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154 Results of Microscopic Examinations of Soundings. 
n stating the results obtained from the specimens, a will 
be referred to by the numbers as above given. Numbers | to 4 
inclusive are composed of fine siliceous sands, the grains of 
which are mostly of small size with sharp angles. The organ 
contents are not abundant; of the calcareous Polythalamia there 
5 is 
ery quartz, with some feldspar, &c. It is much the’ 
ne 
an 
Rinisest of all the specimens exami 
Some of the quartz grains are rou unded by attrition, while a 
large portion are quite shat and unabraded. Among the or- © 
oggacee were noticed with some ie 
ganic contents a very few Po 
Diatomaceze and sponge spicules 
. 6 is a fine calcareous mud which effervesces briskly with : 
sida and yields by this treatment a large residue of siliceous 
Vos, 7 to 21 inclusive are fine aisirsoee muds which effer- 
vesce briskly with acids, and abound in the calcareous Polythal- 
ama and particularly in species of Globigerina. They also con- 
tain numerous and very Raub ts species of the siliceous Poly- 
cistins, Diatoms, and Spon he mineral residue from 
ot 
acids is usually quite small in relative amount, and consists of ae 
minute sharp-angled grains among which quartz el i 
Nos. 8 to 21 inclusive contain, in addition to what is above 
mentioned, what appear to be well characterized ‘woleardl + ashes, 
in the shape of minute fragments of pumice and obsidian, crys 
tals of various minerals single and in groups, with vitreous pro 
— penetrated with crystals. These substances generall y form 
a small portion of the residue left by the acids, and may 
a more readily detected when this residue is in water than 
Xo — eral in balsam. They are particularly recognizable in : | 
mR a ae and some very fine and perfect specimens of Coscinodiscus 
uh pets oe Acai Yon and @. chomnhgy paige > in these s ens. 
CO. fureili 
rinsings from the coarse gravel of No.5 gave a few Polythalamia, and 
§ They are scarcely less so in No. 15 to 18. In the No. 8 and No. 21 
specimens No. 
the voleanic products were found, but only in in small proportion and after cafe 
Eee 
