REPOET ON THE DEEP-SEA DEPOSITS. 
79 
Residue. 
1 
Additional Observations. 
iliceous Organisms. 
Minerals. 
Fine Washings. 
•00 %), Radiolaria, Sponge 
picules, numerous Diatoms. 
(25-00 %), m. di 0-12 mm., 
angular and rounded ; felspar, 
plagioclase, augite, horn- 
blende, olivine, magnetite, 
brown and red decomposed 
glassy volcanic fragments, one 
or two rounded quartz grains, 
brown and red mammillated 
fragments. 
(15-37 %), fragments of Diatoms 
and minute mineral particles. 
Very little of the deposit was obtained. There were 
several pebbles in the trawl; one fragment, about 3 cm. 
in diameter, is angular ; some of them are vesicular 
augite-andesites, with a vitreous base. In addition 
there were other fragments covered with and cemented 
by manganese ; these consist of lapilli, brown in 
colour and much decomposed. 
•00 %), Radiolaria, casts of 
alcareous organisms, Dia- 
oms. 
(25-00 %), m. di. 0-12 mm., 
angular and rounded ; felspar, 
plagioclase, black mica, born- 
blende, augite, magnetite, 
olivine, glassy volcanic parti- 
cles, red mammillated frag- 
ments. 
(18-66 %), amorphous matter, 
very many fragments of 
Diatoms, and minute mineral 
particles. 
There are in this deposit very fine and perfect casts of 
Foraminifera, fragments of Echini, &c. The carbonate 
of lime organisms are white or of a pale straw colour ; 
with reflected light they are shining and homogeneous; 
with transmitted light some are opaque, some trans- 
parent and yellow-brown. There are no green casts or 
glauconitic particles in the deposit. It is unusual to 
find such perfect casts in the deposit off a volcanic 
island. Some of these casts show aggregate polariza- 
tion. 
There were two dredgings ; many animals, but no 
deposit, were obtained. The bottom seemed to be 
hard and composed of gravel, Polyzoa, and shells. 
The dredge brought up a few specimens of Aphrocallistes. 
The bottom appeared to be of the same nature as that 
at the previous station. 
00 %), Sponge spicules, 
ituolidie, frustules of Dia- 
ms. 
(20-00 %), m. di. 0-15 mm., 
angular ; plagioclase, augite, 
magnetite, hornblende, olivine 
(in some cases altered), lapilli, 
pumice, brown volcanic glass. 
(29-00 %), a small quantity of 
amorphous matter, flocculent 
organic matter, many fine 
mineral particles, fragments 
of Sponge spicules and 
Diatoms. 
During the month of January 1874 the Challenger took 
many soundings and dredgings in the bays, and several 
miles off the coast, of Kerguelen, in depths varying 
from 20 to 150 fathoms. In all cases the deposit was 
a Green Mud, with a strong smell of sulphuretted hydro- 
gen, composed principally of mineral particles and the 
skeletons of siliceous organisms. Generally these muds 
did not effervesce with acid ; sometimes a few spots 
were observed. The carbonate of lime never appeared 
to make up more than 1 per cent. The larger, sized 
mineral particles were found in the soundings nearest 
the coast, while siliceous organisms seemed to be most 
abundant in the soundings furthest from the coast. 
In some cases the deposit was almost entirely made up 
of the basal portions of siliceous sponges, e.g., Rossella 
antarctica. The dredgings along this coast gave many 
animals. 
)0 %), many Sponge spicules 
d Radiolaria. 
(60-00 %), volcanic and otber 
pebbles. 
(5-00 %), amorphous matter 
and fragments of siliceous 
organisms. 
A large number of stones were brought up in the dredge. 
These are fragments of rocks of irregular form and 
varying in diameter from 1 to 7 cm. They are blue- 
black and much overgi'own by Sponges, Serpula, 
Polyzoa, Foraminifera, &c. ; some of the pebbles are 
granite, augite-andesite, basalt filled with delessite. 
•j' %), Radiolaria, Sponge 
(80-00 %), m. di. 0-30 mm., 
angular ; fragments of brown 
and reddish volcanic glass 
often enclosing microliths of 
olivine, plagioclase, augite, 
magnetite. 
(12-42 %), many fine mineral 
particles, a small quantity of 
amorphous matter, fragments 
of Sponge spicules and 
Diatoms. 
This deposit is essentially composed of black volcanic 
sand and remains of organisms. The fragments of 
glass are vesicular, and often decomposed. The dredge 
was used three times and brought up many animals. 
Jlariou Island to Crozet 
Islands— Off Crozet Islands. Off Kerguelen Island. Off Heard Island. 
