Synonym: smithii Watson, who gives this huge description: « Shell small, with short, rounded, slightly depressed whorls, a spire which is a little scalar, fine translucent mucronate ribs, very delicate spiral threads, a slightly impressed little-oblique suture, and a rounded umbilicated base. Sculpture — Longitudinals: on the lower whorls there are about 20 fine sharply projecting translucent riblets, which run in a slightly oblique discontinuous line from whorl to whorl down the spire, on the earlier whorls they are somewhat fewer in number; on each riblet, slightly above the periphery, there projects a small nearly right-angled tooth – very often broken off. Spirals: there are about 15 to 20 very fine rounded little raised threads, which tend to become fainter about the periphery of each whorl. Colour saccharine white. Spire high and narrow. Whorls 6 (exclusive of those of the apex); they are rather short and tumid, markedly broader below than above, and are of very regular increase. Suture fairly impressed and rather oblique. Apex: 3 complete rounded whorls form a small high regular blunt cone on a small base set on a little to one side of the axis of the spire; these whorls are microscopically barred longitudinally. Mouth almost quite round, not small. Lip sharp-edged, not patulous, level-fronted, slightly detached (in the full-grown shell) from the body, and leaving behind it a small distinct funnel-shaped umbilicus. » – R. B. Watson: “On the marine Mollusca of Madeira; with descriptions of thirty-five new species, and an index-list of all the known sea-dwelling species of that island”, Journal of the Linnean Society of London, Zoology vol. 26(19), London 1897, p.253.