Shell size average to small for the genus, outline of the shell stepped. Very light in weight. The protoconch is white with a sculpture of fine, hardly visible spiral striae. The suture is deep. The teleoconch whorls all have a shoulder. On this shoulder there is a sculpture of axial striae that form knobs on the shoulder itself. The rest of the whorls are covered with spiral lines and striae, covered with a fine axial sculpture. There is a big rib on the periphery, which gives the shell its stepped appearance. Base also covered with 6 spiral ribs, the umbilicus is open, wide and deep. There are 14 teeth on the umbilical keel. Aperture round. Base color of the shell is creamy white where in most specimen the upper whorls slightly yellowish tinted. The pattern consists of delicate flesh colored flecks and streaks, with in general some of them more pronounced on and near the shoulder.

In the Visayas Pseudominolia tramieri n. sp. is the closest to this species. However, the knobs around the lower keel of S. dedonderorum n. sp. and the shape of the body whorl distinguish both species at once.

TYPE LOCALITY
The Philippines, Mactan Island, Punta Engano.

DISTRIBUTION AND HABITAT
Known from Mactan, Caubian, Aliguay and the Camotes Islands. All taken between 10 and 180 m deep.