1898 - 99 .] Soundings obtained by s.s. ‘ Britannia .’ 
427 
Residue (97%). 
Minerals (1%), small particles of glass and mica. 
Siliceous Organisms (1%), Sponge spicules. 
Fine Washings (95%), amorphous clayey matter, with very 
minute mineral particles. 
S.S. ‘Britannia,’ No. 182, 2nd December 1897. Lat. 32° 14' 26" N., 
long. 64° 39' 45" W., 1000 fathoms. 
PTEROPOD OOZE, pure white when dry. 
Calcium Carbonate [79‘59%], pelagic Foraminifera, Ptero- 
pods, Ostracodes, Alcyonarian spicules, Echini spines, Fishes 
teeth, a few bottom-living Foraminifera, Tunicate spicules, 
coccoliths, rhabdoliths. Some of the shells are discoloured 
black by manganese. 
Residue (20-41%). 
Minerals (1%), small glassy and green particles. 
Siliceous Organisms (3%), Sponge spicules, Radiolaria, aren- 
aceous Foraminifera. 
Fine Washings (16*41%), amorphous clayey matter. 
DESCRIPTION OF THE MAP. 
The map accompanying this paper represents the present state 
of our knowledge concerning the marine deposits in the south- 
western portion of the North Atlantic. The various kinds of 
deposits are shown in different colours, but it must he remembered 
that each variety of deposit slowly passes into adjacent varieties 
without any marked line of separation such as the colours on the 
map tend to suggest. It is often difficult to say whether a given 
sample should be called a Red Clay or a Globigerina Ooze, a 
Pteropod Ooze or a Coral Mud, a Blue Mud, a Green Mud, or a 
Y olcanic Mud, although typical samples of each of these varieties 
are quite distinct from one another. 
The Bermudas, which are situated towards the north- east corner 
of the map, consist of a number of coral islets which crown the 
