•218 
THE VOYAGE OF H.M.S. CHALLENGER. 
As has been already stated, the residue of a Globigerina Ooze is in all essential 
particulars the same as a Red Clay from the adjacent regions of the ocean’s bed. The 
trawl and dredge brought up from Globigerina Oozes large pumice stones in 12 instances, 
manganese nodules 6 times, sharks’ teeth and earbones of Cetaceans 4 times, and more 
rarely phosphatic concretions, pebbles, and aggregations of the deposit. Numerous 
animals belonging to the fishes and all the invertebrate marine groups have been dredged 
and trawled from the Globigerina Oozes, life being apparently much more abundant on 
these than on the Red Clay and Radiolarian deposits. 
The following shows the average composition of the 118 Challenger samples of 
Globiijerina Ooze : — 
O 
Carbonate of lime, 
Pelagic Foraminifera, 
- Bottom-living Foraminifera, 
Other organisms. 
53-10 
2-13 
9-24 
64-47 
Residue, 
Siliceous organisms, 
- Minerals, . 
Fine Washings, 
1-64 
3-33 
30-56 
35-53 
100-00 
The analyses of a large number of Globigerina Oozes, presented in the table on the next 
page, support the above views as to the composition of the deposit. 
The important role [)layed by the remains of calcareous organisms in these deposits 
is indicated by the high percentage of the portion soluble in hydrochloric acid, and 
•especially by that in the column CaCOg; although the carbonate of calcium varies greatly 
in the different specimens of Globigerina Ooze, the annexed analyses show that it usually 
forms more than one-half of the whole deposit, and often rises to a much higher limit. 
'Fhis high percentage of carbonate of lime might be said to efface in a manner the 
.small quantity of other substances mixed with the calcareous organisms. However, the 
columns showing the lo.ss on ignition, silica, alumina, and iron, indicate small quantities 
•if argillaceous and ferruginous matters, associated with the remains of siliceous organisms. 
It may be observe<l that the loss on ignition docs not augment with the proportion of 
carbonate of lime, but rather with an incrciise of silica, alumina, and ferric oxide, so that 
the larger part of the loss on ignition is rather to be referred to the water combined with 
these substances than to organic matters. The sulphate and pho.sphate of calcium in 
these analyses are to be attributed, as in the case of the Red Clay, to the presence of 
sea- water salts and of phosphatic organic remains. ’I'lierc does not seem to be any 
relation between the ])ercentages of carbonate of lime and carbonate of magnesia as 
might l>e exj*ected if the carbonate of magnesia played a role in the original constitution 
