583 CHONDROPTERYGII. 



shaped. The mouth is generally placed far beneath the end of 

 the nose ; and the upper part of the tail is longer than the lower. 

 These fish are generally of a large size, sometimes almost 

 gigantic. They are carnivorous, and very voracious. Some 

 of them are universally dreaded on account of their ferocity, 

 their appetite for human flesh, their strength, and the formidable 

 array of teeth with which their mouth is furnished. These are 

 triangular, finely serrated, and exceedingly sharp, lying quite 

 flat in the mouth ; but when seizing their prey, are raised by 

 the action of muscles by which they are joined to the jaw. To 

 this, and the singular method in which these formidable creatures 

 are continued, we referred, however, in the general description 

 of the Fishes. The most useful part of these fishes is the liver, 

 from which oil is obtained ; a Shark twenty feet in length, yield 

 ing about two barrels. The rough skin is used for polishing 

 ivory and wood, and for making thongs, &c., for carriages; con- 

 verted into shagreen, it serves for covering small cases and 

 boxes. The flesh is not eatable, being coarse, and of a disagree 

 able flavor. 



The WHITE SHARK, Carcharias, (Gr. marine-dog,) vuJgoris or 

 Squalus Carcharias. found in tropical seas, has been known to 

 cut a man s body in twain at a single snap ; and it is stated that 

 human bodies have been found entire in the stomachs of these 

 terrible monsters. It is suggested, that their insatiate voracity 

 may result from the great quantity of gastric juice with which 

 they are supplied, causing them to digest with great rapidity, 

 and from the tape and other worms which abound in their intes 

 tines. Their sense of smell is acute, so that they discover their 

 victims at a distance; and they follow in the wake of ships for 

 the purpose of devouring whatever may be thrown or fall from 

 them into the sea. The White Shark is said to measure, some 

 times, thirty feet in length, and to exceed one thousand pounds 

 in weight. 



The THRESHER SHARK, Carcharias vulpes, has the upper part 

 of the tail nearly as long as the body, or even longer. The tail 

 is its principal organ of defence; it literally threshes its enemies. 

 Sometimes it is called the Fox-Shark, and the SWINGLE-TAIL. 

 This species, which is from twelve to fifteen feet in length, is 

 found on the coasts of North America as far North as Nova 

 Scotia. 



The SMALL BLUE SHARK, C. obscurus, from two to six feet in 

 length, is frequently taken on our coast. 



The MACKEREL PORBEAGLE or MACKEREL SHARK, Lamna, (Gr. 

 a plate,) punctata, has a pyramidal snout, with the nostrils 



