I'm trying to identify a bayonet that I have. I can't find anything on it!?

I have a bayonet which has a ser. # E T49879C. It has a Phoenix on one side which is crowned and on the other it says Toledo with a bayonet coming down threw the word Toledo seperating the word in half. And below the that I.N.I. Is spelled out. The sheath is hard and is a metal alloy. The blade is black and is 18" aprx.in length. I have checked several websites with no luck. Can you help direct me in the right direction or even better help me identify this bayonet. My curiousity on the history of this has been eating at me for years. Thanks