As Favartia planilirata:
The shell is of moderate size for the genus (maximum length 26 mm) and broadly fusiform. The spire is high and acute and consists of one and one-half sharply shouldered nuclear whorls and five weakly subangulate postnuclear whorls. The suture is well-impressed. The body whorl is of moderate size and fusoid. The aperture is of moderate size and ovate, with a modcratelv broad, shallow anal sulcus. The outer apertural lip is briefly erect and finely serrate, the serrations reflecting the sculpture of the shell. The columellar lip is largely detached and erect, but adherent at its posterior end; one or two low pustules may be apparent at the anterior end of the inner lip. The siphonal canal is of moderate length, slender, narrowly open, and bent dorsally.
The bodywhorl bears six moderately low, rather sharpcrested varices. Spiral sculpture consists of 13 moderately strong cords, almost square in cross section; each cord is separated from its neighbors by a deeply cut channel. The shell is covered with numerous fine axial-growth lamellae; and where the cords intersect the lamellae, partially erect scales are formed, these imparting a finely scabrous texture to the entire shell.
Shell color is off-white to pale tan-white, with a longitudinal band of purple-white after each varix and extending one-half to two-thirds of the distance across the intervarical space. The apertural margin is porcelaneous white; the above-mentioned darker longitudinal band is apparent more deeply within the aperture.

According to Ponder (1972), F. planilirata is distributed on the southern coast of Australia from Wilson's Promontory to Perth, Western Australia. Our specimens are from Woodman's Point, Cockburn Sound, ca. 4 km south of Fremantle (just south of Perth), Western Australia.