‘26 
THE VOYAGE OF H.M.S. CHALLENGER. 
To sum up, tlieii, with rcfereuce to any one of the examples taken from the Tables 
in Chapter II., it will be observed that the number of the station is first given, then 
follow the date, the position, the depth from which the specimen was obtained, and the 
temperature of the water at the surface and bottom of the sea, when these are known. 
The name given to the deposit is then stated, with the general physical characters, and 
the colour of the residue after tlie removal of the carbonate of calcium is also noted in the 
same column. The footnotes in the tables give the numbers of the analyses of substances 
from each station ; these analyses will be found tabulated in the subsequent chapters. 
References to the specimens figured in the plates are also given in the footnotes. 
Under the heading Carbonate of Calcium there are three columns, the first giving 
the percentage of this substance in the whole deposit, the figures having been obtained by 
quantitative analysis. In the second column the general designations of the Foraminifera 
which secrete lime are given in two groups, the first including those which live on the surface 
of the ocean and whose dead shells accumulate at the bottom of the sea and form by far 
the largest part of the carbonate of lime in oceanic deposits; the second group includes 
those lime-secreting Foraminifera that pass the whole of their lives at the bottom of 
the sea. Before each of these groups will be found numbers within brackets, giving an 
estimated percentage of the part each j)lays in making up the whole deposit. In the third 
column wll be found an indication of the remains of other lime-secreting organisms 
obseiA’cd in the deposit, such as pelagic and other Molluscs, otoliths of fish, fragments of 
Echinoderms, calcareous spicules of Alcyonaria, Corals, Ostracodes, calcareous Algae, &c., 
and the number before this group gives the estimated amount of these in the whole 
deposit. Except when the shells of pelagic Molluscs are present, this group does not 
make up a large part of any deposit in water over 200 fathoms ^ in depth. 
Under tlie heading Residue the first column gives the percentage of the residue in 
tlic whole deposit, the figures here being obtained by subtracting the weight of carbonate 
of calcium found by analysis in 100 parts of the deposit. In the following column is given 
the general designation of the siliceous organisms or their fragments, and the estimated 
percentage of these in the whole deposit. Under this head are included those Foramini- 
fera which build their tests by cementing together the mineral particles of the deposit, 
as well as those internal casts of calcareous organisms which have usually more or less of 
a glauconitic character. In the next column is given the mineral and crystalline 
fragments, with their mean diameter in millimetres, and the estimated part these as a 
whole take in the formation of the deposit. As a rule, the order in which the various 
8fK!cies of minerals arc stated gives an index to their abundance in the deposit, the most 
numerous l>eing stated first, the least numerous last. In the fourth column, under this 
heading, will be found a statement as to the bulk and eharacter of the fine washings of 
the residue. The constitution of these is very complex, but is fundamentally of an 
' 3G6 inctrca 
