Medium sized to large, heavy and solid. The sides are straight, the shoulder area convex. The spire is low, shows seven whorls, the last whorl slightly overlaps the previous one. There are fine spiral striae on the sutural ramps, but no grooves. The body whorl is smooth except for the anterior third where it has fine and dense spiral grooves. The aperture is rather narrow and straight, very slightly widening anteriorly. The shell is brown, with two paler narrow transverse bands, decorated with numerous conspicuous transverse lines of darker brown and white intermitted stripes. The shoulder is mottled with white and brown. The paratypes agree with this description, their condition does not allow an analysis of the shell's variability.

Conus medoci sp. nov. cannot be confused with any Indo-Pacific species on account of its unique transverse banding. Certain specimens of the Conus pulcher Lightfoot 1786-complex from West Africa may show a similar colorful banding, but this resemblance is probably incidental.

Conus medoci is known only from the vicinity of Lavonono in the extreme south of Madagascar. Two very fresh specimen were found on the beach (Paratypes 4 and 5), which suggest that the species inhabits the upper sublitoral zone.