The dating of coarse pottery on Roman sites in the first and second centuries has been fairly well established, but there is still much uncertainty in the chronology of coarse ware during the third and fourth centuries. Hence it may be helpful to describe the pottery found in a Roman well which would appear, from the evidence to be adduced, to have remained open only during the third century. In my plan of Margidunum published in the Journal of Roman Studies, xiii, Pl. VIII, the position of this well, marked R, is shown to be situated halfway between the Via Quintana and the southern rampart. It lies just outside the eastern wall of a small building which may have been used as a stable, at any rate in the earlier occupation of the camp, for in the interior I found a pit (J) which had been filled up in the early part of the second century. The lower two feet contained brushwood, straw and horse-dung quite unaltered, owing to the pit having been hermetically sealed by clay. Doubtless this pit was closed when the camp was dismantled and the Fosse Way driven arbitrarily across it, over the old camp-roads and the foundations of the razed buildings.