CLASS-BOOK OF ZOOLOGY. 113 



$ 475. The empty eggs of the Shark are often seen 

 floating near the shores of the sea ; they are black, and 

 of a quadrangular form, like a pillow, with four corners ; 

 and to each one is attached a long black filament thirty or 

 forty inches long. 



§ 476. The flesh of the Shark, being coarse and of a 

 disagreeable flavor, is not eatable. The most useful part 

 of this fish is its liver, on account of its oil ; the liver of a 

 Shark about twenty feet long yielding from two to three 

 barrels. The skin of this animal, which is rough, is used 

 for polishing ivory and wood, and for making thongs and 

 other tackle for carriages, and shagreen. 



§•477. The Saw-Jish (Squalus Pristis) is a species of 

 Shark : it received its name from the flat, hard cartilagi- 

 nous prolongation of its snout, which is covered with a 

 leather-like skin, and set on either side with from 25 to 30 

 sharp teeth. 



§ 478. This saw-like weapon is usually half as long as 

 the body of the fish ; but Saw-fish have been seen, the 

 bodies of which were fifteen and the saw ten feet long. 



§ 479. The Saw-fish is very bold and courageous ; so 

 much so, that it attacks whales, and kills them after a 

 bloody battle. This animal is found in all the seas, but 

 principally near the shores of Africa. 



§ 489. The Hammer-headed Shark (Squalus Zygaena) 

 has its name from the form of its head, which is that of a 

 hammer, the eyes being placed at both extremities of it. It 

 grows to be six feet long, is very voracious, and inhabits 

 all the seas of the world. 



QUESTIONS ON SECT. XXVI. 



§ 460. What Fishes belong to the first Order? 



§ 461. What fish do you call Ray ? 



§ 462. Of what length, weight, and use is the Ray ? 



§ 463. What do you know of the eggs of the Ray ? 



§ 464. Where is the Ray found, on what does it feed, and what is its 

 disposition ? 



§ 465. Why is the Torpedo the most interesting species of the Ray? 

 What is its weight, and where is it found ? 



§ 466. What is the weapon of the Torpedo? 



§ 467. Where is the electric power of the Torpedo situated, and what 

 is seen there? 



§ 468. What are the form and number of the electric tubes of the Tor 

 pedo, and to what may they be compared ? 

 10* 



