Ok, maybe this will help a little to see...
That looks like maybe an internal mold (in hematite?) of a "Trepospira" snail. To the west of Bridgeport proper and nearer the lake the sediments and fossils are of "Pennsylvanian" Age about 300 million years old. In Bridgeport and east the sediments are of lower Cretaceous Age about 110 million years.