SEA-FLOOR DEPOSITS. PART I 327 



Station WS 39. 23. xii. 26. Lat. 54 08' S. Long. 35° 43' W. 237 m. (Plate XIX.) 

 Diatomaceous mud. A grey mud which differs from the preceding sample in the somewhat smaller 

 average size of the sand grains, and the greater proportionate bulk of the flocculent constituent, but 

 otherwise very similar. The greenish tinge of the sediment is due to the presence of green flocculent 

 masses. 



Station WS 40. 7. i. 27. Lat. 55 09' S. Long. 35 58' W. 183 m. (Plate XIX.) 

 Diatomaceous mud. 



Station WS 41. 7. i. 27. Lat. 54° 32' 45" S. Long. 36 43' 45" W. 140 m. (Plate XIX.) 

 Diatomaceous mud. 



Station WS 42. 7.1.27. Lat. 54° 41' 45" S. Long. 36 47' W. 175 m. (Plate XIX.) 

 Diatomaceous mud. 



Station WS 43. 7-8. i. 27. Lat. 54 54' S. Long. 36 50' W. 200 m. (Plate XIX.) 

 Diatomaceous mud. These four samples are very similar, and are typical of diatomaceous muds 

 in general. The mineral grains (quartz and green hornblende) are usually small, but some attain 

 diameters up to 0-2 mm. The detrital grains are enclosed in greenish masses of flocculent material 

 which contains small diatoms. 



Station WS 45. 8. i. 27. Lat. 54 38' 30" S. Long. 37 30' 55" W. 180 m. (Plate XIX.) 

 Diatomaceous mud. A grey mud enclosing some hard black pebbles, 1 cm. in diameter. There 

 are abundant detrital grains including green hornblende up to 0-2 mm. in diameter, while a few reach 

 0-5 mm. across. Centric diatoms are conspicuous, and sponge spicules are frequent in occurrence. 

 The finer material includes diatom debris and indeterminable flocculent matter. 



Station WS 46. 8. i. 27. Lat. 54 20' 15" S. Long. 37 32' 30" W. 194 m. (Plate XIX.) 

 Diatomaceous mud. A grey mud with small black pebbles, essentially like the preceding deposit. 

 A fair proportion of mineral grains is enclosed in fine-grained flocculent material which contains the 

 usual diatoms. Some grains of quartz and green hornblende reach a diameter of o-i mm. 



Station WS 47. 9. i. 27. Lat. 54° 22' S. Long. 37 50' W. 160 m. (Plate XIX.) 

 Diatomaceous mud. A grey mud, paler in colour than the preceding sample, but of essentially 

 similar character. Detrital grains, especially quartz and (more rarely) green hornblende, form a 

 considerable bulk in the deposit ; they are mostly below 0-05 mm. in diameter, but some reach 0-25 mm. 

 Centric diatoms are conspicuous in the flocculent "matrix". 



Station WS 48. 9. i. 27. Lat. 54 24' S. Long. 38 09' W. 224 m. (Plate XIX.) 

 Diatomaceous mud. A grey mud when dry, greenish grey when wet. This sediment is almost a 

 diatom ooze with centric (up to 0-2 mm. in diameter), navicular and elongate diatoms, together with 

 some sponge spicules, but there is a considerable quantity of green flocculent matter. There are few 

 mineral grains and those are mostly of small size. A fragment of rock occurs in the sample, measuring 

 2-5 by i"3 cm.; in thin section this is seen to be a tuff containing fragments of felspar and green 

 hornblende. 



Station WS 49. 9. i. 27. Lat. 54 28' S. Long. 38 22' 15" W. 223 m. (Plate XIX.) 

 Diatomaceous mud. This sample is darker in colour than the preceding, and the preservative 

 liquid has acquired a green tinge. There are abundant detrital grains, mostly less than 0-05 mm. in 

 diameter, but some (including green hornblende) greater than o-i mm. These and large centric 

 diatoms are embedded in flocculent material of the usual character. 



Station WS 50. 9. i. 27. Lat. 54 30' 30" S. Long. 38 40' 30" W. 230 m. (Plate XIX.) 



Diatomaceous mud. The sample has dried to a light grey colour. The pale colour appears to be 



due to the relative scarcity of dense flocculent masses ; the fine material is abundant, but consists 



almost entirely of comminuted diatom tests and mineral grains. Frustules of Coscinodiscus and 



Fragilaria are abundant, Rhizosolenia less plentiful and sponge spicules are present in small quantity. 



