Another view of wings, showing venation of both forewing and hindwing. Arnett (1) keys this genus from Chauliodes based on wing venation, I believe. However the structure of the antennae is an easier (and consistent) character, as far as I can tell.

Summary of the relevant part of the key--the important couplet seems to be:
4(2)
-Median vein of hind wing with 3 branches reaching wing margin --->5 (Neohermes and Protochauliodes)
-Median vein of hindwing with 2 branches reaching wing margin-->6 (Nigronia and Chauliodes).

ID TBA--PC (post full-size image of hindwing median vein, if possible. Also check other individuals for this character.)