R. auriscalpium has the smaller type of apex. The length of the shells varies: 3.3-8.0 mm. The shells are semitransparent and, except for occasional specimens, almost homogeneously coloured, whitish, horny or very pale brownish. In occasional shells faint, straight darker colour lines can be seen between the ribs on the body whorl. Punctate spiral striae are present in all full grown shells. These may cover the whole of the body whorl and more, or may be almost absent in small ribless shells, even at the base of the back. The lower 2-4 whorls are usually covered by rather flat and inobtrusive ribs, but shells in which these ribs are weak or absent are not rare. Usually, there are 8-9 terminal ribs per whorl, occasionally 7, 10 or 11. There is a well-developed labial rib. The aperture is expanded.

R. auriscalpium is not rarely washed ashore in the western Mediterranean; it also occurs in the Adriatic Sea.