Protambulyx sulphurea
Described as an aberration of Protambulyx eurycles but most closely resembling Protambulyx ockendeni, but: Wings narrower and paler, pattern less contrasting. Forewing upperside lacking the large costal patches and subbasal patch on the inner margin of Protambulyx ockendeni. Forewing underside marginal band much narrower than in Protambulyx ockendeni, especially below M3. Hindwing upperside lemon yellow.
Male genitalia: Uncus produced mesally into very small lobe. Gnathos with lobe much narrower than in Protambulyx eurycles, sinuate mesally. Valve with patch of stridulatory scales broader dorsally than laterally (as in Protambulyx eurycles). Harpe armed with a high, erect, sub-mesal process, hollowed proximally and rounded at apex. Phallus with a dorso-lateral ridge appearing like a ribbon fastened to a sheath; free edge of ridge minutely notched; distally ridge extended along edge of phallus.