THE DEPTH AND MAEINE DEPOSITS OF THE PACIFIC OCEAN. 51 



No. 15. Station 4676, 5th December, 1904. 

 Lat. 14° 28.9' S. ; long. 81° 24' W. ; depth, 2714 fathoms. 



RED CLAY: brown, plastic and sticky, drying into hard, gray lumps 

 with a reddish tinge. 



Calcium carbonate : per cent. 

 Residue : 100 per cent : — 



Siliceous Organisms (traces), a few Sponge spicules and Diatoms. 

 Minerals (traces), one or two minute manganese grains, and mineral 

 particles too small to be determined. 



Fine Washings (nearly 100 per cent), brown flocculent clay, with very 

 few minute mineral particles and remnants of Sponge spicules. 



No. 16. Station 4679, 7th December, 1904. 

 Lat. 17° 26.4' S. ; long. 86° 46.5' W. ; depth, 2485 fathoms. 



RED CLAY : typical, light-brown clay, very plastic and sticky, drying into 

 hard lumps, reddish in hue. 



Calcium carbonate : per cent. 

 Residue : 100 per cent : — 



Siliceous Organisms (traces), a few Sponge spicules only. 



Minerals (traces) ; most of the particles are so small (0.005 mm. in diam- 

 eter) that they cannot be determined. One large crystal of felspar, with 

 perfect prismatic faces, was observed, and also a few small manganese grains. 

 An elongated fragment of pumice, one inch long, is the only macroscopic 

 element present. 



Fine Washings (nearly 100 per cent), amorphous, light-brown clayey 

 matter, with many very minute mineral particles. 



No. 17. Station 4681, 8th December, 1904. 

 Lat. 18° 47.1' S. ; long. 89° 26' W. ; depth, 2395 fathoms. 



RED CLAY: typical, light brown clay, very plastic, forming extremely 

 hard lumps when dried ; shining brown streak. 



Calcium carbonate : 4.23 per cent, Foraminifera belonging to the 

 genus PidoinuUna, and Fishes' teeth. 

 Residue : 95.77 per cent : — 



Siliceous Organisms (traces). Sponge spicules. 



Minerals (traces), a few irregular manganese grains, and angular frag- 

 ments of felspar, 0.2 mm. in diameter. 



