SEA-FLOOR DEPOSITS. PART I 321 



Station 171. 25. ii. 27. Lat. 62 07' S. Long. 57 03' W. 16 miles off Cape Melville, King 

 George Island, South Shetlands. 1542 m. (Plate XX.) 



Diatomaceous mud. This brownish grey mud contains abundant mineral grains, many ex- 

 ceedingly small and the great majority less than o- 1 mm. in diameter. Besides the quartz grains, 

 prismatic fragments of green hornblende and splinters of brown volcanic glass are noted. There is a 

 large proportion of indeterminate flocculent material which contains small diatoms (whole and 

 fragmentary frustules of Coscinodiscus, Fragilaria and Rhizosolenia) together with sponge spicules. 



Station 172. 26. ii. 27. Lat. 62 59' S. Long. 6o° 28'W. Off Deception Island, South Shetlands. 



525 m. (Plate XX.) 



Gravel. The sample consists of black pebbles, presumably of volcanic rock, on some of which are 



adherent polyzoa. 



Station 175. 2. iii. 27. Lat. 63 17' 20" S. Long. 59 48' 15" W. Bransfield Strait, South Shet- 

 lands. 200 m. (Plate XX.) 



Sand. The sample consists of a small quantity of sand. The particles are mainly coarse, the larger 

 grains reaching a diameter of 0-5 mm., but some of the material is finer and shows a variety of 

 minerals. Quartz is most abundant, while hornblende and volcanic glass are noted among the coloured 

 grains. No organic remains were seen. 



Station 180. 11. iii. 27. 17 miles west of northern point of Gand Island, Palmer Archipelago. 

 160 m. (Plate XX.) 



Terrigenous mud. This pale grey mud consists almost entirely of detrital mineral grains, chiefly 

 quartz, but green hornblende (up to o-2 mm. diameter) and occasional splinters of volcanic glass are 

 conspicuous. Only occasional diatoms and sponge spicules are seen. 



Station 185. 16. iii. 27. Gerlache Strait, Palmer Archipelago. 3-5 miles S 119 E of Cape van 

 Wycks, Anvers Island. 598 m. (Plate XX.) 



Diatomaceous mud. Roughly half the bulk of this brownish grey mud consists of fairly angular 

 detrital grains which reach a diameter of o-i mm. Occasionally frustules of Coscinodiscus are 

 larger than this. The other half consists of flocculent material which includes tiny mineral grains, small 

 diatoms (Fragilaria, etc.), fragments of sponge spicules and indeterminate debris. 



Station 187. 18. iii. 27. Lat. 64 48' 30" S. Long. 63 31' 30" W. Neumayr Channel, Palmer 

 Archipelago. Two samples from depths of 200 and 259 m. respectively. (Plate XX.) 



Diatomaceous mud. The sample from 200 m. is a brownish mud consisting of flocculent material 

 with some mineral grains whose diameter is usually less than 0-05 mm. Occasional navicular diatoms 

 and sponge spicules are present. 



The sample from 259 m. is a grey mud, largely of detrital origin, with mineral grains reaching 

 more than 02 mm. in diameter and consisting chiefly of quartz and green hornblende, together with 

 fragments of volcanic glass. Centric diatoms (about 0-05 mm. diameter), occasional Foraminifera 

 and sponge spicules are noted. 



Station 191. 25. iii. 27. Gerlache Strait, Palmer Archipelago. 2-5 miles Nii4°E of Cape 

 Astrup, Wiencke Island. 310 m. (Plate XX.) 



Diatomaceous mud. A light grey mud with abundant detrital minerals, some of which are 

 0-2 mm. in diameter, including grains of green hornblende, some of which are idiomorphic. These 

 are enclosed in flocculent material, apparently organic debris, which also contains small diatoms, 

 both centric and navicular forms, but these are not abundant. 



Station 192. 27. iii. 27. Lat. 64 14' S. Long. 6i° 49' W. Off Cape Kaiser, Brabant Island, 

 Palmer Archipelago. 800 m. (Plate XX.) 



Diatomaceous mud. This brownish grey mud is mainly a mass of flocculent material, apparently 

 organic debris, which encloses small centric and navicular diatoms (0-02 mm.) together with com- 

 minuted frustules. Some of the material may be mineral grains, but determination of these tiny 



