THE BERING SEA 841 



Table 328. Comparison of percentage composition of fauna of decapod Crustacea in 



Akhotsk and Bering Seas 



Group Sea of Okhotsk Ber T J "g fea «eluding 



r Unalashka Island 



Pan-Arctic, low Arctic, Arctic-boreal 



and low Arctic-boreal 36-4 33-7 



Sub- Arctic and sub- Arctic-boreal 10-4 4-4 



Pacific Ocean-glacial 7-8 3-4 



Total 54-6 41-5 

 Boreal (including subtropic-boreal 



for Sea of Okhotsk) 45-4 58-5 



Total 100 100 



in the Bering Sea. Decapod crustaceans and fish may be given as an example 

 {Table 329). 



Many other groups have great qualitative variety in the eastern part of the 

 Ocean. The fact that not all of them do so is interesting. Certain deep-water 

 groups are greatly varied in the eastern part of the Ocean. Pogonophora and 

 Echiuroidea certainly belong to these groups, and possibly some others. 



The great age and permanency of the Oceanic trenches, especially the 

 Pacific Ocean trenches, is proved, we think, by all the data given in this book, 

 particularly by the data on the Pacific Ocean fauna. Otherwise we would have 

 been unable to explain many phenomena which fully support this suggestion, 

 primarily the indubitable age of the geographical uniformities connected with 

 the temporary distribution of oceanic basins and of that of the oceanic flora 

 and fauna. 



The greater richness of Pacific flora and fauna compared with those of the 

 Atlantic ; the ancient, primitive aspect of its deep-water fauna, amphiboreal 

 and bipolar phenomena ; the ancient aspect of the uniformity of the vertical 

 distribution of fauna ; the harmony of the whole system of geographical 

 zonation, in other words of the biological structure of the Ocean : all these 

 indicate the long existence of the main features of the contemporary geo- 

 graphical distribution of the water masses of this ocean. 



Table 329. Distribution of decapod Crustacea and fish on eastern and western sides of 



Bering Sea 



Distribution Decapod Crustacea Fish 



Common to western and eastern coast 52-5 46-1 



Off western coast only 8-9 19-9 



Off eastern coast only 38-6 34-0 



