The dimensions of the apex are d = 0.10-0.13 mm. The largest shell ex¬amined measures nearly 3.5 mm. Small but seemingly full-grown shells may measure only 1.6 mm. The great majority of the shells is colourless and vitreous, or white. In such shells, the upper whorls have the same colour as the lower part of the shell, except for the nucleus of the apex, which may be tinged with brown. Often, three brown spots can be seen at the aperture. Moreover, a characteristic pattern of more or less weak yellowish colour lines and spots can be seen on the body whorl of part of the shells. Occasionally, part of the shell may be brown, or brown spiral bands may be present. Punctate spiral striae are well developed in some shells and weak to absent in others. The lower whorls of part of the shells are ribbed; such shells have a conspicuously inflated habitus. The number of ribbed whorls usually is about 1 to 2,5 ,but completely ribless shells are locally far from rare. There usually are 12-16 terminal ribs per whorl. A labial rib is absent.

R. scurra differs from R. similis in the larger dimensions of the apex, in the absence of shells which measure over 3.5 mm, in the absence of a labial rib, in the absence of purplish colours, in the colour pattern, and in the distribution. In particular the differences in the dimensions of the apex are very consistent among the large numbers of shells of both species examined. Shells of R. scurra with the characteristic colour pattern do occur at a number of different localities in the eastern parts of the Mediterranean. Though this colour pattern seems to be absent in R. lia, this is not sufficient proof for their distinct specific identity. Moreover, I did not find it always easy to distinguish in a satisfactory way specimens of R. scurra who lacked this colour pattern from certain forms of R. lia. Dr. J.J. van Aartsen, however, drew my attention to differences in the form of the first whorl. The nucleus of R. scurra is not as inflated and prominent as it is in well preserved apices of R. lia. Also, the dimensions of the apex on the average proved to be slightly larger in R. scurra. With the help of these characters, in combination with the colour of the upper whorls and apex, which tends to be different in R. lia, I no longer had difficulties in separating shells of both species in a satisfactory way.
If free from ribs and punctate spiral striae, shells of R. scurra are very similar indeed to those of Cingula alleryana (Aradas & Benoit, 1874), which, however, are somewhat differently coloured and have the whorls somewhat more strongly and evenly curved.

R. scurra is washed ashore quite numerously at many localities in the eastern Mediterranean. I also saw specimens from the Adriatic Sea, from Gandoli, 10 km S. of Taranto, S. Italy (Vrd 0108), and from Djerba, E. Tunisia