HAMMER-HEADED SHARK. 223 



wengeance they does it. "Whether Master Whale has 

 offended them or not, it's hard to tell. If they eats him 

 they must have a tidy blow out off of him, but I don't 

 think they like the oil. I saw one engagement oft' the 

 Staples ; it was all two or three hours they was at it. 

 I don't think they leave him till they kill him." 



This story was told me in all good faith, but it will 

 not, I think, bear cross examination. Both species of 

 sword-fish — both the fellow that charges ships, the 

 Histiopherus, and the flat beaken sword-fish — do not 

 live in the cold water of the Arctic Seas. They are 

 both inhabitants of warm tropical or semi-tropical seas. 

 Nor, again, can I understand why the thresher-sharks 

 should attack the whale. All this requires investiga- 

 tion, but I fancy I have been able to explain the storj-. 

 (See Appendix, p. 384). n' 



The Hammer-headed Shark [Squalus zygccna, ZycjcBna 

 malleus, SqyaJe marteau ; French : Marteau coiinmtn) 



HAMMEK-HEADED SHARK. 



is a very rare British fish. The singular form of the 

 head, from which this genus obtains its name, at once 

 distinguishes it most unmistakably from all other fishes. 

 The head is truncated, and the sides extended horizon^ 

 tally into a kind of branch, the eyes being placed at 

 each extremity ; they thus look as if they were planted 

 on two thick peduncles. The head of the shark, as 



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