124 



SAW-FISHES. RAYS. 



Fig. 63. 



SHARK S HEAD. 



13. The White Shark, Squalus carcharias, which attains 

 twenty-five or thirty feet in length, is celebrated for its ferocity. 

 Its vast mouth, (Fig. 63.) is furnished with triangular, moveable 



teeth, the number of which increases with 

 age. In the young, we see but a single 

 row ; but, in the adult, we find six. The 

 strength of this fish is very great, and its 

 motions rapid ; its voracity knows no 

 bounds ; hence, it is among the most 

 dangerous animals. Men frequently be- 

 come the prey of sharks, and as many 

 as eight or ten tunnies have been some- 

 times found in its belly. eals, tunnies, 

 and cods, are their ordinary food; but 

 they attack dead bodies, and even devour 

 each other. It appears they are found in 

 every sea ; but voyagers often confound 

 with the carcharias, other species of sharks 

 with cutting teeth. 



14. The SAW-FISHES, Pristis, unite to the form of the 

 sharks, a body flattened in front, with branchial openings beneath, 

 as in the Rays, but they are especially distinguished by a very long 

 snout, depressed in form of a sword-blade, armed on each side 

 with strong bony spines, which are pointed and trenchant This 

 beak, from which they derive their name, is a powerful weapon, 

 with which they do not fear to attack the largest whales. The true 

 teeth of their jaws are like small pebbles, (Fig. 47, Page 94.) 



15. The Common Saw-Jtshi Squalus pristis, which is found 

 in almost every sea, attains a length of twelve or fifteen feet. Its 

 skin is tuberculous, of a very dark gray on the back, ash-colour 

 on the sides, and whitish under the belly. 



16. The RAYS, Raid, form a large tribe. Fishes of this 

 genus are recognised by their body being horizontally flattened, 

 and similar to a disk, a conformation which is principally due to 

 the disposition of their pectoral fins, which are extremely broad 

 and fleshy, and are joined to each other in front or to the muzzle, 

 and extend backwards on both sides of the abdomen, nearly to 

 the base of the ventral fins ; the eyes as well as the spiracles are 

 placed on the dorsal face : the mouth, the nostrils, and the open- 

 ings of the branchiae are on the ventral surface of the body ; and 



13. What are the characters of the White Shark? 



14. How are Saw-fishes distinguished? 



15. What are the characters of the common Saw-fish ? 



1 6. How is the genus of Rays recognised ? 



