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THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 79 
It contains no calcium carbonate, and besides the siliceous organisms and 
manganese grains, only a few minerals were observed in the clayey matter. 
Another sample consists of: (1) a small piece of volcanic rock in process 
of transformation into palagonite, (2) a flat piece of palagonite much im- 
pregnated with manganese, and (3) a small manganese nodule. 
