54 NATURAL HISTORY. 



long smooth sword, armed on each side "with strong bony 

 spines resembling teeth. This beak, from which they 

 derive their name, is not unlike a carpenter's saw, and 

 proves a powerful weapon in the frequent battles it 

 maintains with dolphins and whales ; these contests are 

 fearfully violent, and obstinately continued until death 

 decides the victory. The saw fish is mostly conqueror, 

 as he thrusts his formidable saw into the vitals of his 

 victim. The whale fishermen watch these battlings with 

 much interest, and, when ended, pursue the saw fish, 

 which not seldom breaks his saw. This fish is about 

 fifteen feet in length, dark gray, and smooth. Their 

 true teeth are small, and look like a pavement made of 

 pebbles, therefore it is probable that they live principally 

 on crabs and shell fish. 



The Balance Fish (squalus zygsena), plate 20, fig. 8, 

 has a body and fins resembling those of the shark, from 

 which it is sometimes called the Hammer-headed shark, 

 from the peculiar form of its head, which has a singular 

 prolongation on each side, resembling a hammer, on 

 which the eyes are placed ; the teeth are sharp and tri- 

 angular. Its length is often that of a man, sometimes 

 greater ; is rough, gray, and lives mostly in the Medi- 

 terranean, preferring muddy spots. It is viviparous, 

 producing about a dozen living young ; very rapacious, 

 and the flesh not particularly good. A scarcely less 

 numerous race is that of 



THE RAYS, 



Recognized by their flattened bodies and long slender 

 tails. The mouth lies under the long muzzle, the small 

 eyes above, on the head; and behind these are two bran- 



