43 



COLLEGE ZOOLOGY 



FIG. 365. Sting-ray, Dasyatis sabina, dorsal view. 



Evermann.) 



(From Jordan and 



weapon of defense, and dangerous sidewise strokes can be made 



with it. 



The sting-ray, Dasyatis sabina (Fig. 365), lives half buried in the 



sand along the coast of Florida. 

 There is a barbed spine on its whip- 

 like tail which makes a painful 

 wound if driven into the hand or 

 naked foot. The torpedo (Family 

 TORPEDINID^E, Fig. 366) is inter- 

 esting because of the presence of 

 modified bundles of muscles (Fig. 

 366, EO] lying on either side of the 

 head which are capable of storing 

 up electrical energy and discharg- 

 ing it. The discharge of these elec- 

 tric organs is sufficient to paralyze 

 large animals ; they thus may serve 

 as weapons of offense and defense. 



FIG. 366. Torpedo with electric organ, EO, and brain exposed, dorsal 

 view. Br, branchial sacs; GR, sensory canal tubes of the skin; Le, electric 

 lobe of brain; O, eye^; Tr, trigeminal nerve; V, vagus nerve. (From Sedg- 

 wick's Zoology, after Gegenbaur.) 



