REPORT ON THE DEEP-SEA DEPOSITS. 
145 
Residue. 
Siliceous Organisms. 
S (I'OO %), Sponge spicules, Ra- 
diolaria, imperfect casts of 
Foraminifera, Astrorhizidie, 
Lituolidce, a few Diatoms. 
9 |(1'00 %), Radiolaria, Sponge 
I spicules, Lituolidse. 
i few Radiolaria, Lituoliclm. 
I'OO %), one or two Radiolaria, 
fragments of Sponge spicules, 
HaploTphragmium . 
Minerals. 
Fine Washings. 
(I'OO %), m. di. 0'06 mm., 
angular ; felspar, hornblende, 
magnetite, magnetic spher- 
ules, pumice, a few manganese 
grains, bronzite spherules. 
(I'OO %), m. di. 0'06 mm., an- 
gular ; fragments and crystals 
of sanidine and plagioclase 
often inclosed in wtreous 
matter, augite, magnetite, 
gi-eenish chloritic particles, 
manganese grains. 
Manganese grains. 
Manganese grains. 
(I'OO %), m. di. 0',20 mm., 
angular ; much plagioclase 
and sanidine, hornblende, 
magnetite, augite, very rarely 
quartz and olivine. 
(1-00%), m. di. I'OO mm., 
rounded and angular ; a few 
fragments of volcanic rocks 
and vesicular lapilli. 
(I'OO %), m. di. 0'50 mm., 
angular and rounded; felspar, 
magnetite, augite, olivine, 
scoriaceous particles and other 
fragments of volcanic rocks. 
(5 '46 %), amorphous matter, 
with small mineral particles 
and fragments of scoriae and 
siliceous organisms. 
(2 '39 %), amorphous matter, 
fine mineral particles, and 
a few minute fragments of 
siliceous spicules. 
A trace of amorphous matter. 
(1'20 %), a small quantity of 
flocculent matter and minute 
fragments of minerals. 
(0'96 %), a small quantity of 
flocculent matter and a few 
fragments of minerals. 
(2 '44 %), flocculent organic 
matter and minute fragments 
of minerals. 
Additional Observations. 
This is one of the purest Globigerina Oozes obtained 
by the Challenger and is almost wholly composed of 
the dead shells of surface organisms. The general ap- 
pearance of the deposit is represented in PI. XII. fig. 1. 
On comparison with fig. 3 it will be noticed that the 
majority of the shells are, in this deposit, much 
smaller and thinner than in the deposit nearer the 
equator. The younger specimens are much more 
numerous and the species which predominate are 
different. These remarks hold good also for the 
specimens taken on the surface. A few pumice frag- 
ments were found in the washings of a large quantity 
of deposit. 
The tube had sunk nearly 10 inches (25 cm.) into the 
bottom and brought up over one litre of the deposit. 
Many of the Pteropod and Heteropod shells are quite 
black and others have a brown colour from a coating of 
manganese. The shells of the pelagic Molluscs were 
more abundant in the surface than in the deeper layers 
of the deposit, only a few being observed in the ooze at 
the lower end of the tube. Many of the Foraminifera 
are brown coloured from a deposit of oxide of iron on 
their surface. Note that the shells of Pteropods and 
Heteropods are abundant in this deposit, but are rare 
at the preceding station, which is 575 fathoms deeper. 
The sounding tube came up with some traces on the out- 
side which indicated that it had sunk about a foot (30 
cm. ) into the bottom. The deposit is similar to that at 
Station 339. 
The sounding tube came up empty, with the exception 
of a few Pteropod shells, Foraminifera, and small 
particles of peroxide of manganese. On the outside of 
the tube there were several black streaks, which on 
examination were found to be due to peroxide of 
manganese. 
The hydra sounding tube was used, and brought up only 
a small quantity of the deposit which was chiefly 
composed of Pteropods, Heteropods, and pelagic 
Foraminifera. Many of the Pteropods are covered 
with a thin coating of peroxide of manganese. Many 
of the shells are macroscopic. There was an insufficient 
quantity for analysis. 
The sounding tube brought up two pieces of Coral coated 
with manganese. There was a little ooze on one of 
the swabs, from which the analysis and description is 
taken ; probably the percentage of carbonate of lime is 
too high. The dredge was empty. 
This sand is chiefly composed of calcareous Algae, frag- 
ments of Gasteropod and Lamellibranch sheUs, with a 
few fragments of Millepores, Echinoderms, very rarely 
Polyzoa, and Foraminifera. The fragments are aU 
rounded and poli.shed by the action of the waves, and 
have a mean diameter of about 1 '3 mm. 
The sand of Long Beach would appear to have its 
origin from the broken fragments of calcareous Algie 
carried bjr the waves from this locality and similar 
depths around the island. 
(deep-sea deposits chall. exp. — 1890.) 
19 
Tristan da Cunha to Ascension Island— cowiMiwcd. Gif Ascension. 
