42 JOHAN HJORT. M.-N. Kl. 



me, determine whether the Plankton present in the water has been 

 plentiful or other otherwise. In my tables, under the head »General 

 characteristics of the Plankton« I have, therefore, everywhere entered 

 whether the Plankton has been plentiful or not. One will understand 

 from the foregoing with what reservation these reports must be received. 



On some occasions I have also made vertical collections (for in- 

 stance in December 1894, at Fredriksvasrn), and in such instances I have 

 obtained very interesting results. 



In the following tables one will find, besides references to the same 

 investigations in the hydrographical tables and to the plates, accounts 

 of the saline contents and temperature of the water searched by the 

 Plankton net, and thereafter »General characteristics of the Plankton, as 

 well as »a specification of its most important forms.« 



Professor Dr. G. 0. Sars and Mr. H. Gran have been so kind 

 as to assist me in determining the Calanida and Algœ, for which 

 I am greatly indepted to them. During the revision it has not been our 

 intention to issue an exhaustive systematic list of the entire kinds of 

 Plankton, but only to note the most important sorts which were 

 present in considerable numbers, as well as what we, otherwise deemed 

 to be of interest. 



