Pusionella rapulum is a species of sea snail, a marine gastropod mollusk in the family Clavatulidae.

[2][3] The oblong shell is ovate The whorls are compressedly gibbous, forming a round shoulder, constricted and with revolving striae towards the base.

Otherwise, the shell is smooth, except that the upper whorls of the spire are slightly longitudinally plicate.

The color of the shell is whitish, under a very thin, smooth, yellowish brown epidermis.

There is a heavy, white callous deposit at the upper extremity of the inner margin of the aperture.