172 
THE VOYAGE OF H.M.S. CHALLENGER. 
Pelagic Foramiiiifera aud Coccolitlis were abundant. The mineral particles consisted of 
quartz, mica, volcanic glass, magnetite, felspar, pumice, and fragments of rocks. 
The trawl brought up a considerable quantity of mud, which, with the exception of 
a few lumps, all belonged to the brownish surface layer. Mixed up with the mud were 
many large fragments of pumice, pieces of wood, leaves, and fragments of cocoa-nuts and 
other fruits. As was usually the case when the trawl brought up mud from the imme- 
diate surfoce layer, there was a large quantity of the weed-like branching Ehizopod 
described by jMr. II. B. Brady under the name of Rhizammina algseformis, and in 
addition many deep-sea animals. 
Off Amboina in 15 to 20 fathoms the deposit consisted chiefly of Gasteropod and 
Lamellibranch fragments, while Ileterostegina corngdanata, var. granulosa, was largely 
represented. In addition there were mineral fragments consisting of quartz, felspars, 
aud particles of volcanic rocks. 
Molucca Passage. — After leaving Amboina two soundings were obtained in the 
^lolucca Passage, in 825 and 1200 fathoms (see Chart 31 and Diagram 14). The 
souuilings were not successful, but from the latter depth sufficient material was obtained 
to indicate that the deposit was a Blue Mud. At 825 fathoms the trawl brought up large 
irregular fragments of a honeycombed conglomerate, overgrown with Serpula, Polyzoa, 
and Sponges. The largest fragment measured 12 by 8 inches (30 by 20 centimetres), 
aud was not unlike that obtained at Station 192a, but was much harder and the 
organisms were less apparent. Thin sections examined by the microscope showed that 
the conglomerate was composed of Foraminifera and calcareous Algae cemented together 
into a hard crystalline limestone, which on analysis yielded 94 per cent, of carbonate of 
lime. This rock, unlike that from Station 192a, would seem to have been formed in com- 
paratively shallow water near land. A few Coral fragments were also brought up in the 
trawl. 
Celebes Sea. — Four soundings were taken in the Celebes Sea at 2150, 2600, 250, 
and 2050 fathoms (sec Chart 31 and Diagram 14). The deposit at 2150 and 2600 
fathoms wa.s a Volcanic Mud, the great bulk of which was composed of broken-down frag- 
ments of pumice aud clayey matter, while at 2050 fathoms, near the coast of Mindanao 
Island, it was a Blue ]\Iud with a considerable proportion of quartz grains among the 
mineral jjarticles. There were only slight traces of carbonate of lime, the highest per- 
centage (P75) being found in 2050 fathoms; this was derived from a few fragments 
of Pteropods and pelagic Foraminifera shells. In each case there were two layers, the 
upper layer oozy and of a reddish colour, the lower compact aud of a blue colour. At 
250 fathoms the deposit was a Green j\Iud ; only a small quantity was obtained, in- 
sufficient for detailed examination. The trawling in 2150 fathoms (Station 198) yielded 
several fragments of volcanic rock, some palm fruits, and pieces of wood and bark. 
( rlobigerina, Pulvimilina, Orhulina, aud Pullenia shells were very numerous in the 
