Click to enlargeJ268/P316

Although described as a regular dies trial piece in copper-nickel, it is more likely a mint error struck on an 1856 experimental half cent planchet for J177/P205, per Stacks 9/86, or a copper-nickel cent planchet.

Only a single example is confirmed ex Woodin-1914 ANS exhibit, Newcomer, Farouk, Paramount 11/73, NASCA 11/77, Stacks 9/86.

Photo courtesy of 2010 Whitman Publishing, from 100 Greatest U.S. Error Coins.