46 



FISH GALLERY. 



Wall- 

 case 4. 



Sting 

 Rays. 



mahogany rail in the middle of the Gallery). The maximum 

 breadth attained by the Torpedo is about three feet, and a fish of 

 this size can bv its electric discharge disable a man. 



':"-■'>■:■■■"'■ ■ '•■;.'■'■ 



Fig. 24. — Electric Ray, Torpedo marmorata. 



The Sting Rays or Trygonidse (fig. 25) have the pectoral 

 fins continued along the sides of the snout and confluent at its 

 extremity. The tail is slender and sharply marked off from the 

 disc, and has no lateral fold. The dorsal and caudal fins are 

 absent, or are feebly developed. A strong spine, barbed along its 

 sides, occurs on the upper part of the tail ; the spine is shed from 

 time to time, and is replaced by a younger one which has been 

 developing behind it. The tail-spine is used as a weapon of 

 defence, and severe lacerated wounds can be inflicted by it. 

 Similar spines are present in some of the Eagle Rays (family 

 Myliobatidae, Wall-case 3 ; see 125) . The Sting Rays are 

 mainly inhabitants of tropical waters, but one species, Trygon 

 pastinaca, 134, occurs off the British coast. Some of the American 



