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Epitoniidae Berry, 1910 (1812)

Gyroscala xenicima

(Melvill & Standen, 1903)

Description:

Dimensions range from 3 mm - 31.2 mm high and 1.5 mm - 8.1 mm wide.
Width to height ratio: 0.5:1 ~ 0.26:1

Shell: tall, slender, fusiform, acuminate; thin and fragile; microscopic to moderately small. About 15 whorls, evenly convex, connected; protoconch orthoconic with ~4 whorls whitish, glassy, and very smooth; teleoconch with 8-11 whorls strongly and evenly convex. Spire with angle of 25 - 30 degrees. Suture impressed. Imperforate: umbilicus closed. Approximately 9 - 17 costae on the body whorl. Costae are thin, sharp, threadlike widely spaced, strongly arcuate, sinuous. Costae not aligned with the previous whorl. Intercostal spaces polished, with feeble, scratch-like spiral striae- sometimes obsolete. Base with well defined cord forming a strong keel [Melvill & Standen, 1903:348 and Beechey, 2008], while others describe it as a thin cord [Weil et al., 1999:12 and Nakayama, 2003:18]with some costae continuing into aperture. Columella thin, white, margin straight. Aperture elliptical, nearly round, pale brown inside; outer lip margin arcuate. Operculum unknown.


Distribution:

Australia, known from Albany Passage, Cape York, Queensland, southwards to Sydney NSW [Beechey, 2008]; off Kii Peninsular, Japan [Nakayama, 2003]; New Caledonia [Heros V. et al., 2007: 219]; Hawaiian Islands, Taiwan, South China Sea, Singapore, Natal, Zululand, Transkei, Gulf of Arabia, Gulf of Oman, Iran [Dushane, 1988]; East Florida to Brazil [Rosenberg et al., 2009]; Suriname [van Regteren Altena, 1975:27].


Habitat:

intertidal [Altena 1971: 81] to 285m [Melvill & Standen, 1903a: 348]; sand and Pinna beds [Dushane, 1990:1], soft substrates [Rosenberg et al., 2009: 642], sand and Pinna beds [Dushane, 1990:1].


Etymology:

[greek] from xenikoc = strange.


SpeciesImage

Natural History Museum (2014). Fig. NHM 1903.12.15.20.

Scala xenicima Melvill & Standen, 1903
NHM 1903.12.15.20
Chah Bahar, Makran coast, Iran
The Trustees of the Natural History Museum, London
CC0

Distribution

as listed in source literature

Type Material:

DuShane [1988h: 7] and Brown & Neville [2015: 1661] cite NHMUK 1903.12.15.20-21 as syntypes; however, the NHM online catalogue records it as holotype and paratype as a single entry, without differentiating between the individual specimens [Natural History Museum, 2014: NHM 1903.12.15.20-21].
Garcia [2003:25] considered Gyroscala xenicima (Melvill & Standen, 1903) and Gyroscala turnerae (Altena, 1971) to be "identical in their shell morphology, distinct coloration and a microsculpture unique in the genus Gyroscala." On the basis of these characters, he regarded Gyroscala turnerae (Altena, 1971) as a junior synonym of G. xenicima (Melvill & Standen, 1903).

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.
Gyroscala xenicima (Melvill & Standen, 1903)SyntypeNHMUK 1903.15.12.20. Gulf of Oman, Oman. Lat: 24° 58'N, Lon: 56° 54'E. 285m [156 fthms]. [Brown & Neville, 2015: 1661].NHMUK 1903.15.12.21. Mekran coast, Charbar, Iran. 9m [5 fthms]. mud bottom. [Brown & Neville, 2015: 1661].
Amaea (Acrilla) xenicima (Melvill & Standen, 1903)SyntypeBMNH 1903. 12. 15.20-21. Gulf of Oman, Oman. [DuShane, 1988h: 7].TypeGulf of Oman, Oman. [Nakayama, 2003: 18].
Epitonium (Gyroscala) turnerae Altena, 1971HolotypeNNM. [Brown & Neville, 2015: 153].Krofajapassie to 9½ km to the east, Wiawia beach, Suriname. [Regteren Altena, 1971: 80].ParatypeKrofajapassie to 9½ km to the east, Wiawia beach, Suriname. 5mm. [Regteren Altena, 1971: 80].Near Kat Creek, Suriname. 2mm. [Regteren Altena, 1971: 80].Near Popogaimama Creek, Suriname. 5mm. [Regteren Altena, 1971: 80].Near Toeholi Creek, Suriname. 5mm. [Regteren Altena, 1971: 80].Shell ridge, Coronieweg, picket 216, Suriname. [Regteren Altena, 1971: 80].Wiawia coast, west end of beach, Suriname. [Regteren Altena, 1971: 80].
Scala xenicima Melvill & Standen, 1903Holotype & ParatypeNHM 1903.12.15.20-21. Chah Bahar, Makran coast, Iran. [Natural History Museum, 2014: NHM 1903.12.15.20-21].


