KEPOET ON THE DEEP-SEA DEPOSITS. 
173 
deeper hauls with the surface tow-nets. Some of the spines on the Glohigerinx were 
very long and delicate, being eleven times the diameter of the shell. 
Sulu Sea. — The two soundings in the Sulu Sea at 2550 and 2225 fathoms (see Chart 
31 and Diagram 14) were Blue Muds, containing in the former a trace, in the latter 15 
per cent., of carbonate of lime, derived principally from pelagic Foraminifera. The 
greater part of the deposits is made up of amorphous and clayey matter. At 2225 
fathoms there were two layers, upper red, lower blue ; little difference could be detected 
between them except that of colour. There was evidence of the same arrangement in 
layers in the deposit in 2550 fathoms. 
Passages among and hetiveen the Philif'pine Islands. — Several soundings were taken 
in these passages in October and November 1874 and January 1875 (see Chart 31 and 
Diagram 14). At 700 and 705 fathoms the deposit was a Blue Mud, with 3 to 11 per 
cent, of carbonate of lime. The mineral particles were larger and more numerous in the 
latter than in the former. The deposit from 375 fathoms was a Green Mud containing 
36 per cent, of carbonate of lime largely made up of the shells of pelagic Foraminifera ; 
glauconite, numerous casts, and many oval arenaceous bodies, believed to be the excreta 
of Echinoderms, were observed. The minerals were few and small, and embraced 
felspars, augite, hornblende, magnetite, and altered volcanic rock fragments. At 100 
and 115 fathoms the bottom consisted of Green Mud with from 50 to 56 per cent, of 
carbonate of lime, derived from shells of pelagic Foraminifera, fragments of Gasteropods, 
Lamellibranchs, Echinoderms, and Polyzoa. The mineral particles were of a similar 
nature to those at 705 fathoms with the exception of glauconite, which is absent in the 
greater depth but present in considerable quantities in these Green Muds. These minercal 
particles make up from 30 to 40 per cent. After treatment with dilute acids a great 
many pale and dark green casts of the organisms were observed. These with Sponge 
spicules, Radiolaria, and arenaceous Foraminifera were estimated to form 3 to 4 per 
cent. The deposit in 95 fathoms was a Blue Mud containing about 36 per cent, of 
carbonate of lime, which consisted of a large number of pelagic and other Foramini- 
fera, fragments of Echinoderms, Molluscs, and Polyzoa. This and the following station 
are within an area known as the Euplectella ground, where the greatest number 
of these Sponges was obtained. The siliceous organisms formed fully 10 per cent. 
Glauconite is found among the minerals, while abundant casts of the organisms remain 
after treatment with dilute acid. This seems to be a Green Mud in process of formation 
and resembles that obtained off the coast of Australia, near Sydney. 
China Sea. — In the voyage to Hong Kong and back two soundings were obtained 
in 2100 and 1050 fathoms (see Chart 31 and Diagram 14). The deposits were Blue 
Muds, containing in the former a trace, in the latter 22 per cent., of carbonate of lime 
chiefly composed of pelagic organisms. The mineral particles made up from 5 to 10 per 
cent., consisting of c[uartz, felspars, hornblende, augite, magnetite, and volcanic glass; 
