(Fig. 1 B, 1 I, 2 B, 4 B, 5 B, 6 B)
Type locality. Brazil (Santa Catarina).
Diagnosis. Male FW length range 41.3– 43 mm (based on specimens in Appendix 1). Wings with pale brown background from base through medial (FW) or postmedial areas (HW), turning darker brown distally. Overall background color slightly lighter than O. syme. FW with a conspicuous, orange ‘Y-shaped’ postmedial band that has a broad proximal arm, a well-developed (although broken) distal arm that intersects and obscures the subapical white spots, plus a thin submarginal band. HW with a well-developed orange submarginal band, plus a thin orange marginal band. Males have a HW discal cell hairpencil and a scent-pocket. Ventral HW with a faded white postmedial band distal to the eyespots. Females similar to, but paler than males dorsally, and devoid of iridescence.
Distribution. Brazil, São Paulo to Rio Grande do Sul (Testón & Corseuil 2002), Rio de Janeiro (Nova Friburgo, Petrópolis; K.S. Brown pers. comm.).
Remarks. Casagrande (2004) lists no subspecies for O. sulcius. Although the male genitalia are nearly identical to O. syme, differences were found in the female genitalia.