It appears in H. S. Crawford's 1913 inventory of early cross-slabs and pillars, described precisely enough to seem authoritative: an erect slab carved with a cross of circular arcs, surrounded by two circles, with a spiral design of four centres below. Cross-slabs of this kind are among the earliest forms of Christian stone carving in Ireland, simple upright stones incised with crosses and decorative motifs, and Inishglora, with its early monastic associations, would be a plausible home for one. The problem is that nobody has ever found it.

What makes the absence genuinely puzzling is that Inishglora was not an overlooked spot. The antiquarian John O'Donovan visited and recorded its monuments, as did T. Westropp and the art historian F. Henri, at various points between the late 1830s and the mid-twentieth century. None of them mention this slab. Crawford was compiling his inventory in the early 1900s, which opens one uncomfortable possibility: the slab was present just long enough to be noted, and was then lost or removed almost immediately. There is, however, a more intriguing explanation. Crawford's description closely matches a cross-slab recovered from Inishkea North, a neighbouring island, which is now held in the National Museum of Ireland. It is entirely possible that the attribution to Inishglora was simply a mistake, and that Crawford's entry and the Inishkea North stone are one and the same object, separated only by a cartographic error somewhere in the recording process. The slab, in other words, may be accounted for; it just may never have been where Crawford said it was.