COLLECTION OF FISH. 427 



we possess fifty-seven species. The first sub- 

 genus is that of the lengthened shape ray (raia 

 rhinobatos}, whose body resembles that of the 

 saw -fish, and of which a species is found in the 

 Mediterranean; the others inhabit the seas of 

 South America, the Cape of Good Hope, and 

 Coromandel. The torpedoes or cramp rays, 

 \vhich form the second sub-genus, have the head 

 flattened in the form of a quoit, the mouth large, 

 short and fleshy. These forms ally them on one 

 side to the rhinobatos, and on the other to the 

 rays properly so called. 



The torpedo rays are celebrated for the fa- 

 culty which they possess of giving violent shocks 

 to those who touch them. The organ which 

 performs the part of an electrifying machine is 

 an apparatus of tubes divided by diaphragms into 

 little hexagonal cells situated near the head, 

 before the pectoral fins. 



The torpedoes give shocks to the animals 

 which disturb them ; and it appears that in this 

 manner they benumb those which they intend to 

 make their prey ; they have no other weapons. 

 Torpedoes are to be found in almost all the seas. 

 The largest, and that which gives the most vio- 

 lent shocks, lives upon the coast of the Cape of 

 Good Hope. The torpedo with five spots,* the 

 marbled torpedo, and the torpedo of Galvani in- 



