Shell to 30.0 mm in length, fusiform-elongate and slightly cylindrical, teleoconch of ca. 8 convex whorls, protoconch unknown. Sculptured with 6-7 main spiral cords and 3-6 intermediate spiral threads on the penultimate and up to 35 primary and secondary cords on the body whorl and an additional 5-6 oblique cords on the siphonal fasciole; the smaller intermediate spiral threads are occasionally as large as the primary cords. Longitudinal grooves bisect spiral cords into laterally elongated beads, grooves deeper and slightly wider spaced on the spire whorls. Aperture slightly longer than the spire, narrow and elongate, smooth within, outer lip feebly crenulate, columella glazed and with 4-5 oblique folds. Ornamentation consists of alternating, broad or narrow, yellowish-brown and dull-white axial streaks, edge of outer lip yellowish-brown, aperture off-white.

The species is similar to Roseomitra rosacea Reeve, and differs mainly in the lack of interspaces which in D. sigillata are filled with close-set, secondary spiral threads. The radulae of the two species are prominently different.

Range - Japan. Subtidal, from 92-110 m.