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Epitoniidae Berry, 1910 (1812)

Boreoscala rhytida

(Dall, 1917)

Description:

Dimensions range from 5.5 mm - 5.5 mm high and 2 mm wide.
Width to height ratio: 0.36:1 ~ 0.36:1

Shell: subcylindric; minute. Exterior colour pinkish white. About 10 whorls, rounded; strongly sculptured. Suture deep. Imperforate. Approximately 18 - 19 costae on the body whorl. Costae are low, thick, rounded, crenate. Intercostal spaces whorls spirally sculptured with flattish cords. Interstices with approximately 8 - 10 spiral striae per whorl. Base flattish, nearly smooth, bordered with a strong cord. Columella short and arched. Aperture subcircular. Operculum unknown.


Distribution:

Known only by one specimen from off the Galápagos Islands [Dushane, 1974].


Habitat:

73-1160 m [Kaiser, 1995].


Etymology:

[greek] from rhytis = wrinkle, meaning "wrinkled", in reference to the shell's sculptured.


SpeciesImage

DuShane, H. (1974). pp: 30. Fig. 52.

Epitonium rhytidum Dall, 1917
Holotype, USNM 207 604; length 6| mm; width 3 mm X 9.8

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 rhytidum Dall, 1917HolotypeUSNM 207604. San Cristobal Island, Galapagos Island, Ecuador. [Albatross Station 2808] Lat: -.6083, Lon: -89.32. 1159m. Collected by: United States Fish Commission. . 4 April, 1888. Trawled. [Smithsonian National Museum of Natural History, 2026: USNM 207604].USNM 207604. Galápagos Islands, Ecuador. 73-1159m [40-634 fthms]. [Brown & Neville, 2015: 132].USNM 207604. Galapagos Islands, Ecuador. [Dall, 1917: 486].USNM 207604. Galápagos Islands, Ecuador. [DuShane, 1974: 24].


Dall, W. H. (1917).
Shown in text as Epitonium rhytidum Dall, 1917
Species Image
pp: 486.
DuShane, H. (1974).
Shown in text as Epitonium rhytidum Dall, 1917
Species Image
pp: 30. Fig. 52.
Epitonium rhytidum Dall, 1917
Holotype, USNM 207 604; length 6| mm; width 3 mm X 9.8
Species Image
pp: 24.
Species Image
pp: 24.
Smithsonian National Museum of Natural History (2026).
Shown in text as Epitonium rhytidum Dall, 1917
Species Image
Fig. USNM 207604.
Epitonium rhytidum Dall, 1917
Holotype: USNM 207604
San Cristobal Island, Galapagos Island, Ecuador. 1159 m
Creator: Yolanda Villacampa
CC0

Synonymy:

Asperiscala rhytidum (Dall, 1917) [Kaiser, 1995: 4]
Epitonium rhytidum Dall, 1917 [Dall, 1917: 486; DuShane, 1974: 24; Brown & Neville, 2015: 132; Smithsonian National Museum of Natural History, 2026: USNM 207604]


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]
Dall, W. H. (1917). Notes on the shells of the genus Epitonium and its allies of the Pacific coast of America.. Proceedings of the US National Museum. 53(2217). https://www.biodiversitylibrary.org/page/7553869 [Accessed 18 September 2023]
DuShane, H. (1974). The Panamic-Galapagan Epitoniidae. The Veliger. 16 (Sup. 14). https://www.biodiversitylibrary.org/page/42500298 [Accessed 25 September 2023]
Kaiser, K. L. (1995). The recent molluscan marine fauna of the Islas Galapagos. The Festivus. 29. San Diego Shell Club. https://www.biodiversitylibrary.org/page/53297908?t=129924 [Accessed 7 August 2025]
Smithsonian National Museum of Natural History (2026). Invertebrate Zoology collections [Specimen database]. Smithsonian Institution. https://collections.nmnh.si.edu/search/iz/ [Accessed 22 August 2026]
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