Eucithara eumerista is a small sea snail, a marine gastropod mollusk in the family Mangeliidae.

The shell contains 6 whorls, ventricose, roundly longitudinally costate.

On the body whorl there are just below the sutures brown spots between the ribs in one transverse line, and also subpellucid linear marking.

The outer lip and columella are both much denticled.

[2] This marine species occurs off New Caledonia, the Loyalty Islands and Queensland (Australia).