100 



THE OCEAN. 



In these latitudes the Hammer-headed Shark 

 {Zygcena malleus), a fish of singular construction, 

 attains a large size. In most particulars it closely 

 resembles the species just noticed, but the head is 

 widened out on each side into an oblong projection, 

 at each extremity of which is placed the eye. The 

 whole of this part has the form of a double-headed 

 hammer or maul. Undoubtedly one result of this 

 remarkable structure is a vast increase of the sphere 

 of vision ; but why a fish so formidably armed, and 

 endowed with such powers of motion, should be thus 

 favoured, we are not sufficiently accquainted with its 

 habits to determine. 



HAMMER-SHARK {Zijgcena malleus), and saw-fish {Pnstu antiquorum). 



