Some malacologists place this genus more simply in the family Marginellidae.

He placed this species to the monotypic genus Extra Jousseaume, 1894.

Dautzenberg (1929)[3] moved this species into genus Marginella.

The shell is minute, white, semitranslucent; prominent axial costae present; spire sunken but not immersed; lip strongly thickened, smooth, lacking denticulation, flared posteriorly; siphonal notch absent; posterior notch absent; distinct parietal callus "shield" present; columella multiplicate, with 5 plications plus parietal lirae, plications slightly excavated inside aperture due to parietal callus deposits.

Recorded only from western Indian Ocean along Madagascar, apparently in shallow water.