208 



THE GEOGRAPHY OF MAMMALS 



to the Narwhal in many points of its general structure 

 (Fig. 50). These may be looked upon as quite isolated 



Fig. 50.— The Beluga. 



(Delphinapterus leucas.) 



[Flower and Lyd. Mamm., p. 262.] 



forms characteristic of the Arctic portion of the Atlantic 

 and Pacific. 



Section V. — Division of the Marine Area of the 

 Globe into Sea-regions 



From what has been already said, it will be evident 

 that although many of the marine mammals have a wide 

 distribution, others are very definitely localized; and a 

 study of the latter will enable us to divide the oceanic 

 portion of the globe into six Sea-regions, corresponding 

 to a certain extent with the six Land-regions already 

 discussed. It is proposed to name these Sea-regions, which 

 are shown in the map (Plate VIII., p. 216), as follows : — 



(1) The North Atlantic Sea-region, or Arctatlantis 

 (ap«To? and 'ArXavrU = the daughter of Atlas), consisting 

 of the northern portion of the Atlantic down to about 40° 

 N. lat. 



(2) The Mid- Atlantic Sea-region, or Mesatlantis {ixeaos 

 and ArkavTh), consisting of the middle portion of the 

 Atlantic down to about the Tropic of Capricorn. 



