404 
and 100 fms., off Jan. Mayen, Spitzbergen and Bear Island. The 
objection which can be put forth against this, starting from the 
sinking hypothesis, is that these shells in the course of time may 
have been covered with so considerable masses of bottom deposits 
that the trawl has only penetrated very little into the old sea 
bottom; this objéction, however, does not wholly, I believe, inva- 
lidate the argument which I have here set forth. 
On shallow-water shells at considerable depths 
on the banks and slopes of the oceans. 
As the mentioned occurrence of dead shallow-water shells at 
great depths in the Arctic sea has been interpreted as a proof of 
a former sinking of the sea-bed so also the presence of dead littoral 
shells at relatively great depths off the Norwegian coasts and on 
the banks and slopes in the East-Atlantic has been understood in 
the same way to indicate a sinking of the sea-bed in these parts 
of the sea. Several authors have maintained this view with respect 
to lesser parts of the sea-bed, and recently Professor Broågger in 
his great work on the ,,Nivåforandringer i Kristianiagebetet" has 
taken these shells as a proof of a sinking of what he calls the 
»Continental platform" of Europe. 
In a previous paper (1. c. 1901) I have emphasized that it is 
a general rule that the dead shells are only partly deposited inside 
the vertical range of the molluse-species to which they belong. 
In many different ways, by means of currents, tidal action, the 
transporting activity of the waves, organisms, etc., a great trans- 
portation of shells takes place, especially at steep coasts. The 
question is now when we find shells deposited outside the verti- 
cal range of the corresponding species whether they have been 
derived from another place or not. In the following is represented 
a view of.the sinking hypotheses which hitherto have been set 
forth by Jeffreys, G. O. Sars, J. Spotswood Green and Å. S. 
Jensen, with respect to banks and slopes at the Norwegian coasts 
