Occasionally I come across large coral colonies while digging in the eroded remains of the Centerfield mbr. of the Ludlowville Formation near East Bethany, NY. The specimen below is fairly large at approximately 8" across by 4" wide. I think this is a colony of Favosites argus because of the small cell size of the corallites.
The Centerfield member of the Ludlowville formation is dated to the middle Devonian (Givetain stage).