THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 75 



bottom-living, but mostly pelagic : Globigerina and Pulvinulirm; these shells are 

 all colored reddish-brown by oxide of iron. As the clayey matter has dis- 

 appeared, an estimation of the carbonate of calcium would have been useless. 



Minerals (traces), angular; mean diameter 0.02mm., quartz and mag- 

 netite are present in equal quantities ; one or two greenish particles may be 

 attributed to a member of the chlorite family. 



Siliceous Organis77is; Sponge spicules are the only true siliceous or- 

 ganisms ; there are also a good many yellowish and brown imperfect casts of 



Foraminifera. 



Station 4642, 7th November, 1904. 



Lat. 1°30.5'S. ; long. 89° 35' W.; depth, 300 fathoms. 



CALCAREOUS SAND: very little material, — incoherent sand, formed of 

 fragments (mean diameter, 2 mm.) of Lamellibranch and Gasteropod shells, 

 accompanied by fragments of Corals, and entire specimens of surface and 

 bottom-living Foraminifera, together with young individuals of Gasteropoda. 

 Very few minerals are present ; plagioclase, augite, a red product of the 

 decomposition of some ferruginous mineral, and a little magnetite. 



Station 4693, 14th December, 1904. 

 Lat. 26° 30.1' S.; long. 105° 45.2' W.; depth, 1142 fathoms. 



GLOBIGERINA OOZE : gray, granular, incoherent, with many irregular 

 fragments of manganese nodules; some of the Foraminifera (especially 

 Orbulina imiversa) are visible to the naked eye. 



A few Sponge spicules and arenaceous Foraminifera were observed. 



Many fragments of pumice and other volcanic rocks, and fragments of 

 manganese nodules, are present ; the mineral particles observed are angu- 

 lar, with a mean diameter of 0.3 ram. ; augite, plagioclase, green chlorite, 

 with minute splinters of volcanic glass, also a brown opaque ferruginous 

 product of the decomposition of some basic mineral, and a little magnetite. 



Station 4723, 16th January, 1905. 

 Lat. 10° 14.3' S. ; long. 107° 45.5' W. ; depth not mentioned. 



GLOBIGERINA OOZE: the material is very granular and incoherent; 

 principally pelagic Foraminifera, with many small individuals ; a few bottom- 

 living forms (Rotalidae), a few Sponge spicules and Radiolaria ; and a few 

 manganese grains, 0.1 to 0.5 mm. in diameter, angular fragments of augite, 

 and one or two splinters of volcanic glass. 



