i8 9 2.] 
465 
[De Geer. 
graphical features are sometimes at a distance terrace-like, but 
no true marine terraces either cut or built could be observed. 
So complete indeed is the preservation of the topography from 
marine erosion that Professor Shaler, who has thoroughly inves- 
tigated the island, has come to the conclusion, that if this tract 
has been submerged it must have been uplifted quite suddenly. 
But it seems unnecessary to make use of this explanation ; for 
while I have not seen many of the kames in this locality, 1 
should imagine that it would be easier to account for their ridge- 
like, winding shape, if we assume that they, like the ordinary 
osars, originated between walls of land-ice or possibly in some 
cases of river-ice and snow. If they had been deposited in the 
sea it would appear that the shape should have been more like 
a delta or a built terrace. As to the submerged valleys on the 
southern side of the island, these might also be most readily ex- 
plained by supra-marine erosion of glacial rivers ; for if they 
were formed below the sea-level, by bottom-currents, coining 
from the mouths of sub-glacial rivers, we might expect them to 
be broadest and deepest at their beginning, whereas on the con- 
trary they regularly increase in size as they depart from the 
terminal moraine. Moreover it seems scarcely probable that 
such currents could have kept together for more than live miles, 
and it is specially difficult to account for the fact that all the 
small tributaries come in at great angles. Furthermore, I may 
remark that all the glacial rivers that I have observed in Spitz- 
bergen pour out their muddy waters as a thin layer on the sur- 
face of the sea, even in the interior of the fiords, where the sea- 
water is, probably much less salt than on the open glacial coast of 
Martha’s Vineyard. 
Both at Vineyard Haven, Martha’s Vineyard, and at Wood’s 
Holl on the mainland the actual shore-terrace is very w^ell marked 
and the beach, is covered with numerous residuary boulders, while 
the cliffs often consist of unwashed till, which has evidently 
never been submerged. 
Boston. 
In the neighborhood of Boston I made excursions in company 
with Mr. Warren Upham and examined especially the surfaces of 
several drumlins without being able to see any traces of marine 
proceedings b. s. N. h, VOL. xxv. 30 Sept. 1892. 
