48 0. Nordgaard. [No. 8 



The mud from the bottom of the Lyse Fiord did not smell of 

 sulphuretted hydrogen, as did that of the Mo Fiord. 



There were many kinds of animals at the bottom of the Lyse 

 Fiord, but there were no signs of life at the Mo Fiord bottom. 



In the Mo Fiord, the upper boundary for sea-weed did not 

 coincide with the shore-line; there was a distance of about 1.5 m., 

 down to the seaweed limit. Because of the very mixed state of 

 the surface water, the Mo Fiord beach looks like the shores of a 

 lake. No Mytilus edulis, Balanus balanoides nor Littorina are to 

 be seen on its beach. First at a depth of 1.5 m. are found a few 

 specimens of Littorina rudis on the precipitous rocks. The seawed 

 belt consists of Fucus serratus, the brackish water form of F. vesi- 

 culosus, which is also called F. ceranoides, etc. 



With respect to the occurrence of animal life, the Mo Fiord 

 may be divided into the following three belts: — 



— 1.5 m., no, or only exceedingly few, bottom animals, 



1.5 — about 50 m., comparatively prolific animal life, 



about 50 — 212 m., no animal life. 



This division is, on the whole, also useful when considering 

 the occurrence of plankton, except that sometimes plankton may be 

 found on the very surface, especially near the opening of the fiord. 



With regard to the samples of water tåken, it must be men- 

 tioried that one as far up as 60 m., could notice the smell of sul- 

 phuretted hydrogen in them 1 ). 



I will endeavour to give, on some later occasion, a more de- 

 tailed description of biologicai conditions in the Mo and similar fiords. 



*) The subject of the gases in the waters of the Mo Fiord is being dealt 

 with by Messrs. Lebedjnzeff and Helland -Hansen. The results of their inter- 

 esting investigations will soon be published. 



