This image is of a Favosites (Emmonsia) emmonsi colonial coral fossil. It was found in the Jeffersonville Limestone of Clark County Indiana USA. The fossil dates to the Devonian Period.
This fossil was on display at the Falls of the Ohio State Park Interpretive Center as of January 2016. This coral is one of over 200 species that were known to live in this area over 300 million years ago.