4.2mm. Compactly high spired with smooth, glossy, pointed protoconch of about 3 whorls (its 3rd whorl being conspicuously broader than 1st spire whorl). Gently swollen spire whorls bear low, regular, curved ribs (about 23 on last whorl) succeeded by greatly thickened peristome. Spiral threads between ribs revealed by high magnification. No umbilicus. Chalky white. Could be mistaken for a ribbed rissoid. Habitat: deep water. Distribution: Gulf of Oman.

Epitonium (Labeoscala) rissoinaeforme (Melvill & Standen, 1903) (Fig. 206) This tiny species, which reaches a maximum size of about 4mm, has been found in deep water in the Gulf of Oman. It is relatively heavy, with about 4 swollen teleoconch whorls and 3 protoconch whorls. The sutures are rather shallow. The costae are low and thin. The outer lip is very thick and the aperture is oval. The thin, low costae and shallow sutures separate this species from other members of this group.