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Epitoniidae Berry, 1910 (1812)

Cycloscala laxata

(G. B. Sowerby II, 1844)

Description:

Dimensions range from 7 mm - 20 mm high and 3.8 mm wide.
Width to height ratio: 0.54:1 ~ 0.19:1

Shell: conical; thin; minute to small. Exterior colour white. About 9 whorls, rounded, separated; protoconch with ~1.5 whorls convex smooth, white; teleoconch with 6-7.5 whorls ovate. Spire moderately elevated. Umbilicate: narrowly open. Approximately 10 - 19 costae on the body whorl. Costae are thin, fairly regular, lamellar, simple. Costae coronated. Intercostal spaces smooth, glossy. Aperture ovate, ovate-quadrate.

This species is close to E. (K.) laxatoides, but it is distinguishable by the smaller number of axial costae and its rather small size. [Nakayama, 2003], Nakayama [2003: 47] commented that this species species is similar to E. (K.) laxatoides, and can be differentiated in having fewer costae and a smaller size


Distribution:

Off Kii Peninsula Japan to the Philippines [Nakayama, 2003:47]; Korean Peninsular [NIBR, 2019:327]; Persian Gulf and Gulf of Oman [Melvill & Standen 1903].


Habitat:

27-285 m, amongst broken coral [Melvill & Standen, 1903:345].


Etymology:

[latin] from laxatus = loosened, slackened, spread out, slightly open.


Type Material:

Kaicher [1981: EP2-3080] identified BMNH 1981228 as a syntype, whereas the NHM online catalogue records the same specimen as the holotype [Natural History Museum, 2014: NHM 1981228].

Syntype: BMNH type collection 1981228 [as Epitonium laxatum (G. B. Sowerby II, 1844)]. [Kaicher, 1981: EP2-3080]
Holotype: NHM 1981228 [as Scalaria laxata G. B. Sowerby II, 1844] - Type Locality: Isle of Luzon, Philippines. [Natural History Museum, 2014: NHM 1981228]


SpeciesImage

Sowerby, G. B. II. (1844). Plate xxxii. Fig. 8.

Distribution

as listed in source literature

Sowerby, G. B. II. (1844).
Shown in text as Scalaria laxata G. B. Sowerby II, 1844
Species Image
Plate xxxii. Fig. 8.
Species Image
pp: 85.
Thin shell, slightly separate whorls: numerous, somewhat regular, laminated varices, simple; oval aperture: white in color."
Sowerby, G. B. II. (1873).
Shown in text as Scalaria laxata G. B. Sowerby II, 1844
Species Image
Plate vi. Fig. 38.
Species Image
Shell thin, smooth, white, whorls much disunited, varices numerous, thin, scarcely regular, laminated, simple; aperture
oval.
Tryon, G.W. (1887).
Shown in text as DDD
Species Image
Plate 11. Fig. 52.
Species Image
pp: 57.
Clessin, S. (1897).
Shown in text as Scalaria laxata G. B. Sowerby II, 1844
Species Image
Plate 1. Fig. 7.
Species Image
pp: 3.
Shell thin-shelled, smooth, white in color, with rounded whorls separated by deep sutures, increasing rather slowly and evenly; longitudinal folds numerous, thin, fairly regular, lamellar, simple; aperture egg-shaped.
Habitat: Luzon Island, Philippines.
Melvill, J. C. & Standen, R (1903).
Species Image
pp: 345.
Kaicher, S.D. (1981).
Shown in text as Epitonium laxatum (G. B. Sowerby II, 1844)
Species Image
Card #: EP2-3080.
Nakayama, T. (2003).
Species Image
pp: 125. Plate 11. Fig. 16.
Epitonium (Kriscala) laxatum (Sowerby, 1844)
height 7.0 mm; breadth 3.8 mm
off Kushimoto, Kii Peninsula, Japan, dredged at 100 m deep

Synonymy:

Epitonium (Kiiscala) laxatum (Sowerby, 1844) [Nakayama, 2003: 47]
Epitonium laxatum (G. B. Sowerby II, 1844) [Kaicher, 1981: EP2-3080]
Scala laxata G. B. Sowerby II, 1844 [Melvill & Standen, 1903a: 345]
Scalaria laxata G. B. Sowerby II, 1844 [Sowerby, 1844: 85; Brown & Neville, 2015: 95; Reeve, 1873: pl. 6, fig. 38; Clessin, 1897: 3; Tryon, 1887: 57; Natural History Museum, 2014: NHM 1981228]


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. (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]
Melvill, J. C. & Standen, R. (1903a). The genus Scala (Klein) Humphrey, as represented in the Persian Gulf, Gulf of Oman, and North Arabian Sea, with descriptions of new species.. Journal of Conchology. 10. Conchological Society of Great Britain and Ireland. https://www.biodiversitylibrary.org/page/31650162 [Accessed 26 February 2025]
Nakayama, T. (2003). A Review of Northwest Pacific Epitoniids. Monographs of Marine Mollusca. 6. Backhuys Publishers
Natural History Museum (2014). Collection specimens [Data set]. Natural History Museum. https://doi.org/10.5519/0002965 [Accessed 6 April 2026]
NIBR National Institute of Biological Resources, (2019). National Species List of Korea II. Vertebrates · Invertebrates · Protozoa. National Institute of Biological Resources.
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]
Weil, A., Brown, L. & Neville, B. (1999). The Wentletrap Book. Evolver
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