Cythara interstriata E. A. Smith, 1876 (original combination) Eucithara interstriata is a small sea snail, a marine gastropod mollusk in the family Mangeliidae.

This species can at once be recognized by the deep-brown suture, the band encircling the middle of the body whorl, which is continuous and not interrupted by the straight longitudinal ribs, and the paler band towards the base.

The spiral lirations are almost equidistant, and slightly nodulous on traversing the costae.

The columella is straight and is furnished with numerous small tubercles and transverse lirations, somewhat irregularly situated, the former, however, being near the exterior margin of the thin callosity which spreads out on the columella, and the latter further within the small and narrow aperture.

[2] This marine species occurs off the Solomon Islands.