The dual of the tiling represents the fundamental domains of orbifold symmetry. From symmetry, there are 15 small index subgroup by mirrorremoval and alternation operators. Mirrors can be removed if its branch orders are all even, and cutsneighboring branch orders in half. Removing two mirrors leaves a half-order gyration point where the removed mirrors met. In these images fundamental domains are alternately colored black and white, and mirrors exist on the boundaries between colors. The symmetry can be doubled to *∞42 by adding a bisecting mirror across the fundamental domains. The subgroup index-8 group, is the commutator subgroup of .