Height of holotype 1.18 mm, maximum height 1.7 mm.

Shell small, globular, fairly solid, transparent, skeneimorph. Larval shell consisting of about 0.5 whorl, diameter 250 mu and sculptured by small, sharp, branching tubercles, arranged in a spiral pattern which becomes more loosely arranged towards teleoconch. Adult teleoconch of about 2, almost smooth whorls, with some indistinct incremental lines. Adapical part of first whorl distinctly flattened and bearing a single spiral rib, which becomes indistinct and disappears on second whorl. Whorls rather tightly coiled, suture shallow. Aperture large, distinctly broader in lower part, prosocline and tangential. Umbilicus narrow, deep and open, sculptured by one slowly descending, outer spiral ridge and a more steeply descending and central rib, which eventually joins the inner lip.

The western Mediterranean and the adjacent Atlantic in 200-1000 m.

Despite that no soft parts have been examined of this species, the position of T. versiliensis in the genus Trochaclis is quite convincing because of the great similarity to the two known species of this genus for which radulae are known. Characteristic features of the shell are the spiral rib on the first teleoconch whorl, the shape of the tangential and prosocline aperture, and the sharp, descending ribs in the umbilicus.
Trochaclis versiliensis differs from T. islandica in having a more depressed spire, a more distinct spiral rib on the initial teleoconch whorl, and in having only two ribs in the umbilicus, where T. islandica has three ribs.