204 
THE VOYAGE OF H.M.S. CHALLENGER. 
fragments are very abundant in some samples, as are also teeth of sharks. With 
reference to the organisms living on the Red Clay and the Radiolarian Ooze, they 
appear to be the same in nearly all respects in the two regions both as to the species 
and their relative abundance. 
The deposit was first met with in the Western North Pacific, during the voyage 
from New Guinea to Japan, in the deepest sounding taken during the cruise, and, with 
one or two exceptions, the greatest depth hitherto discovered, and still the greatest depth 
from wliich a specimen of the bottom has been procured. As this was a highly character- 
istic Radiolarian Ooze, we will refer to the sample collected at some length. Two sound- 
ings were taken at this station (Station 225, lat. 11° 24' N., long. 143° 16' E.). The first 
.sounding was in a depth of 4575 fathoms, when only a little of the deposit came up 6n 
the outside of the tube. This sounding not being a satisfactory one, a second was taken, 
when the depth was ascertained to be 4475 fathoms. The tube had sunk fully three 
inches into the deposit ; the upper layers were of a red colour, and contained much more 
peroxide of manganese than the lower ones, which were of a pale yellow or straw colour, 
in this respect, as well as in other physical aspects, very much resembling the Diatom 
Oozes found in the Southern Ocean during the cruise towards the Antarctic regions. The 
whole of the lower part of the deposit when it came up had a very compact and laminated 
appearance ; the laminated fragments could be easily broken with the fingers, but it was 
difficult to separate the various components of the deposit the one from the other by 
sliaking the whole in a bottle with water. The Radiolaria, Diatoms, and Sponge spicules 
appeared to be most abundant in the lower layers. The deposit effervesced a little with 
dilute hydrochloric acid, and one or two fragments of pelagic Foraminifera were found 
during the microscopic examination of a large portion of the sample, along with two 
specimens of Ilaplophragmivm fjlohujeriniforme. 
'J'he most abundant mineral particles are angular and more or less rounded fragments 
of volcanic glass in various stages of alteration and of a red-green or yellow colour ; they 
are glossy, and break like resin; some are vesicular, and the vesicles are coated with 
prismatic zeolites. Besides these altered fragments of volcanic glass, there are grey-black 
lapilli of andesite and colourless splinters of pumice. There are also fragments of plagio- 
clases suiTounded with vitreous matter, crystals of augite, grains of magnetite, and a few 
cosmic chondritic and native iron spherules.* 
Argillaceous matter is not very abundant in this sample of Radiolarian Ooze, but 
there are large numbers of little particles formed by agglomerates of the deposit. These 
particles have an irregular form, and do not break up under the action of strong hydro- 
i-hloric acid, which merely removes the iron along with other colouring substances ; 
microwopic examination shows that they are aggregates of the bottom made up of 
Kadiolarians, Sponge spicules, and minute volcanic particles. The tenacity of these little 
' Se« PI. XXIII. 