Melvill, J. C. & Standen, R (1903).
Shown in text as Scala (Opalia) xenicima Melvill & Standen, 1903
Species Image
Plate VII. Fig. 17.
Scala (Opalia) xenicima sp.n. (Pl. VII., fig. 17).
Species Image
pp: 348.
Regteren Altena, C. O. van (1971).
Shown in text as Epitonium (Gyroscala) turnerae Altena, 1971
Species Image
pp: 81. Fig. 4a, b.
DuShane, H. (1988h).
Shown in text as Amaea (Acrilla) xenicima (Melvill & Standen, 1903)
Species Image
pp: 9.
Amaea(Acrilla) xenicima(Melvill & Standen,1903)dredged 50 m Taiwan;length 18mm, width 6,I mm, DuShanecollec- tion,
Species Image
pp: 7.
Amaea (Acrilla) xenicima (Melvill & Standen,1903).Oahu, HI; length 8 mm, width 3 mm. Weil Collection.
Natural History Museum (2014).
Shown in text as Scala xenicima Melvill & Standen, 1903
Species Image
Fig. NHM 1903.12.15.21.
Scala xenicima Melvill & Standen, 1903
NHM 1903.12.15.21
Chah Bahar, Makran coast, Iran
The Trustees of the Natural History Museum, London
CC0
Species Image
Fig. NHM 1903.12.15.20.
Scala xenicima Melvill & Standen, 1903
NHM 1903.12.15.20
Chah Bahar, Makran coast, Iran
The Trustees of the Natural History Museum, London
CC0

Synonymy:

Amaea (Acrilla) xenicima (Melvill & Standen, 1903) [Kilburn, 1985: 426; DuShane, 1988h: 7; Nakayama, 2003: 18]
Amaea turnerae (van Regteren Altena, 1971) [Weil et al., 1999: 12]
Epitonium (Gyroscala) turnerae Altena, 1971 [Regteren Altena, 1975: 27; Regteren Altena, 1971: 80; Brown & Neville, 2015: 153]
Epitonium xenicima (Melvill & Standen, 1903) [Rosenberg et al., 2009: 642]
Scala (Opalia) xenicima Melvill & Standen, 1903 [Melvill & Standen, 1903a: 348]
Scala xenicima Melvill & Standen, 1903 [Natural History Museum, 2014: NHM 1903.12.15.20-21]


Source Literature:

Beechey, D. (2008x). Amaea_xenicima. Seashells of NSW. https://seashellsofnsw.org.au/Epitoniidae/Pages/Amaea_xenicima.htm [Accessed 10 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]
DuShane, H. (1988h). Hawaiian Epitoniidae pt.5. Hawaiian Shell News. 36(11). https://www.conchology.be/?t=5002&year=1988&volume=11&hsn=10345 [Accessed 16 September 2023]
DuShane, H. (1990). Hawaiian Epitoniidae. Hawaiian Shell News. 38(Sup.1). Hawaiian Malacological Society
Garcia, E. F. (2003). Gyroscala turnerae (Altena, 1971) (Gastropoda: Epitoniidae), a western Atlantic junior synonym of the Indo-Pacific Gyroscala xenicima (Melvill & Standen, 1903). American conchologist : quarterly bulletin of the Conchologists of America, Inc. 31(2). Lipps-National Press. https://www.biodiversitylibrary.org/item/321311 [Accessed 31 July 2026]
Garcia, E. F. (2003). New records of Indo-Pacific Epitoniidae (Mollusca: Gastropoda) with the description of nineteen new specie. Novapex. 4 (Hors-série 1). http://biodiversitylibrary.org/page/42322472 [Accessed 26 August 2023]
Heros V., Lozouet, P., Maestrati, P., von Cosel, R., Brabant D., & Bouchet P (2007). Mollusca of New Caledonia. in: Payri C.E. Richer de Forges B. (Eds.) Compendium of marine species of New Caledonia, Doc. Sci. Tech.. II7 2ed. https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers15-04/010038859.pdf [Accessed 28 February 2026]
Hutchings, P. & Ahyong, S. & Ashcroft, M. & Mcgrouther, Mark & Reid, A. (2013). Sydney Harbour: its diverse biodiversity. Australian Zoologist. 36. http://dx.doi.org/10.7882/AZ.2012.031 [Accessed 28 February 2026]
Kilburn, R.N. (1985). The family Epitoniidae (Mollusca: Gastropoda) in southern Africa and Mozambique. Annals of the Natal Museum. 27(1). Natal Museum
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). NHM Collection specimens [Data set]. Natural History Museum. https://doi.org/10.5519/0002965 [Accessed 6 April 2026]
Regteren Altena, C. O. van (1971). On six species of marine Mollusca from Suriname, four of which are new. Zoologische Mededelingen. 45 (5). https://repository.naturalis.nl/pub/319314/ZM1971045005.pdf [Accessed 26 June 2026]
Regteren Altena, C. O. van (1975). The Marine Mollusca of Suriname (Dutch Guiana) Holocene and recent Part III. Gastropoda and Cephalopoda. Zoologische Verhandelingen. 139. https://archive.org/details/zoologische-verhandelingen-139-001-104 [Accessed 26 June 2026]
Rosenberg, G., Moretzsohn, F. & García, E. (2009). Gastropoda (Mollusca) of the Gulf of Mexico. Gulf of Mexico: Its Origins, Waters, and Biota.Vol 1: Biodiversity. D. L. Felder & D. K. Camp, eds,. Texas A & M University Press
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