Later authors have generally regarded Tetronarce as a subgenus of Torpedo .
In 1861 , Theodore Gill placed this species in his newly created genus Tetronarce , on the basis of its smooth - rimmed spiracles .
Later authors have generally regarded genus as a subgenus of Torpedo .
In 1861 , Theodore Gill placed this species in his newly created genus Tetronarce , on the basis of its smooth - rimmed spiracles .