Syringopora centrocylindrica, n.sp., was found in life position in cemented orthoquartzite approximately 30 feet below the contact between the Pennsylvanian (Desmoinesian) Tensleep and the Permian Phosphoria Formations on the east margin of the Beartooth Mountains near Red Lodge, Mont. Tabulate corals seldom have been reported from the Tensleep and never before from its nearshore sandstone facies.