Diloma

The five whorls are slightly convex, rapidly increasing and spirally obsoletely striate.

The base of the shell is rounded, eroded and iridescent in front of the aperture.

The outer lip is rather thin, not black-margined within; but bordered by a brilliantly iridescent band; The columella is concave, obsoletely subdentate below, very broad and flattened or excavated on the face.

It is composed principally of an opaque white layer which also lines the base but does not extend to the edge of the lip.

[3] This genus occurs in the Indo-Pacific, including New Zealand, Japan, and other areas.