Epitoniidae Berry, 1910 (1812)

Epitonium atomus

(E. A. Smith, 1890)

Description:

Dimensions range from 1.5 mm - 1.7 mm high and 1 mm wide.
Width to height ratio: 0.67:1 ~ 0.59:1

Shell: short; microscopic. Exterior colour white. About 4.5 whorls; protoconch with ~1 whorls smooth; teleoconch with ~3.5 whorls very convex. Suture deep. Umbilicate: narrow. Approximately 18 costae on the body whorl. Costae are thin. Columella margin slightly reflexed. Aperture obliquely ovate, base slightly flared; peristome continuous.

Distribution:

St. Helena Island

Habitat:

not reported

Etymology:

[greek] from atomus = a particle or a tiny, minute object

Type Material:

Syntypes: NHMUK 1889.10.1.574-92 [as Scalaria atomus E.A. Smith, 1890:] - Type Locality: St. Helena Island.. [Brown, L. & Neville, B.D., 2015]

SpeciesImage

Smith, E. A. (1890). Plate XXIII. Fig. 16.

Distribution

as listed in source literature

Smith, E. A. (1890).

Species Image

Plate XXIII. Fig. 16.

Species Image

pp: 274.

original description

Synonymy:

Scalaria atomus E.A. Smith, 1890: [in Brown, L. & Neville, B.D., 2015].

Source Literature:

Brown, L. & Neville, B.D. (2015). Catalog of the recent taxa of the families Epitoniidae and Nystiellidae (Mollusca: Gastropoda) with a bibliography of the descriptive and systematic literature. Zootaxa. 3907(1). Magnolia Press Auckland, New Zealand. http://dx.doi.org/10.11646/zootaxa.3907.1.1 [Accessed 22 October 2023]
Smith, E. A. (1890). Report on the marine molluscan fauna of the island of St. Helena. Proceedings of the Zoological Society of London. Proceedings of the Zoological Society of London. 2. Zoological Society of London. http://biodiversitylibrary.org/page/31014404 [Accessed 1 March 2025]
Weil, A., Brown, L. & Neville, B. (1999). The Wentletrap Book. Evolver
WoRMS Editorial Board (2025). World Register of Marine Species. https://www.marinespecies.org [Accessed 8 November 2025]

WoRMS direct page link: Open WoRMS record