CLASS V. PISCES: ORDER 1. SELACHIA. 



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in some it is rasp-like, in others studded with tubercles or spines, with which latter the tail is always 



armed. These fishes, some of which attain 

 to enormous dimensions, are admirably 

 adapted by their form for existing at the 

 bottom of the water on beds of sand or 

 mud. AVhen disturbed they slide along in 

 an undulatory manner, and with a slight 

 motion of the pectoral fins. They defend 

 themselves by lashing violently with the tail- 

 They are very voracious, feeding on fishes 

 and Crustacea, and upon shelleil or naked 

 mollusks. Their teeth are flattened and 

 lozenge-shaped, forming a serried phalanx 

 of points directed backward. So powerful 

 are the jaws that they are capable of crush- 

 ing the shell of a crab with the greatest ease. The females exceed the males in size, as in the 

 sharks : their eggs are corneous, and closely resemble those of the dog-fish. There are many 

 species distributed over nearly all seas. 



Genus TORPEDO : Torpedo. — To this belongs the Electric Ray, T. vulgaris., called Cranip- 

 Fish in England ; it is of considerable size, weighing from one to two hundred pounds. It is 

 remarkable for an electrical battery situated between the pectorals and head and gills ; this is 

 indicated by two elevations extending along the back, and consists of numerous cells formed like 

 honeycomb, this being, as is the similar provision of the Gymnotus or Electric Eel, amply supplied 

 with nerves. On being touched the animal imparts a severe electric shock, sufficient to stun 

 its prey. It is found in the European waters, and probably also on this side of the Atlantic. 

 There are about twenty species of this curious family in different parts of the Avorld, and all sup- 

 posed to possess electrical powers. It is said that one species is found on our coasts. 



THE ELECTBIC RAY. 



THE BORDERED RAY. 



THE SKATE. 



Genus RAIA : Raia. — This incudes the True Rays, of which there arc several species which 

 feed on fishes, mollusca, and Crustacea. The Bordered Ray, R. marginata, is two to three feet 

 long, including the tail. The flesh is tolerably good; common on European coasts. Other 

 species are the Homelyn or Spotted Ray, R. maculata ; Small-eyed Ray, R. microcellata ; 



