PLAGIOSTOMI OR SELACHII: EATS, ETC. 



257 



FIG. 297. 



6 eo el 



sm, 



Torpedo. 



5, brain; eo, eye and optic nerve; el, electric organs; sw, spinal nerves; sm, spinal 

 marrow; pg, pneumogastric nerves going to the electric organs; pg', branch ot the 

 preceding; 5-,' gills. 



FIG. 298. 



Saw-fish, Pristis antiquorum, Lath. 



from all other fishes a long, flat snout, armed oil each 

 side with pointed spines which are implanted like teeth. 



