Freshwater Life in Nortii-East Greenland. 325 



2. 25-50 M. I 



3. 50-70 - } No animal life. The copepods were thus found in — 25 M. 



4. 70-85 - 



On the other hand, Sælsøen may become quite free of ice as 

 we found in August 1906 (icebergs from the inland ice were even 

 floating about). But only a small part of it (the lower, eastern end) 

 was ice-free in the unfavourable summer of 1907 ; on the rest of the 

 lake lay the unbroken ice of the previous year (only melted along 

 the bank). In the summer of 1908 we departed before the ice had 

 completely melted (middle of July), but it was evident from the 

 nature of the ice (very "porous"; much ice melted at the eastern 

 end and along the banks), that at least most of the lake would 

 become free of ice. On ^^5 08 the thickness of the ice was mea- 

 sured at one place (over 2 meters thick) and on ^^/5 08 at another 

 place (1.76 meters thick). At the end of June there is open water 

 along the bank (just as in the smaller lakes to be mentioned later), 

 but out in the centre the ice is still meter-thick and quite free of 

 snow owing to the strong wind blowing down over it. The depth 

 at the eastern end of the lake was but small (cf. the nature of the 

 banks here as already mentioned), but increases gradually as we go 

 further west; in the centre of the lake here the depth is 69 meters 

 (bottom fine gray clay). The depth still increases towards the west; 

 about halfwa}' along the lake we found 117 meters (bottom as 

 before). The hydrographical conditions in the lake are very inter- 

 esting (cf. the two following tables), as the w a t e r at a depth of 

 55 — 5 6 meters changes over from fresh to brackish and 

 further to strongly saline, and at the same time the tem- 

 perature rises; in other words, the surface water and the bottom 

 water are different. Regarding the nature of the currents between 

 these two layers and in the Lake as a whole, as also whether the 

 temperatures obtained hold good for other seasons of the year, 

 nothing is known. On the same occasion, ^^/5 08, I took three ver- 

 tical hauls with the above-mentioned plankton net. (Depth and 

 bottom as ^^/r. 1908.) 



No animal life. 



1. 115—85 M. I 



2. 85—55 - j 



3. 55 — - Here two pale-white copepods (Diaptoimis miimtiis 



Lilljb.) one of them with egg-sac. P. S. At the 

 same spot and depth I caught, a month later 

 (^^/c 1908), some other, pale-white copepods {Lim- 

 nocalamis macrnnis, G. O. Sars). 



