Unique tubercles low, without spines, having only 3 or 4 facets, the ridges between facet surfaces drawn out into scutes, each scute bordered by a comb of fine teeth. Disc margin short, 35% of SL (40% in S. erythrina and S. stellulata of equal size or larger). Tubercles along sides of tail shaped like toothed scutes, aligned in keel like series on each side of tail (Ref. 40826).