416 WARREN UPHAM, ESQ., M.A., F.G.S.A., ON 
areas as indicated, among other things, by the sub-oceanic river- 
valleys. 
With respect to the astronomical explanation of a presumed 
glacial recession to which reference is made in this paper, I may 
remark that the Southern Hemisphere is towards the sun, when 
the earth is in perihelion, and yet the climate of the Antarctic is 
quite as rigorous as that of the Arctic Regions. There is reason 
therefore to think that if the northern summers were brought 
into perihelion the climate of the Northern Hemisphere would be 
scarcely, if at all, affected. 
Neither can I agree with the attribution of depression of land 
areas to the weight of accumulated ice, referred to as ‘“‘ burdened 
land,” since I ascribe auy such depression to contraction of vast 
thicknesses of terrestrial matter consequent upon a lowering of 
temperature, and elevation to expansion of similar enormous 
masses from a@ rise in temperature. 
The paleontological evidence certainly seems to me to be 
strongly against the pre-glacial age of the Somme gravels. 
In addition to Lyell’s statement of it I may mention that that 
interesting little fresh-water Lamellibranch the Cyrena fluminalis, 
is to be found in abundance as a fossil in the brick-earths of the 
Lower Thames Valley, as at Grays, Crayford, and Ilford, and 
that though not now living in European rivers, but abundant 
in the waters of the Nile. I have also found it in the gravels of 
the Orange River of South Africa. 
The CuHatrMan.—I would just say that from my own poini of 
view there is one important matter in this paper, and that is, the 
date of the ending of the Ice age, which the author sets down at 
about 5,000 years ago. 
Now in Babylonia, civilization, such as it was, extends back 
certainly 5,000 years; and if in that country the estimates of 
the American excavators of Niffer may be accepted, it ought to 
go back 10,000 years from now. 
That means, I suppose (I am speaking under correction of 
course), that the temperature of Babylonia must have been in 
those times, 5,000 to 10,000 years ago (and the farther back you go 
the more so), greatly affected by the presence of ice in other parts 
of the world, and that is a matter of some interest to people who 
consider the civilization and state of the country in ancient times 
and especially in connection with the products. The tempera- 
