Shell small, (all and narrow with an elongate protoconch. Whorls 12 including protoconch. Spire outline fairly straight, crenulated by the spirals. Sutures impressed but not particularly distinct. Protoconch of 3 whorls, greatly elongate, the first whorl smooth, the second two with widely spaced axials. Sculpture of teleoconch of four spiral cords crossed by close axials. Subsuttiral and suprasutural cords weaker, two middle cords strong. Third cord at first strongest but the two middle cords becoming subequal towards the body whorl. Axials close, some 28 on the body whorl, rendering the spirals nodulous. On the body whorl an additional smooth spiral emerges from the sutural zone. Base smooth. Aperture squarish, extended below into a short open canal. Outer lip sharp, columella strongly flexed to the left. Colour creamish. Height, 7,3 mm.; diameter, 1,9mm.

This species differs from the other known forms of Mendax in the details of the protoconch and the arrangement of the spiral sculpture. Although the protoconch in Mendax has three whorls, the first smooth and the following two sculptured with spaced axial riblets, no other species has the elongate form. The first whorl in trizonalis Odhner and duplicarinata Powell is globose and rounded on top, in stiria Webster it is globose and inflated, larger than the succeeding whorl. The arrangement of four nodulous spiral cords, the third the strongest is also distinctive.