In the 16th and 17th centuries, many parishes in Scotland owned a “common mortkist”–a reusable coffin to bury the poor. As the coffin was brought over the grave, a latch was opened, allowing the occupant to surreptitiously exit through a trap door bottom.
Some of the common coffins, like the one used by Linlithgow, had no lid, and the occupant may have had to have been covered using the parish mortcloth.
References
Walker, J.R. (1890) The common coffins at Abercorn and Linlithgow. Proceedings of the Society of Antiquaries of Scotland 24: 387-391