Vexillum stephanuchum is a species of small sea snail, a marine gastropod mollusk in the family Costellariidae (the ribbed miters).

These are smooth (to the naked eye), except where the spiral acutely noduled coronations encircle the upper part of the last five or six whorls.

These coronations gradually get fainter and disappear altogether in the upper whorls, which are many-ribbed, with interstitial transverse liration.

These lirae continue on the lower whorls, many-punctate, and the ribs on these last are fewer and very strongly marked.

[2] This marine species occurs off Oman and in the Persian Gulf; also off Pakistan.