J. Murray on Sea-bottom Deposits. 259 
along the east coast of South America, from Cape San Roque 
to Bahia, differed from the deposits found along the shores of 
other continents and large islands in being of a red color. There 
can be little doubt but that this red color is due to the presence 
of the ochreous matter carried into the Atlantic by the South 
American rivers. here are reasons for thinking that the red 
color of some of the deep-sea clays in this region of the Atlantic 
may have a like origin. 
he soundings near the shore and in shallow water have a 
deeper red color and contain larger mineral particles and fewer 
organic remains than those farther from land and in deeper 
water. The mineral particles are chiefly quartz and mica. 
In all these soundings there are many pelagic and other Fo- 
raminifera, Heteropod, Pteropod, larval Gasteropod, and Lamelli- 
branch shells, Coccoliths, and Rhabdoliths. Siliceous organic 
remains, as of Diatoms and Radiolaria, are almost quite absent 
in these bottoms. In some of the shallower depths a few red- 
colored casts of Foraminifera were observed; but these were 
tare, rough, and more or less imperfect. 
he following are the depths of the soundings along this 
coast :— 
fms. fms. fms. fms. fms. 
1375 1650 32 1600 1015 
500 675 400 1200 1275 
2050 120 1715 700 2150 
e 
those at St. Paul’s Rocks, and probably serpentine. One or two 
‘aminifera were noticed about Bermuda. 
At the Virgin Islands, at Tongatabu, at Fiji Islands, at Cape 
ork, Admiralty Islands, Honolulu, and Tabiti we also met 
with coral-muds. Except at Cape York, these muds appeared 
