The stone was documented in 1992 by Bradley and Dunne, who described it as a 17th-century slab measuring 1.65 metres long and 0.69 metres wide, set into the floor of the transept. When a researcher went to inspect it in June 2018, it could not be identified. It has not been moved to a museum, at least not on record. It has not been formally removed. It has simply become unlocatable, which is a quietly different thing.

What the slab carried, before it became unfindable, was a fragmentary inscription appealing for prayers on behalf of members of the Lynch family, one of the most prominent families in medieval and early modern Galway. The lettering, partly worn or broken away, reads: "[PRAY] FOR THE SOVLES / [OF] IOHN LYNCH & ... / BR... LYNCH ... WHOSE / ...N LYE HERE." The spelling of "SOVLES" and "IOHN" is typical of 17th-century funerary inscriptions in Ireland, where the letter I served for J and the older spelling conventions persisted in stone long after they had faded from manuscripts. The slab itself was reused in 1869, meaning it was likely lifted from its original position and relaid, perhaps as part of restoration or renovation work at the friary. That act of reuse, common enough in Irish ecclesiastical buildings, is part of what makes tracing it now so difficult; a stone reset once can be reset again, or covered, or built over.