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Epitoniidae Berry, 1910 (1812)

Epitonium imperiale

(G. B. Sowerby, 1844)

Description:

Dimensions range from 11.28 mm - 40 mm high and 13.22 mm wide.
Width to height ratio: 00:1 ~ 0.33:1

Shell: broadly pyramidal, stout; thin and fragile; small to medium. Exterior colour pale fawn to purple- brown, sometimes weakly banded, costae white. About 8 whorls, large, rounded, contiguous; teleoconch with ~7 whorls convex. Suture deep. Umbilicate: deep, large, widely open. Approximately 25 - 35 costae on the body whorl. Costae are evenly spaced, low, thin, rather rounded some doubled in the last whorl. Costae elevated near the suture. Intercostal spaces smooth and glossy. Base with ribs extending on to the base. Aperture roundly ovate; peristome thin, complete. Operculum black, paucispiral.


Distribution:

Western Australia to southern Queensland (Wilson 1993: 277); Japan (Nakayama 2003: 71).; Japan, Philippines [Nakayama 2003: 71]; Cape Naturaliste, WA to Southern Queensland [Wilson 1993: 277]. Sowerby [1844:91], Clessin [1897:33], Tryon [1887:55], and Nakayama, 2003:71] all cite Mozambique as part of the distribution, however, Weil et al. [1999:134] believe this is in error as 'as no further specimens have been reported from the Indian Ocean'


Habitat:

Intertidal to offshore, buried in sand, associated with sea anemones


Etymology:

[latin] from imperialis = imperial


Type Material:

Syntypes: NHMUK 1981235 [as Scalaria imperialis G.B. Sowerby II, 1844:] - Type Locality: Mozambique and Swan River [Australia] (G.B. Sowerby II 1844b: 92).. [Brown, L. & Neville, B.D., 2015]


SpeciesImage

Murrell (2025).

Burrum Heads, Queensland, Australia
23.2 x 13.2mm

Distribution

as listed in source literature

Sowerby, G. B. II. (1844).
Species Image
pp: 91.
Original description
Sowerby, G. B. II. (1873).
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Plate i. Fig. 6.
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Scalaria imperialis. The shell is broadly pyramidal, perforated, ventricose, somewhat thin; with a few whorls increasing rapidly, between the varices purplish-brown; varices numerous, regularly spaced, somewhat rounded; with narrow spaces in between.
Tryon, G.W. (1887).
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Plate 11. Fig. 36.
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pp: 55.
Clessin, S. (1897).
Shown in text as Scalaria imperialis G. B. Sowerby II, 1844
Species Image
Plate 9. Fig. 8.
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pp: 33.
Shell broadly pyramidal, perforated, inflated, somewhat thin; whorls few, rapidly increasing, between the varices purplish-brown; varices numerous, regular, somewhat rounded, with narrow spaces between.
Kaicher, S.D. (1980).
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Wilson, B.R. (1993).
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pp: 379. Plate 44. Fig. 7.
Murrell (2025).
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Burrum Heads, Queensland, Australia
23.2 x 13.2mm
Species Image
Species Image

Synonymy:

Scalaria imperialis G. B. Sowerby II, 1844 [in Clessin, S., 1897].
Scalaria imperialis G.B. Sowerby II, 1844: [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]
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]
Kaicher, S.D. (1980). Epitoniidae I [Pack 23]. S. D. Kaicher, St. Petersburg, Florida. http://www.femorale.com/kaicher/species.asp?f=Epitoniidae&c=125 [Accessed 8 May 2023]
Murrell (2025). Personal Collection
Nakayama, T. (2003). A Review of Northwest Pacific Epitoniids. Monographs of Marine Mollusca. 6. Backhuys Publishers
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]
Sowerby, G. B. II. (1873). Monograph of the genus Scalaria. Conchologia iconica, or illustrations of the shells of molluscous animals, vol. 19, pls 1-16 and unpaginated text.. 19. London. https://www.biodiversitylibrary.org/page/8217819 [Accessed 24 August 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]
Weil, A., Brown, L. & Neville, B. (1999). The Wentletrap Book. Evolver
Wilson, B.R. (1993). Australian Marine Shells. Australian Marine Shells. 1. Odessey Publications
WoRMS Editorial Board (2025). World Register of Marine Species. https://www.marinespecies.org [Accessed 8 November 2025]

WoRMS direct page link: Open WoRMS record