516 
Proceedings of the Royal Society 
Geographical and Bathymetrical Distribution. —in the preceding 
pages we have confined our remarks essentially to the lithological 
nature of the deep-sea deposits, including in this term the dead 
shells and skeletons of organisms. From this point of view it has 
been possible to define the sediments and to give them distinctive 
names. We now proceed to consider their geographical and bathy- 
metrical distribution, and the relations which exist between the 
mineralogical and organic composition, and the different areas of 
the ocean in which they are formed. 
A cursory glance at the geographical distribution shows that the 
deposits which we have designated muds and sands are situated 
at various depths at no great distance from the land, while the 
ORGANIC OOZES and RED CLAYS occupy the abysmal regions of the 
ocean basins far from land. Leaving out of view the coral and 
volcanic muds and sands which are found principally around oceanic 
islands, we notice that our blue muds, green muds and sands, red 
muds, together with all the coast and shore formations, are situated 
along the margins of the continents and in enclosed and partially 
enclosed seas. The chief characteristic of these deposits is the 
presence in them of continental debris. The blue muds are found 
in all the deeper parts of the regions just indicated, and especially 
near the embouchures of rivers. Bed muds do not differ much from 
blue muds except in colour, due to the presence of ferruginous 
matter in great abundance, and we find them under the same condi- 
tions as the blue muds. The green muds and sands occupy, as a rule, 
portions of the coast where detrital matter from rivers is not 
apparently accumulating at a rapid rate, viz., on such places as the 
Agulhas Bank, off the east coast of Australia, off the coast of Spain, 
and at various points along the coast of America. 
Let us east a glance at the region occupied by terrigenous 
deposits, in which we include all truly littoral formations. This 
region extends from high-water mark down, it may be, to a depth 
of over four miles, and in a horizontal direction from 60 to per- 
haps 300 miles seawards, and includes, in the view we take, all 
inland seas, such as the North Sea, Norwegian Sea, Mediterranean 
Sea, Bed Sea, China Sea, Japan Sea, Carribean Sea, and many others. 
It is the region of change and of variety with respect to light, 
temperature, motion, and biological conditions. In the surface 
