J. Murray on Sea-botiom Deposits. 255 
Art. XXXII.—On the Sea-bottom Deposits observed during the 
Cruise of the Challenger in a report to Prof. Wyville Thomson ; 
by Jonn Murray, Hsq., naturalist of the expedition.* 
Tux kinds of deposits obtained in soundings by the Challen- 
ger, may for the present be classed under the following heads :— 
. Shore-deposits. 
(2) Blue and green muds.—Met with near the shores of most 
of the great continents and islands. 
(}) Gray muds and sands.—Met with chiefly near oceanic 
islands of volcanic origin. 
(c) Red mud.—Met with on the eastern coast of South 
America. 
(d) Coral-mud.—Met with near coral reefs. 
2. igerina-ooz.—An abundant oceanic deposit not met with 
south of latitude 50° S. 
8, Radiolarian ooze.—An oceanic deposit met with only in the 
_ Western and Middle Pacific. 
4. Diatomaceous ooze.—An oceanic deposit met with only south 
rel arrest, a Globigerina, Radiolarian, or Diatom ooze, or red 
ay clay. 
metimes it has been doubtful whether a specimen should 
be placed under one of the above heads or another, on account 
of the nearly equal ratio of constituents, or where one deposit 
overlies another of a different kind. In these cases the spect- 
men has been placed under that head with which, on a general 
View, it has seemed to have most in common, or to which the 
Surface-layer belonged, and a detailed description has been 
added in the list, , 
A sixth kind of deposit or formation might have been added, 
” embrace those bottoms in which a great quantity of the 
Peroxide of manganese occurs. ‘This substance, 1n the form of 
* From the 5 
remarks of the Royal Society, vol. xxiv, 
the here cited are preceded in the oath detailed descriptions of each of 
from i e course of the expedition. These notes and conclusions are 
o 
4 preliminary report, which is soon to be followed, now that the expedition 
‘as returned, with a fuller statement.—Ebs. 
