116 CLASS-BOOK OF ZOOLOGY. 



§ 487. What use is made of the swimming-bladder ? How is isinglass 

 prepared ? 

 § 488. What rivers of the United States abound with Sturgeon? 

 § 489. What are the principal species of Sturgeons ? 



SECTION XXVIII. 



3d Order — Apodal Fishes : (Apodes.)* 



§ 490. Apodal Fishes are those which have a bony and 

 not cartilaginous skeleton, and are destitute of ventral 

 fins ; as the Eel, the Sword-fish, and many others. 



§ 491. All those fishes which have a long;, slender, and 

 slippery body, no ventral fins, and the caudal fin united 

 with the anal and dorsal fin, are called Eels. 



§ 492. Eels are found in all the seas of the world, as 

 well as in the mouths of rivers, and attain a length of ten 

 feet and more. They are in some countries an important 

 article of food ; and also of commerce, when broiled and 

 pickled. 



§ 493. The most singular of this species of fish is the 

 Electric Eel, (Gymnotus electricus,) which is from five 

 to six feet long, of a dark color, and possesses, like the 

 Torpedo, a truly electric power, by which it paralyzes 

 whatever living thing comes in contact with it. This fish 

 is found principally in the ponds and rivers of Surinam 

 and Cayenne. 



§ 494. The Sioord-jish, (Xyphias Gladius,) when full 

 grown, is from twenty to thirty feet long, without scales, 

 of a bluish-black color above, and a silvery color on the 

 sides, and having the upper jaw terminated by a sword- 

 shaped snout. It is found in the Mediterranean, as well 

 as in the Atlantic Ocean, in Africa and America. 



§ 495. The Sword-fish is mostly herbivorous, feeding 

 principally on sea-grass. Its flesh is much esteemed, and 

 is often found in the markets of New York. 



* Apodes is a Greek word, signifying without feet ; here indicating the 

 absence of the ventral fins. 



