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Epitoniidae Berry, 1910 (1812)

Epitonium symmetricum

(Pease, 1868)

Description:

Dimensions range from 3 mm - 12 mm high and 1.5 mm - 4 mm wide.
Width to height ratio: 0.5:1 ~ 0.33:1

Shell: elongate, acuminate; solid; microscopic to small. Exterior colour white. About 11 whorls, convex, contiguous; protoconch with ~5 whorls glassy; teleoconch with ~6 whorls convex. Suture moderately deep. Imperforate: umbilicus closed. Approximately 14 - 16 costae on the body whorl. Costae are thick. Costae continuous over the suture; slightly recurved. Intercostal spaces with fine spiral striae. Columella columella thickened and somewhat expanded at base. Aperture nearly circular.


Distribution:

Hawaii, Indo-Pacific, Cocos-Keeling Is [DuShane, 1988e:5]; Taiwan [Huang & Lee, 2016:19]; Tahiti [Tryon, 1887:66]; Gulf of Thailand [Wells et al., 2021:128].


Habitat:

Intertidal to 270 m; sand and coral [DuShane, 1988e:5].


Etymology:

[latin] from symmetricus = symmetric.


SpeciesImage

Academy of Natural Sciences (2025).

Holotype: ANSP 19586
Academy of Natural Sciences 19586

Distribution

as listed in source literature

Type Material:

The following list brings together type material and other cited specimens as reported in the sources examined, grouped under the names and designations used in each source. The same specimen may appear in multiple entries drawn from different sources. Some entries concern other species included by authors for comparison; inclusion in this list does not imply synonymy.
Epitonium symmetricum (Pease, 1868)HolotypeANSP 19586. Tahiti, French Polynesia. [Academy of Natural Sciences, 2025: 19586].
Parviscala symmetrica (Pease, 1867)HolotypeANSP 19586. Tahiti, French Polynesia. [DuShane, 1988e: 5].
Scalaria symmetrica Pease, 1867HolotypeANSP 19586. Tahiti, French Polynesia. [Brown & Neville, 2015: 145].


Pease, W. H. (1868).
Species Image
Plate 24. Fig. 14.
Species Image
pp: 290.
original description
Tryon, G.W. (1887).
Species Image
Plate 13. Fig. 12.
Species Image
pp: 66.
Maes, V. O. (1967).
Species Image
Plate 8. Fig. B.
Epitonium cf. E. symmetrica (Pease)
ANSP 287715, 3.7 mm
Academy of Natural Sciences, (2025).
Species Image
Holotype: ANSP 19586
Academy of Natural Sciences 19586
Species Image
Holotype: ANSP 19586
Academy of Natural Sciences 19586
Species Image
Holotype: ANSP 19586
Academy of Natural Sciences 19586

Synonymy:

Epitonium (Sodaliscala) symmetricum (Pease 1867) [Huang & Lee, 2016: 19]
Epitonium (Sodaliscala) symmetricum (Pease, 1868) [Wells et al., 2021: 128]
Parviscala symmetrica (Pease, 1867) [DuShane, 1988e: 5; DuShane, 1990: 9]
Scalaria symmetrica Pease, 1867 [Brown & Neville, 2015: 145; Pease, 1868: 290; Tryon, 1887: 66]


Source Literature:

Academy of Natural Sciences (2025). Holotype Epitonium symmetricum Pease 1867. ANSP Academy of Natural Sciences. http://clade.ansp.org/malacology/collections/details.php?mode=details&catalognumber=19586 [Accessed 29 March 2025]
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]
DuShane, H. (1988e). Hawaiian Epitoniidae pt.4. Hawaiian Shell News. 36(7). https://storage.googleapis.com/conchology-general-images/images/hsn/pdf/1988/8807.pdf [Accessed 29 October 2025]
DuShane, H. (1990). Hawaiian Epitoniidae. Hawaiian Shell News. 38(Sup.1). Hawaiian Malacological Society
Gemert L van (2003). Marine schelpen verzamelen op Ko Samui (Golf van Thailand). De Kreukel. 39
Huang, C. W. & Lee, Y.C. (2016). Checklist of the family Epitoniidae (Mollusca: Gastropoda) in Taiwan with description of a new species and some new records. Biodiversity Data Journal. 4. doi: 10.3897/ BDJ.4.e5653 [Accessed 25 August 2023]
Maes, V. O. (1967). The Littoral Marine Mollusks of Cocos-Keeling Islands (Indian Ocean). Proceedings of the Academy of Natural Sciences of Philadelphia. 119. Academy of Natural Sciences. https://www.jstor.org/stable/4064613 [Accessed 25 October 2025]
Pease, W. H. (1868). Description of sixty-five new species of marine Gastropodae, inhabiting Polynesia. American Journal of Conchology. 3(4). https://www.biodiversitylibrary.org/page/6659055 [Accessed 20 March 2025]
Tryon, G.W. (1887). Manual of conchology, structural and systematic with illustrations of the species. IX. Academy of Natural Sciences. https://www.biodiversitylibrary.org/page/11026889 [Accessed 20 September 2025]
Weil, A., Brown, L. & Neville, B. (1999). The Wentletrap Book. Evolver
Wells, E., Sanpanich, K., Tan, S. K, & Duangdee, T. (2021). The Marine and Estuarine Molluscs of Thailand. Lee Kong Chian natural History Museum
WoRMS Editorial Board (2025). World Register of Marine Species. https://www.marinespecies.org at VLIZ. [Accessed 8 November 2025]

WoRMS direct page link: Open WoRMS record