90 



PISCES. 



the fish itself, and capable of sustaining it in the air for a 

 considerable time. 



FAMILY III. SCOMBEROIDES. 



Scales small ; body smooth ; tail and caudal fin very vigo- 

 rous. Three remarkable genera. 



Genus I. Scomber. Mackarel. . 



Two small cutaneous crests on the sides of the tail ; an 

 empty space between the two dorsals ; five false fins above 

 and below. 



Genus TI. Thynnus. Tunny. 



A kind of corselet around the throat, formed by scales larger 

 and smoother than those of the rest of the body ; nine false 

 fins above and below. 



Genus III. Xiphias. Sword-Fish. 



A beak or long point, in the form of a sword or spit, ter- 

 minating the upper jaw, and forming a powerful weapon. 



FAMILY IV. ACANTHOPTERYGII, 



WITH LABYRINTHIFORM PHARYNGEALS. 



The superior pharyngeals divided into small lamelhe, more 

 or less numerous, irregular, intercepting cells in which the 

 water remains to flow upon and moisten the branchiae while 

 the fish is removed from its element. This permits it to seek 

 the land and crawl to a considerable distance from the water; 

 a singular faculty, which gave rise to the Indian belief that 

 these animals fell from heaven. 



ORDER IL MALACOPTERYGII ABDOMINALES. 



Upper jaw movable ; branchiae in combs ; rays of the fins 

 generally cartilaginous ; ventrals suspended under the abdo- 

 men and behind the pectorals, without being attached to the 

 bones of the shoulder. A numerous order, comprising the 

 greater part of Fresh-water Fishes. Five families. 



