GENERAL BIOLOGY 



779 



Another group of whalebone whales, the fin -whale 

 [Balcsnoptera p/iysalus), the humpback whale {Megaptera boops, 



Fig. 568. 



Greenland whale {BalcEtia viysticetus). (From Scoresby. 



Fig. 569. 

 /hale [Balcenoptera mnsculus). (From G. O. Sars.) 



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I' I 



'-v. 



■■V^.-jX1/!^Via.- 



Fig. 570. 



Cross-section of head of a fin-whale {Balieiioptera). (From Boas.) 



h, Head ; tt, lower-jaw ; b, whalebone ; fit, tongue ; f, furrows of the skin. 



Fig. 571), and the " saithe " whale i^B alcenoptera borealis) feed 

 on plankton as well as on pelagic fishes, mainly capelan and 

 herrings, which also constitute the main food of the small tooth- 

 whales of the porpoise description. 



