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Epitoniidae Berry, 1910 (1812)

Epitonium dubium

(G. B. Sowerby II, 1844)

Description:

Dimensions range from 15 mm - 20 mm high and 7.5 mm wide.
Width to height ratio: 0.5:1 ~ 0.38:1

Shell: short, ventricose, pyramidal; thin and fragile; small. Exterior colour pale grey, with a yellow margin of the aperture. About 9 whorls, barely separated whorls; teleoconch with 7-9 whorls. Spire elevated pyramid. Suture deep. Umbilicate: small, fenestrated. Approximately 42 costae on the body whorl. Costae are very thin, threadlike, numerous, oblique, almost obsolete in the middle. Costae elevated near the suture; reflexed. Intercostal spaces with numerous spiral striae. Base strongly convex. Aperture large, roundly ovate; peristome double, with a thin callus; outer lip margin roundly arcuate, thin; inner lip strongly foliaceous, continuous.

Kaicher [1981] comments that this species may be confused with E. irregularis


Distribution:

Off Kii Peninsula to Okinawa, southern part of Sea of Japan; Philippines [Nakayama, 2003:75]; Flores Sea Indonesia, and Northern Territory, Australia [Boury, 1912b: 95].


Habitat:

on reef, intertidal to 20 m, sand[Nakayama, 2003:75].


Etymology:

[latin] dubium = doubtful, ambiguous, the usage of the word reflects uncertainty.


Type Material:

Holotype [probable]: NHMUK 1981234 [as Scalaria dubia G.B. Sowerby II, 1844] - Type Locality: Ticao, Philippines, per G.B. Sowerby II (1844a: 13). [Brown, L. & Neville, B.D., 2015]
Holotype [probable]: BMNH 1981234. Sowerby stated he had only a single, imperfect specimen for Epitonium dubium (G. B. Sowerby II, 1844). [Kaicher, S.D., 1981]
Type not indicated in text [as Foliaceiscala dubium (SOWERBY II, 1844-a)] - Type Locality: 'Ticao, Philippinarum' (Ticao, Philippines); 'Taken on reefs'. [Higo, S., Callomon, P. & Goto, Y., 1999]


SpeciesImage

Sowerby, G. B. II. (1844). Plate xxxiii. Fig. 41.

[Nakayama, 2003:75]

Distribution

as listed in source literature

Sowerby, G. B. II. (1844).
Shown in text as Scalaria dubia G. B. Sowerby II, 1844
Species Image
Plate xxxiii. Fig. 41.
[Nakayama, 2003:75]
Species Image
pp: 90.
original description
Sowerby, G. B. II. (1873).
Shown in text as Scalaria dubia G. B. Sowerby II, 1844
Species Image
Plate vii. Fig. 45.
Species Image
Species 45. (Mus. Brit.)
SCALARIA DUBIA
Tryon, G.W. (1887).
Species Image
Plate 12. Fig. 67.
Species Image
Plate 12. Fig. 68.
Species Image
pp: 60.
Clessin, S. (1897).
Species Image
Plate 10. Fig. 7.
Species Image
pp: 35.
Boury, E. de. (1912b).
Shown in text as Scalaria (Foloaceiscala) dubia G. B. Sowerby II, 1844
Species Image
Plate VII. Fig. 4.

Synonymy:

Epitonium dubium Röding, 1798 [in Brown, L. & Neville, B.D., 2015].
Foliaceiscala dubium (SOWERBY II, 1844-a) [in Higo, S., Callomon, P. & Goto, Y., 1999].
Scalaria (Foloaceiscala) dubia G. B. Sowerby II, 1844 [in Boury, E. de, 1912b].
Scalaria dubia G. B. Sowerby II, 1844 [in Reeve, L. A., 1873].
Scalaria dubia G. B. Sowerby II, 1844 [in Sowerby, G. B. II., 1844].
Scalaria dubia G.B. Sowerby II, 1844 [in Brown, L. & Neville, B.D., 2015].


Source Literature:

Boury, E. de (1912b). Description de Scalidae Nouveaux ou Peu Connus Pt 2. Journal of Conchology. 60(2). https://www.biodiversitylibrary.org/item/55204 [Accessed 4 July 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]
Clessin, S. (1897). Die Familie der Scalariidae. In W. Kobelt (Ed.), Systematisches Conchylien-Cabinet von Martini und Chemnitz. Neu herausgegeben und vervollständigt. 2(13). Bauer & Raspe, NürnbergBauer & Raspe, Nürnberg. https://www.biodiversitylibrary.org/page/34259905 [Accessed 21 June 2025]
Higo, S., Callomon, P. & Goto, Y. (1999). Catalogue and Bibliography of the Marine Shell-Bearing Mollusca of Japan.. https://www.researchgate.net/publication/266375656_Catalogue_and_Bibliography_of_the_Marine_Shell-Bearing_Mollusca_of_Japan [Accessed 25 July 2025]
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]
Nakayama, T. (2003). A Review of Northwest Pacific Epitoniids. Monographs of Marine Mollusca. 6. Backhuys Publishers
Reeve, L. A. (1873). Monograph of the genus Scalaria. Conchologia iconica, or illustrations of the shells of molluscous animal. 19. London. https://www.biodiversitylibrary.org/page/8217819 [Accessed 24 August 2023]
Sowerby, G. B. II. (1844). Monograph of the genus Scalaria.. Thesaurus conchyliorum, or monographs of genera of shells.. 1 (4). London, privately published.. http://biodiversitylibrary.org/page/11076419 [Accessed 22 June 2023]
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]
WoRMS Editorial Board, (2025). World Register of Marine Species. https://www.marinespecies.org [Accessed 8 November 2025]

WoRMS direct page link: Open WoRMS record