Holotype: “Zaghuah. Templo de las aguas. 14.2.72 Gasull leg. TUNIS”; RMNH no. 9007. — Paratype: same locality, date and collector; RMNH no. 9006. Description. — Length (in alcohol) of holotype 49 mm, length of mantle 15 mm, respiratory orifice about 10 mm from anterior border of mantle. Keel over the whole length of the dorsum as an extremely narrow whitish line and only clearly prominent near the end. The mantle and dorsum grey, merging into beige on the sides to become at the sole almost white; in the paratype the colour is somewhat lighter.