on board H.M.S. ' Challenger. 3 477 



like mineral of a red colour (a silicate) ; a few white mineral par- 

 ticles. 

 Sounding 50. 4th March, 1873. 1900 fathoms. Lat. 21° 38' N., long. 

 44° 39' W. A Globigerina-ooze containing : — Very many pelagic 

 Foraminifera, Coccoliths, and Ehabdoliths ; many red-coloured 

 mineral particles, and a few manganese particles. 



Sounding 51. 5th March, 1873. 1950 fathoms. Lat. 21° 1' K, long. 

 46° 29' W. A Globigerina-ooze of a red colour containing : — Very 

 many pelagic Foraminifera, Ehabdoliths, and Coccoliths ; many very 

 fine white-coloured mineral particles (sanidin) ; a good many small 

 manganese particles, to which the colour of the sounding is to some 

 extent due. 



Sounding 52. 6th March, 1873. 2325 fathoms. Lat. 20° 49' N., long. 

 48° 45' W. A Globigerina-ooze of rose-colour containing : — Very 

 many pelagic Foraminifera, Coccoliths, and Ehabdoliths ; much 

 amorphous matter, and very many fine white mineral particles ; a 

 few Eadiolarian remains. 



Sounding 53. 7th March, 1873. 2435 fathoms. Lat. 20° 39' N., long. 

 50° 33' W. A red clay containing: — Much amorphous clayey 

 matter ; many fine white and red mineral particles ; a few manga- 

 nese particles ; a good many remains of pelagic Eoraminifera, Coc- 

 coliths and Ehabdoliths ; a few Eadiolarians. 

 The dredge brought up some grey-coloured concretions covered with 



manganese, also a few sharks' teeth and valves of a Sccllpellum covered 



with a thin coating of manganese. 



Sounding 54. 8th March, 1875. 2385 fathoms. Lat. 20° 7' K, long. 

 52° 32' "W". A red clay containing : — Much amorphous matter ; 

 many exceedingly fine mineral particles ; many pelagic Foraminif era, 

 Coccoliths, and Ehabdoliths ; a few manganese grains. 



Sounding 55. 10th March, 1873. 2675 fathoms. Lat. 19° 41' N., long. 

 55° 13' W. A red clay containing : — Much amorphous clayey 

 matter ; many very small crystalline particles ; a few whole and 

 some broken parts of pelagic Foraminifera. 



Sounding 56. 11th March, 1873. 3000 fathoms. Lat. 19° 15' N., long. 

 57° 47' W. A red or grey clay containing : — Amorphous matter 

 and exceedingly fine mineral particles ; a small piece of shell and a 

 portion of a siliceous spine were the only traces of organisms; a few 

 manganese particles. 



Sounding 57. 12th March, 1873. 2975 fathoms. Lat. 18° 56' N., long. 

 59° 35' "W. A red clay containing : — Much amorphous matter and 

 very many exceedingly fine mineral particles ; a few remains of 

 pelagic Foraminifera ; one or two portions of a siliceous spine. 



Sounding 58. 13th March, 1873. 3025 fathoms. Lat. 18° 54' N"., long. 



