164 



BACKBONED ANIMALS. 



ing four filaments that twine about the sea-weed, prevent- 

 ing them from washing ashore. 



Torpedoes (Torpedimda). The fishes of this family 

 are electricians, and are common on the New England 



coast. The electric ap- 

 paratus (Fig. 201) is situ- 

 ated between the head 

 and the bases of the pec- 

 toral fins, and is composed 

 of numerous hexagonal 

 membranous tubes placed 

 side by side at right an- 

 gles with the surface of 

 the body, and so close to 

 it that their ends are 

 often visible above and 

 below. The cells contain 

 mucus, and are traversed 

 by nerves that proceed 

 from the eighth pair. So 

 powerful is this battery 

 that fishermen have been 

 knocked over as if with 



FIG. 201. The torpedo, with its elec- an axe > tne shocks also 

 trical apparatus displayed, b, bran- passing up the harpoon- 

 chiae; c, brain; ,, electric organ; of the knife used j n 



p-, cranium; me, spinal cord; , . , .,,.-, 



nerves to the pectoral fins; A cutting them. Allied are 

 nerves going to the electric organ ; Sting-rays ( TrygOtl), COW- 

 * eve - nosed rays, etc. The 



great devil < fish (Fig. 



202), that, has curious prolongations or claspers at 

 the head, attains a width of twenty-seven feet. They 

 have been known to tow large vessels against the wind 

 for long distances by fouling the anchor. The Japanese 

 use the skeletons of rays in the imitation of tortoise- 

 shell. 



