Here are actually two corals. The one listed in the picture is the hemispherical object but it is sitting on another coral.
Using Erwin C. Stumm's book Silurian and Devonian Corals of the Falls of the Ohio, pages 166-167 Figure 3 and described on page 76. It looks to be Platyaxum orthosoleniskum.
The other coral creature appears to be Propora papillata found on pages 146-147 and described on page 58.