W. 612 m. (Plate XVII.) 



Station 237. 30. v. 27. Lat. 50 17' 40" S. Long. 55 31' 30" W. 904 m. (Plate XVII.) 

 Sand. The samples from Sts. 236 and 237 are so similar that they may be described together. The 

 sand grains, mostly quartz, reach a diameter of 0-5 mm. ; some green hornblende is present. Large 

 opaque grains, which form a dark layer in the sediment, together with smaller yellow-green grains 

 show the characters of glauconite. Flocculent matter is present in small amount. The organic 

 fraction includes some Foraminifera (especially Globigerina), centric diatoms and sponge spicules. 

 Some of the latter are infilled with yellow-green " glauconitic " material which shows aggregate 

 polarization between crossed nicols. 



Station 263. 19. vii. 27. Lat. 33 06' S. Long. 17 08' W. 461 m. (Plate XVII, inset.) 

 Glauconitic mud. The material has settled into layers during storage. The upper part consists 

 of homogeneous, extremely fine-grained, flocculent material with a few sponge spicules and occa- 

 sional mineral grains. The lower layer contains abundant Globigerina and some rounded grains of 

 glauconite, up to o- 1 5 mm. diameter. The fine-grained constituent apparently consists of comminuted 

 foraminiferal tests and coccoliths with a considerable proportion of protoplasmic debris, the latter 

 having a greenish tinge. Some of the Globigerina shells are infilled with glauconite. 



Station 264. 19-20. vii. 27. Lat. 33 06' S. Long. 16 55' E. 645 m. (Plate XVII, inset.) 

 Glauconitic mud. A "mixed" deposit consisting of muddy flocculent material with a con- 

 siderable proportion of mineral grains and foraminiferal tests. The mineral fragments (chiefly 

 quartz) reach a diameter of o- 1 mm. Some bright green glauconite grains, rounded to angular in 

 shape, have about the same average size, but one grain measured 0-25 mm. in diameter. The 

 Foraminifera often retain their protoplasmic contents ; Globigerina and Frondicularia were noted as 

 reaching a diameter of 0-2 mm. Coccoliths are frequently seen in the finer material. 



