68 



FISH GALLERY. 



other fishes of prey that would be likely to prove dangerous to 

 the Pilot. With regard to the statement that the Pilot itself is 

 never attacked by the Shark, all observers agree as to its truth ; 

 but this may be accounted for in the same way as the impunity of 

 the swallow from the hawk, the Pilot-fish being too nimble for the 

 unwieldly Shark. The Sea-bats [Plat ax), so called from the 

 extraordinary length of their dorsal and anal fins and of their 

 ventrals, are also remarkable members of this family. 

 case 13.] The Xiphiida, or Sword-fishes (Case 13), are pelagic fishes, 

 occurring in all tropical and subtropical seas. Several large speci- 

 mens are exhibited on the top of Cases 1-12. The Mediterranean 

 Sword-fish (Xiphias gladius), the flesh of which is considered to be 

 superior to that of the Tunny, and which is also abundant in the 

 Atlantic, is the object of a regular and profitable fishery, both in 

 Europe and America. The other species, which are found in the 

 open ocean, and endowed with extraordinary strength and swimming 

 powers, are less frequently captured, and still more rarely preserved. 

 They belong to the genus Histiophorus, which is distinguished from 



Fig. 52. 



Sword-fish of the Indian and Atlantic Oceans (Ilistiophorus gladuu). 



the common Mediterranean Sword-fish, or Xiphias gladius, by 

 the presence of ventral fins, which, however, are reduced to two 

 long styliform appendages. Some species have the dorsal rays 

 exceedingly elongate, so that the fin, when erected, projects beyond 

 the surface of the water : it is stated that these Sword-fishes, when 

 quietly floating with the dorsal fin erect, can sail before the wind, 



