REPORT ON THE DEEP-SEA DEPOSITS. 
49 
Residue. 
Additional Observations. 
Siliceous Organisms. 
Minerals. 
Fine Washings. 
' 
(I'OO %), Sponge spicules, Eadio- 
laria, Lituolidee, a few 
Diatoms. 
(I'OO %), m. di. 0'06 mm., 
angular ; a few fragments of 
felspar and volcanic glass. 
(8 '64 %), amorphous matter, 
fragments of siliceous organ- 
isms, and a few fragments of 
minerals. 
Some of the organisms are macroscopic. There is a great 
deal of amorphous calcareous matter in the deposit. 
(1’00%), Sponge spicules, Radio- 
laria, Lituolidse, arenaceous 
Textularidse, Diatoms. 
(] '00 %)? m. di. 0'06 mm., 
angular; felspar and volcanic 
glass. 
(8 '32 %), amorphous matter, 
with fragments of siliceous 
organisms and minerals. 
Many of the shells and fragments of other organisms are 
macroscopic, the latter varying in size from 1 to 
20 mm., the majority being from 4 to 6 mm. in 
length. The washings which remain after pas.singthe.se 
deposits through the sieves consist chiefly of the shells 
of pelagic Molluscs and Foraminifera, with broken pieces 
of large calcareous Foraminifera, Serpula tubes. 
Polyzoa, Corals, calcareous Algse, &c. The percentage 
of carbonate of lime is the mean of the analyses of the 
two samples. 
- 
Dredge half full of chalky Coral Mud. 
(I'OO %), Radiolaria, Sponge 
spicules, Lituolidie, one or two 
Diatoms. 
(I'OO %), m. di. 0'06 mm., 
angular; felspar and volcanic 
glass. 
(4 '66 %), some amorphous 
matter, minute fragments of 
minerals, siliceous spicules, 
and organic matter. 
The majority of the particles making up the sand are 
about I or 2 mm. in diameter, but some are much 
larger. Although pelagic Molluscs and Foraminifera 
are present the carbonate of calcium is mostly made 
up of the shells of bottom-living organisms. 
(I'OO %), Sponge spicules, im- 
perfect casts of Foraminifera, 
Diatoms. 
(I'OO %), m. di. 0'15 mm., 
angular and rounded; quartz, 
felspar, a few glassy volcanic 
fragments, black mica. 
(2 '57 %), a small quantity of 
amorphous matter, fragments 
of siliceous!' spicules and 
Diatoms, a few fine glassy 
particles. 
This deposit is chiefly made up of calcareous Algse and 
fragments of Gasteropod and Laniellibranch shells. 
The finer parts appear to be chiefly derived from the 
' decomposition of calcareous Algse. 
(1 '00 %), Sponge spicules, a few 
imperfect casts of Foramini- 
fera, Diatoms. 
(I'OO %), m. di. 0'40 mm., 
angular ; a few particles of 
quartz and glassy volcanic 
fragments. 
(6 '91 %), fine fiocculent amor- 
phous matter, siliceous and 
mineral remains. 
The deposit is made up chiefly of calcareous Algse and their 
broken down parts, with a few of the other organisms 
mentioned ; these latter are fragmentary. The whole 
forms a coarse cement-like mass with a greenish tinge. 
Many of the organisms are macroscopic. 
(1 '00 %), Sponge spicules, one or 
two imperfect casts of Fora- 
minifera, Diatoms. 
(I'OO %), m. di. 0'50 mm., 
angularandrounded ; particles 
of quartz, glassy volcanic 
fragments. 
(7 '82 %), a small quantity of 
amorphous matter, siliceous 
and mineral remains. 
About 50 per cent, of the carbonate of lime in the sand is 
made up of calcareous Algse, the particles measuring 
from 1 to 10 mm. in diameter. Many of the organisms 
are macroscopic. 
(I'OO %), Sponge spicules. 
Diatoms. 
(2'00 %), m. di. 0'80 mm., 
rounded ; quartz, hornblende, 
glassy volcanic particles. 
(10 '23 %), amorphous matter, 
fragments of Sponge spicules 
and Diatoms, small mineral 
particles. 
The residue contained many fragments of coal. It is 
possible that at least some of the minerals found here 
have been discharged from passing ships. 
(I'OO %), Radiolaria, Sponge 
spicules, Haplopliragmium, 
one or two Diatoms. 
(1'00%), m. di. 0'07 mm., 
angular; sanidine, plagioclase, 
volcanic glass, augite, horn- 
blende, magnetite. 
(32 '00 %), amorphous matter, 
minute fragments of minerals 
and siliceous organisms. 
The Foraminifera obtained in this deposit are mostly of 
pelagic origin. Note the decrease in the quantity of 
carbonate of lime with increase of depth and distance 
from the reefs. 
(deep-sea deposits chall. exp. — 1890.) 
■ 
7 
St. Thomas to Ber- 
muda — continued. Off Bermuda. At Bermuda, inside thu reof. Off Bermuda. 
