¹⁰Archaeologist Carleton Jones suggests that marble-size chalk balls found in the Fourknocks excavation, similar to those found in other tombs, may have been used within a ritual practice of placing the marbles into the cupmarks or other decorations on the stones. "Perhaps they were the 'eyes' of spirits or ancestors, which were only opened by performing particular rituals." (Jones, Carleton. Temples of Stone: Exploring the Megalithic Tombs of Ireland. Cork: Collins, 2007. 100.)
Martin Dier doubts that the megalithic artist intended to create a representation of a face. "When dealing with a culture as clearly sophisticated as is evident from the careful positioning of the massive stones, it is unlikely that they produced a crude face when clearly they could manage much more difficult tasks."
(Dier, Martin. "Fourknocks An Interpretation by Martin Dier." Knowth.com. Web. 2 Apr. 2011. <http://www.knowth.com/fourknocks-mdier.htm>.)