OF THE NORWEGIAN FISHEIUES : A REVIEW. 63 



west coast, in the latitude of Stavanger, attained the height of 9*5°. 

 In Christiania fjord the bank water lying below the thin surface 

 layer of Baltic water had a temperature of from ir5° to 12'2° C. 

 The chart for August in the same year shows, moreover, that the 

 Norwegian and Danish bank waters were continuous with one another 

 off the coast of Jutland, and that the temperature of the Norwegian 

 portion was almost as high as that of the Danish water (15°). 



There seems, therefore, to be no reason to doubt that the bank 

 waters of high temperature which enter the Skagerack in autumn 

 may consist of Norwegian as well as Danish water. The difficulty 

 which Cunningham has very pertinently raised in regard to the 

 association of herrings with purely Danish water would be satis- 

 factorily met by the explanation which Hjort's charts enable me now 

 to suggest. 



II. Plankton (Floating Fauna and Flora). 



Hjort's investigations of the distribution of plankton were confined 

 to the surface layers of the sea, his only available apparatus being a 

 simple net of fine silk gauze. Collections were made throughout the 

 year, principally from the west coast, but to some extent also from the 

 north coast, and from Christiania fjord. The results of his examination 

 of these collections are given in a series of tables and in a summary, 

 from which the author's opinions on his results may be gathered. 

 Hjort's conclusions, however, are cautiously expressed, and it would 

 be premature to regard any generalisations from the slender observations 

 which he records as at all final in character, although the accuracy of 

 the records themselves will enable them to be utilised for comparison 

 with future observations. 



1. The Baltic Current. — In summer, in Christiania fjord, the plankton 

 of the thick Baltic surface layer (temperature 17"2° C.) was found 

 (August, 1894) to consist principally of the Copepods, Halitemora longi- 

 cornis and Centro^pages hamatus ; the Cladoceran, Evadnc Nordmanni ; 

 and great numbers of Cilioflagellata, particularly Ccratinm tripos. On 

 the west coast, in July and August, 1894, the Baltic current (temperature 

 15°) contained few Cilioflagellata, but large numbers of the following 

 Copepods, Oalamcs finmarchicus, Centropages hamatus, Pseudocalanus 

 elongatus, and Faracalanus parvus, together with Evadnc Nordmamii and 

 Podon, Sagitta, Appendicularians, and a moderate number of Ivadiolaria. 



In the autumn, 1894, in Christiania fjord, the Baltic surface water 

 formed a thick layer, and in December (temperature 5*1°) contained 

 little except Cilioflagellata {C. tripos), which abounded. The deeper 

 layers also contained Sagitta. and a certain number of Diatomacefc. 

 On the other hand, in the autumn of 1893, the Baltic water was dammed 



