1. Gaster smooth; head sub-rectangular and not or indistinctly widening posteriorly (Figs. 5C, 6C). ……….. Pheidole spinosa, majors

-. Gaster at least partially shagreened; head sub-rectangular to cordate, indistinctly to distinctly widening posteriorly (Figs. 5A–5B, 5D and 6A–6B, 6D) ……….. 2.

2. Occipital lobe smooth, propodeal spines thin and acute, humeral tubercle well developed (Figs. 6D, 6H, 6L). ……….. Pheidole spinosa, supermajors

-. Occipital lobe at least partially (sometimes indistinctly) sculptured, propodeal spines minute and with wide base, humeral tubercle not or weakly developed (Figs. 6A–6B, 6E–6F, 6I–6J). ………….. 3.

3. Occipital lobes entirely to predominantly shagreened, at least first gastral tergite shagreened, head sub-rectangular with slightly convex lateral sides (Figs. 5B, 6B, 6F, 6J). ………….. Pheidole megatron

-. Occipital lobes predominantly smooth, first gastral tergite partially shagreened, head cordate and widening posteriorly (Figs. 5A, 6A, 6E, 6I). ………….. Pheidole megacephala