There are a number of Opalia species, including this one, that are difficult to separate on the basis of shell charac¬ters. It ranges from the Gulf of Aden south to Transkei, South Africa and has been found in beach drift and shallow water. It is white and reaches a maximum size of approximately 10mm. There are about 7 whorls with two weakly beaded keels on the body whorl. There are no strong axial ribs, although 1-2 varices per whorl are usually present. The suture is neither crenulated nor pitted. The surface is covered with finely pitted striae and the outer lip is thick.
While this species resembles O. bicarinata and O. crassilabrum, it differs in having a noticeable weakly nodular double keel.