54 THE DEPTH AND MARINE DEPOSITS OF THE PACIFIC OCEAN. 



Calcium carbonate : 70.40 per cent, pelagic and bottom-living Forara- 

 inifera, Ostracodes, rhabdoliths, and coccoliths. 



Residue : 29.60 per cent, dark chocolate-brown, very clayey: — 



Siliceous Organisms (traces) ; out of 22 grams of dried ooze there remained 

 after washing only one or two centigrams of mineral particles and siliceous 

 organisms of appreciable size, so that the part played by them is insignificant. 

 The more abundant siliceous organisms are arenaceous Foraminifera and 

 brown, imperfect casts of pelagic Foraminifera. Sponge spicules and Radio- 

 laria are present, but very rare. 



Minerals (traces) ; one piece of palagonite, 2 mm. in diameter, a few 

 manganese grains, 0.3 mm. in mean diameter, one or two fragments of 

 colorless volcanic glass, crystals of plagioclase, and a little magnetite are all 

 that could be detected. This deposit contains a good many pieces of rock, 

 ranging from | inch to 2 inches in diameter. Most of them have very 

 blunted edges, though they cannot be described as rounded ; one or two 

 pieces, on the other hand, are quite angular. The rock is very dark gray, 

 nearly black, and weathers brown ; it is an augite-andesite, the glassy base 

 of which has decomposed and has been changed into an amorphous ferru- 

 ginous clay. Some pieces have " druses " coated with a thin layer of mangan- 

 ese oxide. 



Fine Washings (29.60 per cent), chocolate-brown, flocculent clay, remark- 

 ably free from mineral particles and organic remains. 



The following is a list of the species of Foraminifera observed in the 

 deposit from this station : — 



Bilomlina depressa, d'Orb. 



" " var. murrhyna, Schw. 



" ringens (Lamk.), var. denticulata, 



Brady. 

 Biloculina elongata, d'Orb. 

 Spiroloculina acutimargo, Brady. 

 M'lliolina venusta (Kar.). 



" tricarinata (d'Orb.). 



" oblonga (Montag.). 

 Reophax nodulosa, Brady. 

 Trochammina proteus, Kar. 

 Cydammina pusilla, Brady. 

 Verneuiliim pygmaea (Egger). 

 Gaudryina pupoides, d'Orb. 

 Bulimina elegans, d'Orb. 



" " var. exilis, Brady. 



Virgulina subdepressa, Brady. 



Vlrgidiiia schreibersiaria, Czjzek. 

 Cassidulina subglobosa, Brady. 



" crassa, d'Orb. 



Lagena acuta (Ess.), var. 

 " alveolata, Brady. 

 " desmophora, Ry. Jones. 

 " exsculptn, Brady. 

 " globosa (Montag.). 

 " fimbrinta, Brady. 

 Cristellaria convergens, Bornem. 

 Uvigerina aspenda, Czjzek. 

 Globigerina conglobata, Brady. 

 " sacculifera, Brady. 



Globigerina rubra, d'Orb. 

 " bulloides, d'Orb. 



" " var. triloba, Rss. 



" dubia, Egger. 



