The postmedial line double, often forming pale, indistinct crescent opposite claviform spot.

The reniform spot with incomplete thin black border, the interior slightly paler than the ground colour, with indistinct, darker inner ring.

The male hindwings are bright, slightly pearlescent white with the terminal third of the veins, and thin diffuse margin fuscous.

The female hindwings are duller white overall with more extensive fuscous shading on the veins and marginal area.

The species is named in honour of Thomas E. Dimock for his contributions to the knowledge of southern California moths.