56 THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 



Pulvinulina, OrbuUna) and their fragments form the greater part of the cal- 

 cium carbonate, with one or two bottom-living forms {Biloculina depressa) and 

 a few Echinoid spines. 



Residue : 66.67 per cent : — 



Siliceous Organisms (0 per cent) ; none could be detected. 



Minerals (5 per cent), all the particles are angular, and their mean 

 diameter is a little under 0.1 mm. Of determinable mineral particles com- 

 mon augite is the most frequent, while felspar is also very abundant, and 

 could be accurately determined as labradorite (Abj AnJ. There are also 

 many minute fragments of magnetite. The remaining portion is represented 

 by the brown product of decomposition of some ferro-magnesian mineral. 

 The fragment of rock is a hard, vitreous, black, volcanic glass, without any 

 trace of crystallization. 



Fine Washings (61.67 per cent), brown, amorphous clayey matter, 

 with numerous minute mineral particles. 



No. 25. Station 4517,* 22nd December, 1904. 

 Lat. 26° 50.9' S.; long. 109° 12.5' W. ; depth, 1723 fathoms. 



GLOBIGERINA OOZE : light-brown, slightly plastic, drying into reddish- 

 brown lumps that have little coherence. 



Calcium caebonate : 63.55 per cent, many species of pelagic Foramini- 

 fera, including numerous small individuals ; one Echinoid spine was detected. 

 Residue : 36.45 per cent, dark brown : — 



Siliceous Organisms (traces), only a few arenaceous Foraminifera and 

 Sponge spicules. 



Minc7-als (2.50 per cent), mostly angular ; augite plays the principal rQle ; 

 magnetite comes next in order of abundance, and there are a good many 

 microlites of basic plagioclase. Volcanic glass was not observed. 



Fi7ie Washings (33.95 per cent), dark-brown clay with minute mineral 

 particles. 



No. 26. Station 4518, 22nd December, 1904. 

 Lat. 26° 47.3' S. ; long. 109° 9.3' W. ; depth, 1770 fathoms. 



GLOBIGERINA OOZE: light brown, plastic, but not sticky; reddish- 

 brown and slightly coherent when dry. 



Calcium carbonate : 53.01 per cent, Foraminifera, most of the indi- 

 viduals being of small size, and Echinoid spines. 



