SEA-FLOOR DEPOSITS. PART I 347 



Station WS 676. 10. vii. 31. Lat. 08 17' S. Long. 79 01' 30" W. 29 m. (Plate XXII.) 

 Diatomaceous mud. A black mud in which the flocculent aggregates are in excess of the mineral 

 constituent. The former contain resting spores and diatom debris, besides whole frustules of 

 Coscinodiscus (large and abundant), Actinoptychus and Naviada. The spores and the flocculent matter 

 are almost black, especially the denser portions of the latter, a feature which is presumably due to 

 local peculiarities of decomposition. Textularian Foraminifera and fragments of Radiolaria also occur. 

 Most of the mineral grains are extremely small, but some range up to a diameter of about o-i mm. ; 

 they include angular grains of quartz and volcanic glass. 



Station WS 677. 10. vii. 31. Lat. 08 19' 30" S. Long. 79 05' 45" W. 45 m. (Plate XXII.) 

 Diatomaceous mud. The general constitution of this deposit is very similar to that last described, 

 but the flocculent matter is green and the spores remain brown. Among diatoms, Coscinodiscus is 

 large and abundant, Actinoptychus and Navicula are less plentiful. Textularian and rotaline Fora- 

 minifera are of frequent occurrence. Mineral grains, present in subordinate quantity, are mostly very 

 small, but quartz grains up to o-i mm. and splinters of volcanic glass up to 0-2 mm. are noted. 

 Station WS 678. 10. vii. 31. Lat. 08 35' 30" S. Long. 78 57' W. 54 m. (Plate XXII.) 

 Diatomaceous mud. This sample presents no essential difference from the last, though some of the 

 quartz grains attain a greater size, namely, about 0-25 mm. in diameter. Otherwise there is the same 

 excess of flocculent matter over the mineral constituents and the same assemblage of diatoms. 



Station WS 680. 10. vii. 31. Lat. 08 44' S. Long. 79 15' W. 91m. (Plate XXII.) 

 Fine sand. A green sandy deposit with many mineral grains of about 0-25 mm. in diameter. They 

 include angular grains of quartz (up to 0-4 mm. diameter), prismatic grains of green hornblende 

 (0-25 mm. long), brown hornblende of the same habit and size, and splinters of volcanic glass (o-i mm. 

 across). The larger grains are in excess of the finer material. There is a small amount of green, granular, 

 flocculent matter which gives colour to the sand and the liquid. Resting spores and fragments of 

 Coscinodiscus are the only organic remains recognized. 



Station WS 686. 17. vii. 31. Lat. 09 25' 30" S. Long. 8o° 22' W. 4206 m. (Plate XXII.) 

 Diatomaceous mud. A grey-green mud in which the flocculent material is in excess compared 

 with the mineral constituent. The mineral grains include quartz (about 005 mm. diameter), green 

 hornblende (prismatic grains up to o-i mm. in length) and splinters of volcanic glass. The principal 

 diatoms in the flocculent material are Coscinodiscus, Actinoptychus and Achnanthes. 



Station WS 689. 18. vii. 31. Lat. o7°oi'S. Long. 8i° 09' W. 2093 m. (Plate XXII.) 

 Diatomaceous mud. A green mud very similar to the last, but with perhaps a larger proportion of 

 mineral grains which include quartz (o-i mm.), green hornblende (o-i mm.) and volcanic glass 

 (0-05 mm.). The flocculent material is largely diatomaceous in character; it contains whole frustules 

 of Coscinodiscus (large and abundant) together with small rotaline Foraminifera. 



Station WS 692. 19. vii. 31. Lat. 06 29' 15" S. Long. 8o° 33' W. 25 m. (Plate XXII.) 

 Medium sand. The sample is a small quantity of sand with shell fragments. The minerals include 

 quartz in angular grains up to 0-4 mm. in diameter, flakes of white mica 0-5 mm. across, and opaque 

 grains with about the same diameter. Large frustules of Coscinodiscus are present. 



Station WS 694. 19. vii. 31. Lat. 06 38' S. Long. 8o° 49' 54" W. 1216 m. (Plate XXII.) 

 Diatomaceous mud. The green flocculent material contains brown resting spores and diatom 

 debris, among which many whole frustules of Coscinodiscus, Actinoptychus, Synedra and Achnanthes 

 are noted. The mineral grains are usually very small, but some angular grains of quartz, brown horn- 

 blende and volcanic glass reach a diameter of about o- 1 mm. 



Station WS 696. 20. vii. 31. Lat. 06 54' 48" S. Long. 8i° 02' W. 1901m. (Plate XXII.) 

 Diatomaceous mud. This deposit has the same general characters as the foregoing sample. The 

 flocculent material is in excess over the mineral constituent and contains whole frustules of Coscino- 

 discus, Triceratium and Navicula, the first named being most numerous. The silicoflagellate Dictyocha 



