60 trotuso Museums Àarsheftor 28. — l905. 



(3). The hard bottom, 



id II depth of 20 to 50 fathom« or more, often cousiöts of 

 stones and stonalgaes with multitudes of beautiful, large, 

 reddish coloured mussels [Pecten islandiciis), which are 

 used for bait. Besides these are numbers of other shells 

 and crustaceans of various kinds. On the solid rocky- 

 slopes at the sides of the fjords corals, sponges ascidians 

 and bryozoa grow. 



(4). The mud bottom. 



In the fjords from the innermost part of the Bals- 

 fj(jrd to the open sea there are several deep channels and 

 Ixisins'^'). Between these depressions shallow ridges or bar- 

 riers cross the fjords, which greatly influence the com- 

 pression and temperature of the water in the deep cavi- 

 ties inside. 1 thus found the temperature at the depth of 

 70 fathoms near Tennæs in the Balsfjord, in the 15th of 

 August 1903, to be 2.9"^ C, Avhile the temperature at sea 

 at a depth of 160 fathoms, on the 6th of September 1902, 

 was ô*' C. The fauna on the clay bottom in the exterior 

 parts of the fjords is intermixed with southern forms 

 such as Ave find on the shores of the North Sea, Avhile the 

 fauna in the Balsfjord is arctic. 



The large deep water shrimps [Pandalus borealis) oc- 

 cur in great abundance in the innermost part of the Bals- 

 fjord at depths of between 60 and 70 fathoms, where 1 

 made several hauls with a little shrimptrawl. 10 hauls, 

 each in a space of half an hour or an haur, yielded in 

 all 30 litres of shrimps. 



On the accompanying tables will be found the mea- 

 surements of various animals. The measurements give 

 curves, each representing an annual class. 



♦) See the accompanying cliart, where the depths of tho basins 

 and ridges arc indicated in fathoms. 



Trykt 14. Noybr, 00. 



