Shell large, elongate-conic. (Nuclear whorls decollated in all our specimens.) Postnuclear whorls well rounded, marked by narrow, lamellose, retractive axial ribs, of which 16 occur upon the first to fifth; 20 upon the sixth and the penultimate turn. These ribs form continuous lines on the spire. Periphery of the last whorl well rounded. Base with a single narrow spiral cord, a little anterior to the periphery. Sutures very strongly constricted; entire surface of spire and base marked by very slender incremental lines and exceedingly fine, microscopic, spiral striations. Aperture oval; outer lip thin'; inner lip thick; strongly curved and decidedly reflected; parietal wall covered by moderately thick callus, which renders the peristome complete.
The coloration of the type is as follows: A narrow band of brown separated from the summit by a white area, about as wide as the band. This band is only present in the intercostal spaces. The brown does not extend up on the ribs. A second, much wider band borders the basal cord posteriorly. A third, somewhat paler, is immediately anterior to the basal cord. In addition to these, a series of very obliquely slanting brown lines occur on the middle of the white space inclosed between the brown band at the summit and the cord immediately below the periphery. These markings appear much stronger with in the aperture.

While this species can be found intertidally with G. lamellosa, from Mozambique to South Africa, it is much less common than the latter species. It can be distinguished from G. lamellosa by having a brown line separated from the suture by a gap and brown dots or smudges of brown can be seen on the whorls on fresh specimens.