I have done more research and the facing figure is Mercury/Hermes and the creature on the back is a bull and the symbol above is the Mercury symbol with wear/corrosion obliterating most of the cross. See pictures.
It makes sense that the God of Messengers would be represented in a medallion that fits in the palm of your hand and may have been an official courier or messenger sign of recognition or passage.
As to its origin, just because it was found in Southeastern CT doesn't mean it originated there, since it was under a sort of "Shawshank Redemption" type stone, all of the items really have no provenance unless something attributable is discovered.

