This metallurgical trial was produced by the International Nickel Company in 1965. They were one of several companies looking to supply the U.S. Mint with a suitable alloy to replace silver. This is their second design, the other was P5335.
The obverse features a bust of Dr. Paul D. Merica and the reverse features his laboratory where the pieces were struck. The design was created by Gilroy Roberts and the hubs were created by the Medallic Art Company.
The coins are struck in 95% nickel, 5% silicon on a permalloy core of 79% nickel, 16% iron and 5% molybdenum with either plain edge P5377 or reeded edge P5378.
Photo courtesy of Heritage.