PELAGIC ANIMAL LIFE 641 



libellula and Paratheniisto oblivia, the prawns Hymenodora 

 glacialis and Pasiphcea princeps are partly arctic, partly boreo- 

 arctic, and partly boreal in their occurrence, but in the present 

 state of our knowledge it is impossible to define sharply the 

 general laws of their distribution. In the year 1900 I made a 

 number of closing- net hauls in the Norwegian Sea, which 

 showed that there was a peculiar pelagic fauna in the deep 

 cold layer below the Gulf Stream, including the following large 

 forms : Cyclocaris guilelmi, Hy^nenodora glacialis, PasipJicea 

 princeps, and large Sagittae (.S". giganted). 



Of holopelagic fish there is not a single arctic species. 

 The coast fishes of Greenland, Spitsbergen, and other Arctic 

 shores may certainly be captured in the surface waters above 

 the coast-banks, but their life-cycle is not wholly pelagic. In 

 regard to one species only, Gadus saida (the polar cod), there 

 may be some doubt, for it lives everywhere along the ice 

 independent of depth, but it seems most feasible to classify it 

 among the Arctic shore-fishes. In the case of this fish the ice 

 apparently replaces the shore, a condition peculiar to many 

 other arctic forms. 



Highly important is the Capelan or Caplin [Mallohis villosus), 

 which lives in the Arctic or in the extreme north of the boreal 

 area, where it appears at all events once a year to deposit its 

 spawn on the coast banks. We may thus term it a meropelagic 

 fish of " boreo-arctic " character. 



The black Paraliparis batliybii has been taken by the 

 "Michael Sars " in mid-water in the Norwegian Sea, but 

 whether this species is mainly a bathypelagic or a bottom fish 

 cannot be decided from the available records. 



It has long been known that Atlantic species sometimes Atlantic 

 appear in the coast waters of Norway, and Nordgaard^ ^^s ^"JJJJ^Jj^ijjgg^ 

 published an interesting review of historical details of 

 this kind. Thus in 1821 salpae were observed by a certain 

 Norwegian priest, and between the 'twenties and 'forties of 

 last century when Michael Sars was engaged in his pioneer 

 work on the west coast of Norway, he found many Atlantic 

 forms, like Salpa nmcronata and S. fusiformis, well known by 

 the fishermen and termed " Silderaek," a portent of successful 

 herring fishery. Sars described from the west coast of Norway 

 some new species of Siphonophores and a larval Actinian 

 having their main distribution in the Atlantic, such as Galeolaria 



^ Kgl, Videnskapers selskaps skrifter, Trondhjem, 1910. 



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