330 THE HAMMER-HEAD SHARK. 



The last of this family which seems to require mention 

 is the curious Zygaena, or Hammer-head, sometimes 

 called the Balance-fish. The Greeks named it Zygaena, 

 or the " balance," in allusion to the shape of its head. 

 Oppian refers to it as, 



" The monstrous balance-fish of hideous shape/' 



and gives it the palm over the lion for powers of de- 

 structiveness : 



"But what ! the lion? sharper weapons arm 

 The balance-fish, and keener furies warm " 



^Eliaii also dilates very fancifully on. the dangers to 

 which mariners are exposed from it. Certainly, it is ill- 

 looking enough to justify this unpleasant reputation; but, 

 in reality, the limited size of its mouth prevents it from 

 committing such havoc as is committed by the white or 

 blue shark. 



In shape it may be compared to the letter T, the 

 down-stroke representing the body, and the horizontal 

 bar its singular transvei'se head ; at the opposite ends of 

 which two very prominent yellow eyes are situated, com- 

 manding from their position a very considerable field of 

 vision. When the creature is irritated, these jaundiced 

 eyeballs suddenly change to blood-red, and staring in 

 their orbits, roll and glare in a very horrible manner. 



Beneath the head, and near its point of junction with 

 the body, lies the semicircular mouth, which is furnished 

 on each jaw with three or four rows of large teeth, 

 pointed and barbed on both sides. 



The most common species in our seas is long and 

 slender in the body, which is gray ; the head is blackish. 

 It usually attains the length of eleven or twelve feet, 

 weighing occasionally nearly five hundred pounds. 



