182 
THE VOYAGE OF H.M.S. CHALLENGER. 
maugancse. The pelagic Foramiuifera in the deposit were chiefly shells of Glohigerina 
with a few of Orhulina and Pulvinulina, and all these were very small and dwarfed, 
in this respect agreeing with those taken on the surface by means of the tow-nets. 
The trawl again brought up a large number of animals and some manganese nodules. 
Some of these latter appeared to have been fragments torn from larger masses, and some 
had nuclei which seemed originally to have been portions of the ooze itself. This associa- 
tion of manganese nodules with altered volcanic fragments in a Globigerina Ooze was 
frequently observed during the Expedition. 
The deposit in 1325 fathoms was a Blue Mud containing 26 per cent, of carbonate of 
lime, made up of pelagic and other Foraminifera, fragments of Polyzoa, Echini spines, 
Ostracode shells, and fragments of other calcareous organisms. The mineral particles 
consisted chiefly of quartz and fragments of rocks and minerals derived from the 
continent. 
Gulf of Penas to Sandy Point through Magellan Strait. — The deposits in the 
Messier and Sarmiento Channels and Magellan Strait were in all cases Blue Muds con- 
taining generally very little carbonate of lime, and consisting mostly of debris from the 
neighbouring mountains. At Stations 308 and 311 there was 29 and 34 per cent, of 
carbonate of lime respectively. These deposits were forming in more or less open water, 
or in water afiected by the ocean ; the former was situated at the junction of Trinidad 
Channel vith Conception Channel, the latter in the open water of Sea Beach (see Chart 
41 ). Pelagic Foraminifera were only represented by a few stray specimens of Glohigerina, 
and on the surface only a few of these shells were noticed, the deposits and surface 
fjatherinnrs in these enclosed channels thus being in marked contrast to what are found 
in the open sea, at some distance from land. The mineral fragments proper made up 
from 1 to 75 per cent, of the muds, and consisted of quartz, felspars, hornblende, mica, 
pumice, magnetite, and lapilli. Casts of organisms were observed in one or two cases. 
In addition to the Challenger collections, the deposits from many lines of soundings, 
carried out by other ships, have passed through our hands ; several thousand samples of 
deposits from nearly all regions of the great ocean basins and from many enclosed seas 
have thus been examined in the same way as the Challenger specimens. The general 
results are exhibited on Chart 1, which will be specially referred to when dealing with the 
geographical and bathymetrical distribution of deposits in a subsequent chapter. How- 
ever, it may here be pointed out that the examination of these additional specimens 
confirm all the general conclusions indicated in the foregoing remarks on the Challenger 
sections across ocean basins and enclosed seas. They indicate a greater abundance of the 
remains of carbonate of lime organisms in the deposits from tropical regions, — those of 
pelagic surface-living organisms abounding in the deposits from deep water removed from 
the shores of continents and islands, and those of bottom-living or attached organisms 
