The fishes of the Danmark Expedition. 639 



outer and central parts. Apart from a small, isolated part off 

 Nordre Havnenæs, we only find a depth of 30 m in the middle of 

 the entrance to the harbour, and the curves of this and greater 

 depths (40, 50, 60 m) lie almost concentrically there. 



The temperature and salinity of the sea-water are distributed 

 in the main as follows. The Greenland Sea can be divided into 

 three regions: 1) the Spitzbergen plateau, 2) the deep central region 

 and 3) the East Greenland plateau. Only the last concerns us here. 

 It is entirely filled by the East Greenland Polar Current, with the 

 result, that the temperature and salinity of the water are low. In 

 the surface-water the salinity (at least in summer, when the snow 

 and ice are melting) is below 32 °/oo, this isohaline following fairly 

 exactly the 500 m curve (in deeper water the salinity at the surface 

 is over 32 ^/oo; it is highest where there is no ice). The temperature 

 is in general higher than — 1°. The surface-water has an even 

 thickness of ca. 20 m. Below this and down to ca. 150 m the water 

 has a salinity of 32—34 ^/oo and a temperature of — 1-8°. Lower 

 down (to ca. 300 m) the salinity is 34—35 °/oo and the temperature 

 is from negative to a little over 0°. Lastly, in the lowermost ca. 

 200 m there is water with a salinity of over 35 °/oo and a tempera- 

 ture of up to +1°; it is presumably an extension from the bottom- 

 water in the great depths outside. The conditions described are 

 found in the outer part of the coastal plateau; but in corresponding 

 depths nearer the coast (0, 50, 100, 200, 300, 400 and 500 m) we 

 find corresponding temperatures and salinities. In the fjords round 

 about Danmarks Havn, where the depths are as described above 

 the surface-water is more or less mixed with fresh-water ac- 

 cording to the time of year. In the fjords where there is no 

 submarine ridge ("Lillebælt" and "Storebælt"), the salter, deeper 

 water is able to penetrate inwards, preserving approximately the 

 same salinity and temperature as outside; but where there are ridges, 

 only the surface and upper layers can pass and in the deeper holes 

 referred to above (e. g. in Stormbugt) the circulation in the deepest 

 layers (over ca. 200 m) is very slow, and both the salinity and 

 temperature are therefore lower than at the corresponding depth in 

 "Lillebælt" and "Storebælt" as well as in the sea outside. — 



In regard to the nature of the bottom-soil we may again take 

 Danmarks Havn as type. We can distinguish in general between 

 two main kinds of bottom-soil; namely, soft and hard. By the 

 former I understand clay or mud more or less mixed with sand; 

 often we also find a number of loose stones in it. When these are 

 specially numerous or large, however, the soil changes to hard, 

 i. e. it consists of numerous, rounded stones with shells; or the rocky 



