FISHES, 



deep ponds, or tarns, of mountain districts. Of 

 Marine Fishes, some roam the wide ocean, some 

 play around the coral islands of the tropics, 

 others affect the mud, or the sands of the shal- 

 lows ; some linger near the estuaries of great 

 rivers ; others come in mighty armies around the 

 coast at particular seasons, retiring again to the 

 deep water in the offing ; finally, some habitually 

 keep near the surface, while others rarely rise 

 from the vicinity of the bottom. 



The form of a fish is that best calculated to 

 facilitate its progression through a fluid medium. 

 It is commonly that of a spindle, swelling in the 

 middle, and tapering to each extremity. There 

 are, it is true, many modifications of this form ; 

 some, as the Skates and Flat-fishes, are flattened 

 horizontally ; others vertically, as the Chgetodons 

 and the Dory ; some are globose, as the Diodons 

 and Sun-fishes ; some are drawn out into a ser- 

 pent-form, as the Eels and Lampreys ; and some, 

 as the Ribbon-fishes, resemble in length and 

 thinness the fabrics from which they derive their 

 name. Yet, in all these varieties the normal 

 form may, without difficulty, be traced. The 

 surface of the body is sometimes smooth, or 

 covered with a slimy secretion ; occasionally it is 

 armed with bony plates, which are sometimes set 

 with hard tubercles ; in a few species the body is 

 covered with spines, which are capable of being 

 laid close to the body, or erected at will ; but the 

 general covering of the body forms scales, or 

 rounded plates (apparently horny, but considered 

 by Professor Owen to be more allied to bone), 

 the front margins of which are imbedded in the 

 skin, and the posterior margins are loose and 



