⁶¹Megalithic art motifs are often divided into "ten categories: five of which are curvilinear (circles, spirals, arcs, serpentiniforms and dot-in-circles) and the other five of which are rectilinear (chevrons, lozenges, radials, parallel lines and offsets)." ("Newgrange." Wikipedia, the Free Encyclopedia. Web. 30 Jan. 2012. <http://en.wikipedia.org/wiki/Newgrange>.)