Description: Shell discoid, planispiral, hardly depressed, relatively fragile, without prominences on a keeled periphery. Protoconch of about 1,25 smooth whorls, of about 443 µm diameter. Teleoconch of about 1,25 whorls, with a rapid increasing, dorsally with only numerous fine oblique ribs; ventrally with the same ribs and one spiral cord near the peripheral angulation, delimiting a depressed area. Sometimes there is another weakly prominent cord. Umbilicus very wide showing the previous whorls. Aperture oblique, with a sharp border in the outer lip and a continuous peristome. Dimensions: ADAM & KNUDSEN (1969) mention that 2.7 mm is the largest shell in their material. In our material some shells reach 3.0 mm.

There is no problem in the diagnosis of this species because it has the most depressed shell of the group. The most similar species are D. militare, D. radians, and D. exmilitare spec. nov., but none of them are so depressed and they have more prominent axial sculpture. D, mienisi has axial and spiral sculpture.

Distribution; Mediterranean, Mauritania and Liberia (after ADAM & KNUDSEN, 1969). We enlarge the range of this species to Senegal, Gambia, Congo and Angola, but it is not very common in these last countries.
GIANNUZZI-SAVELLI ET AL. (1997) mention Oran, Algeria, illustrating a shell from that area. It has been recorded from Israel by MIENIS (1981).