H. chalcedonyx have the FW white patch narrower & upperside is marked with blue scales. Upperside FW white patch extends below vein 2 into space 1b. http://yutaka.it-n.jp/lyc4g/83173020.html
Additional note The only consistent difference in underside (based only on a couple of valid specimens each) is in H. albimacula. the FW white spot tend to be wider & its outer border have a mid angulation with a notch.
In H. chalcedonyx the white spot is narrower, its outer border regularly convex.
The two larger species H. syrinx & onyx have the foreleg tibia banded as the rest.