Through-stone (A).

A flat gravestone, a stone coffin or sarcophagus, also a bond stone which extends over the entire thickness of a wall. In architecture, called “Perpent” or “Perpend Stones” or “Throughs.” (French, Pierre parpainge.)

“Od! he is not stirring yet, mair than he were a through-stane.”—Sir W. Scott: The Monastery (Introduction).