514 
THE OCEAN WORLD. 
fish are placed at the extremity of the lateral prolongations of the 
head : they are grey, projecting, and the iris is gold-coloured. When 
the anima l is irritated, the colours of the iris become like flame, to 
the horror of the fishermen who behold them. 
Beneath the head and near to the junction of the trank is the 
mouth, which is semicircular, and furnished on each jaw with three 
or four rows of large teeth pointed and barbed on two sides. 
The most common species in our seas is long and slender in the 
body, which is grey, the head blackish. It usually attains the length 
of eleven or twelve feet, weighing occasionally nearly five hundred 
Fig. 303 . The Hammerhead (Zygoma malleus). 
pounds. Its boldness and voracity, and craving for blood, are more 
remarkable than its size. If the hammerhead has not the strength 
of the shark, it surpasses it in fury ; few fishes are better knou n 
to sailors in consequence of its striking conformation. Its voracity 
often brings it round ships even in roadsteads, and near the coast. Its 
visits impress themselves on the memory of the sailor, and he loves to 
relate his hairbreadth escape from the meeting. 
The saw-fish is distinguished from all other known fishes by the 
formidable arm which it carries in its head. This weapon is a p r ° 
longation of the muzzle, which, in place of being rounded off ° r 
