Anacithara tumida is a species of sea snail, a marine gastropod mollusk in the family Horaiclavidae.

(Original description) The ovate shell is thin.

The ribs are broad and rounded, well spaced, discontinuous from one whorl to another, nine on the penultimate whorl, gradually vanishing towards the base.

Both ribs and interstices overrun by fine dense spiral threads.

[2] This marine species is endemic to Australia and occurs off Queensland.