395 
bergen during the Norwegian North-Atlantic Expedition 
1876—78, and that shells as Portlandia arctica, Portilandia inter- 
media, Cardium groenlandicum, Cardium ciliatum, Astarte borealis, 
Åstarte banksi, Tellina calcarea, Saæicava arctica, and Cyrtodaria 
siliqua have been dredged at depths from ca. 500 to ea. 1350 fms. 
between Jan Mayen and Iceland during the Danish Ingolf- 
Expedition 1895—96. Recently Mr. R. Higg, fil. cand., has 
kindly informed me that the Swedish North Polar Expedition 
of 1900 also dredged several shallow-water shells, but not many 
specimens, at great depths between Jan Mayen and Spitzbergen. 
While Friele (1. c. 1879) explains this phenomenon by the 
theory of transportation by floating ice, Professor W. Brøgger 
(1: c. 1900—1901), and A. S. Jensen (1. e. 1900), have on the 
contrary urged that a sinking of the sea-bed more probably has 
taken place than a transportation of the shells, and Professor Fr. 
Nansen has arrived at the same conclusion "). 
If the phenomenon be accounted for by the hypothesis of a 
sinking of the seabed, Prof. Brøgger has concluded that the sea- 
bottom of the North Polar Basin, during the time of the greatest 
ice-sheet of Europe,- must have been uplifted to a height surpassing 
by 2600 metres that of the present time. 
Let us, however, consider the reasons which the named authors 
urge against the explanation of the phenomenon by the theory of 
transportation by floating ice. The reasons are as follows: 
1) Among the dead shells which occur at considerable depths in 
the North Polar Basin are those of Portlandia intermedia. (Dead 
shells are found at depths of 658, 1003 and 1309 fms.). The 
vertical distribution of this species in the North Polar Basin 
reach from 40 to ca. 500 fms. - As it does not occur at lesser 
depths than at 40 fms., it is outside the reach of the ice. 
A.S.Jensen writes about this form”): ,,Af denne lille Musling 
1) Letter to Brøgger. a iron p. 94—96. 
7”) Å, S. Jensen, |. c. i PD, 282. 
