Shell thin, opaque, ashy (when living perhaps translucent whitish), oval, smooth, four whorled; spire low, dome-like, not glazed over with callus; suture distinct, not channeled, slightly appressed: surface smooth, marked only by faint incremental lines; body whorl at the aperture thinly glazed but not callous; plaits oblique, distinct, three in number, the posterior weakest, the anterior continuous with the outer lip as it curves around the canal; siphonal fasciole, none; outer lip thin, very slightly reflected at its outer edge and scarcely thickened within, not denticulate; the outer margin of the lip is arched forward and outward; aperture wide, with a shallow anterior sinus and a narrow posterior commissure; maximum longitude of shell 14; maximum latitude 8MM.

This is a remarkably thin, simple, yet elegantly formed species. It is notable, among other things, for having but three plaits, for its absence of callus, and for its perfectly smooth outer lip. I do not recall any species of its own size with which it should be compared. There is a much smaller and probably unnamed species, dredged in deep water in the latitude of Fernandina, Florida, which has a very similar form. The thinness of the shell recalls M. fauna Sowerby and Volvarina pallida.

USA. off Cape Fear, North Carolina.