Monacha nummus

shell large and flat, biconvex, shell colour grey to brown; protoconch consisting of two smooth whorls; teleoconch whorls with a dense pattern of white ribs, that extend to the glossy underside of the shell; suture marked by a white sutural thread; ca. six regularly increasing whorls, periphery with a sharply bounded crimped keel, sometimes spire stepped because of whorls attaching somewhat below the keel during shell growth; last whorl not descending; aperture obliquely oval with an acute palatal edge, sometimes with a faint white lip; peristomial rim sharply bounded and simple; umbilicus always open, narrow, with a broad periomphalum. Measurements. Syntype oxygyra: H = 5.91; D = 15.55; PH = 3.73; PD = 8.84. Fig. 5: H = 6.53; D = 16.15; PH = 3.39; PD = 8.67.

This species seems to be restricted to coastal regions in Lebanon.