6s8 



DEPTHS OF THE OCEAN 



The general results may be summarised as follows : — 

 In the northern North Atlantic we find Atlantic, boreal, and 

 Arctic forms. On our track from Newfoundland to Ireland we 

 met chiefly Atlantic species at the surface (see Station 92, 

 0-200 metres). In deeper water we find certain Atlantic 

 deep-sea species which nowhere in the ocean reach the surface, 

 mingled with boreal species. At Station 80, situated in an 

 area where the cold waters of the Labrador current communicate 

 directly with the deep bottom layers, the boreal forms occur at 

 all depths (Group 5), as they do in the Norwegian Sea; but to 

 the east of Station 80, where the warm layers are thicker, we 

 meet only the boreal forms in the deeper water, and in the 



Sargasso Sea at depths 

 Thus 



® 



© 



DISTRIBUTION OF CLIONE LIMACINA 



BETWEEN Newfoundland and the Sargasso Sea. 



The encircled figures denote the number of individuals 



captured. 



of 1000 metres. 



EuchcEta 



taken at all depths at 



Stations 80 and 113; at 



' (7y^_ /<?_" Station 92 only from 



1000 to 500 metres, and 

 at Station 62 only at 

 1000 metres. 



The genuine Arctic 

 forms (Group 6) occur 

 in waters with tempera- 

 tures below 5 or 6 C., 

 thus Caiantis hyper- 

 bore us was taken on 

 the Newfoundland 

 banks at the surface, 



at Station 80 only below 200 metres, and at Station 62 at 1000 

 metres. 



As shown in Chapter III., this conformity appeared even 

 during the cruise, and was obvious not only in regard to these 

 small crustaceans, but for quite a number of other boreal 

 and Arctic animals as well (see pp. 106-108 and 11 7- 11 8). 

 The most important boreal and Arctic forms encountered 

 between Newfoundland and Ireland, besides the Copepoda 

 previously mentioned, were : the medusa Aglantka, the 

 Ctenophores Bero'e, Pleurobrac/iia, and Mertensia, the worms 

 Sagitta arctica and Krohnia kamata, and the pteropods Liinacina 

 helicina and Clione limacina. 



During our voyage from the Sargasso Sea to Newfoundland 

 and thence to Ireland, Clione limacina was, according to 



