I. Introduction. 



ihe samples of the sea-floor collected by the Danish 

 expedition to East Greenland, are in many respects of 

 very great interest. The physical conditions which generally 

 determine the nature of sea-floor deposits are here most char- 

 acteristic and peculiar, in comparison with those of all other 

 localities hitherto examined. The coast is rocky with great 

 deep bays into which large glaciers flow; outside this coast the 

 sea is generally covered by immense masses of ice, consisting 

 of an irregular mixture of sea-ice, coast-ice, and glacier-ice, 

 drifted on by a constant current along the shore; these peculiar 

 conditions combine to produce in the samples an appearance 

 widely different from that of all deposits hitherto known. 



The most important characteristics of such deposits, and 

 those which together determine their nature are essentially of 

 three different kinds, viz. 1) The variation in size of the grains 

 found in the samples, 2) The mineralogicai constitution of the 

 inorganic material, and 3) The number and nature of organisms 

 found in the samples. A few other characters may be named 

 which are not absolutely dependent on any of the above men- 

 tioned ones, but which are, nevertheless, of the greatest im- 

 portance in determining the general nature of the deposit, viz. 

 the colour and the greater or less degree of coherence in the 



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