3 5mm. Thick, short spired with glossy protoconch (mostly missing from available specimen). Spire whorls have thick, slightly oblique ribs (about 16 on last whorl), raised up just below sutures, each rib edge rope like; base encircled by a strong cord. Outer lip thick and broad. No umbilicus. Chalky white. Habitat: deep water. Distribution: Gulf of Oman

Opalia? (Pliciscala) corolla (Melvill & Standen, 1903) (Fig. 228) While the authors called this species a Cirsotrema, they noted that it strongly resembled O. diadema from the Gala- pagos. It was found in the Gulf of Oman at a depth of 156 fathoms. The shell is chalky white, with about 16 broad costae on the body whorl. The costae may be occasionally thickened and varix-like. The shell attains a height of 5mm. There is a strong basal ridge. The aperture is round and the outer lip is thickened. It is a stout little species with a broad outline. Fine spiral lines can be seen on the surface of the shell.