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Epitoniidae Berry, 1910 (1812)

Epitonium antisoa

(Iredale, 1936)

Description:

Dimensions range from 10 mm - 20 mm high and 7.5 mm wide.
Width to height ratio: 0.75:1 ~ 0.38:1

Shell: slender, narrowly pyramidal; thin, polished; small. Exterior colour white and glassy, costae white. About 13.5 whorls, strongly rounded, joined; protoconch with ~4.5 whorls whorls missing; teleoconch with ~9 whorls strongly rounded. Suture deep but simple. Umbilicate: open behind columellar callus, smooth. Approximately 15 - 18 costae on the body whorl. Costae are prosocline, fine, thin, low, erect, distant rather insignificant but sometimes thickened. Costae not peaked, slightly higher below suture where they form a weak angle; discontinuous, not aligned between whorls. Intercostal spaces thin, low, somewhat tabulate spiral threads, missing below the suture and the base of last whorl. Interstices with approximately 7 - 15 spiral striae per whorl. Fasciole absent. Aperture ovate, oblong-ovate; peristome thin, no auricle; outer lip with thick rib externally; inner lip labium barely reflexed.


Distribution:

Transkei, South Africa; NSW & Queensland, Australia. Australian specimens only recorded form Zilzie Point, Keppel Bay & Sydney Harbour [Beechey, 2008]


Habitat:

offshore 30- 50 m [Kilburn, 1985:311]. Queensland specimens are empty beach shells [Beechey, 2008]


Etymology:

May be derived from a Malagasy word meaning beautiful or pleasant


Type Material:

Holotype: AMS C.60654 [as Folaceiscala antisoa Iredale, 1936:] - Type Locality: Sydney Harbour, New South Wales, Australia.. [Brown, L. & Neville, B.D., 2015]


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Iredale, T. (1936). Plate xxii. Fig. 16.

Distribution

as listed in source literature

Iredale, T. (1936).
Shown in text as Folaceiscala antisoa, sp. novo
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Plate xxii. Fig. 16.
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pp: 300. Plate xxii.
Kaicher, S.D. (1981).
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Card #: EP2-3055.
Beechey, D. (2008).
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pp: Epitonium antisoa. Fig. 1.
Holotype: Sydney Harbour, dredge Triton (C.060654)
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pp: Epitonium antisoa. Fig. 2.
Holotype: Detail of sculpture

Synonymy:

Folaceiscala antisoa Iredale, 1936: [in Brown, L. & Neville, B.D., 2015].
Folaceiscala antisoa, sp. novo [in Iredale, T., 1936].


Source Literature:

Beechey, D. (2008). Shells NSW -Epitonium_antisoa. https://seashellsofnsw.org.au/Epitoniidae/Pages/Epitonium_antisoa.htm [Accessed 8 May 2023]
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]
Iredale, T. (1936). Australian molluscan notes. No. 2.. Records of the Australian Museum. 19(5). Australian Museum, Sydney. doi:10.3853/j.0067-1975.19.1936.704 [Accessed 14 September 2023]
Kaicher, S.D. (1981). Epitoniidae II [Pack 30]. S. D. Kaicher, St. Petersburg, Florida. http://www.femorale.com/kaicher/species.asp?f=Epitoniidae&c=125 [Accessed 8 May 2023]
Kilburn, R.N (1985). The family Epitoniidae (Mollusca: Gastropoda) in southern Africa and Mozambique. Annals of the Natal Museum. 27(1). Natal Museum
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