512 Mr. J. Murray on Oceanic Deposits examined 



long. 149° 30' W. In the top of the tube a Olobigerina-ooze of a 



light brown colour containing: — Very many pelagic Foraminif era 



and Coccoliths ; amorphous clayey matter and many small yellow 



crystals and particles of the peroxide of manganese. In the lower 



part of the tube a dark chocolate clay containing : — Very many small 



yellow crystals ; pieces of a red and yellow mineral and pumice 



particles ; many small sharks' teeth ; amorphous clayey matter, and 



great numbers of manganese particles and grains. 



The transitions from the dark chocolate clay at the bottom to the light 



brown Olobigerina-ooze on the top w 7 as very gradual, the lighter colour 



and the carbonate of lime increasing pari passu. The yellow crystals and 



manganese particles were most abundant in the lower portions of the 



tube. Radiolaria and other siliceous remains were almost wanting in 



this bottom. 



The trawl brought up about half a ton of manganese nodules, some 

 small pieces of pumice, several sharks' teeth, one of which was 3 inches 

 across the base. Some of these were deeply and others only slightly 

 coated with manganese. 



Sounding 298. 17th September, 1875. 2325 fathoms. Lat. 15° 7' S., 

 long. 149° 41' W. This bottom nearly the same as described for 

 yesterday. It had, however, more mineral particles and fewer of 

 the small yellow crystals in all its parts ; also few manganese par- 

 ticles. 



Sounding 299. 18th September, 1875. 1525 fathoms. Lat. 17° 13' S., 

 long. 149° 33' W. A grey mud containing : — Amorphous clayey 

 matter ; many fine and coarse mineral particles of a white, red, and 

 yellow colour ; many pelagic Foraminif era ; Coccoliths and Ehabdo- 

 liths ; one or two portions of Eadiolaria. 



Off Tahiti, Society Islands. 



Sounding 300. 20th October, 1875. 420, 590, 620, and 680 fathoms. 

 In each case a grey or blue mud containing : — Very many particles 

 of volcanic sand and amorphous matter ; debris of coral ; pelagic and 

 other Foraminif era ; larval Gasteropocls and Lamellibranchs ; Echini- 

 spines &c. In the tw T o deeper ones there was a red surface-layer. 

 Just outside the reefs at Tahiti there was a coral-mud containing a few 



mineral particles ; inside the reefs there was a soft blue mud. 



Tahiti to Valparaiso. 



Sounding 301. 4th October, 1875. 1940 fathoms. Lat. 18° 40' S., long. 

 149° 52' "W. A grey Olobigerina-ooze containing : — Very many 

 pelagic Foraminif era ; Coccoliths and Ehabdoliths ; some amorphous 

 clayey and calcareous matter ; some manganese grains ; a good many 

 rather coarse mineral particles of a brown and black colour ; a good 



