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Epitoniidae Berry, 1910 (1812)

Epitonium acapulcanum

Dall, 1917

Description:

Dimensions range from 4 mm - 10 mm high and 1.9 mm - 4.5 mm wide.
Width to height ratio: 0.48:1 ~ 0.45:1

Shell: acute; thin; minute to small. Exterior colour white. About 9 whorls, well-rounded; protoconch with ~3 whorls smooth, glassy; teleoconch with 5-6 whorls. Suture moderately deep. Imperforate: lacking. Approximately 11 - 15 costae on the body whorl. Costae are low, thin, sharp. Costae continuous over the suture; without spines at the shoulder; slightly reflected. Intercostal spaces with spiral sculpture of flattish adjacent threads with some continuing on to the costae. Interstices with approximately 8 - 12 spiral striae per whorl. Fasciole at the anterior end of lip is strong, wrinkled. Aperture round. Operculum thin and paucispiral.

Dushane [1974] discusses the comparison of the holotype of Epitonium (Asperiscala) acapulcanum Dall, 1917, presumably from Acapulco, Mexico, with the types of E. (A.) xantusi Dall, 1917, E. (A.) keratium Dall, 1919, E. strongi Bartsch, 1928, and E. (A.) slevini Strong & Hertlein, 1939, shows them all to have the following characteristics in common:, Ridges between the costae are evenly spaced and prominent, continuing in some cases on to the face of the slightly reflected costae. The anterior end of the lip has a strong, wrinkled fasciole behind the lip. The operculum is thin and paucispiral. The number of costae per whorl tends to be greater toward the southern end of the geographical range. This is a common intertidal species which may account for its synonymous names.


Distribution:

Baja California, Gulf of California south to Ecuador [DuShane 1974]


Habitat:

intertidal [DuShane, 1974] to 127m [Shasky, 1996:85]


Etymology:

Epitonium acapulcanum Dall, 1917 named for the location of the holotype, Epitonium slevini Strong & Hertlein, 1939 named for Joseph R. Slevin an American herpetologist who served over 50 years at the California Academy of Sciences, Epitonium xantusi Dall, 1917 named for location of the holotype Xantus [Cape San Lucas]


Type Material:

Holotype: Epitonium (Asperiscala) acapulcanum: USNM 59337, location: None given, but the name would suggest Acapulco, Mexico
Holotype: Epitonium (Asperiscala) xantusi: USNM 4107, location: Cabo San Lucas
Holotype: Epitonium (Asperiscala) keratium: USNM 217878, location: Isla Magdalena, outer coast of Baja California, Mexico
Holotype: Epitonium strongi: USNM 367967, location: Guayaquil, Ecuador
Holotype: Epitonium (Asperiscala) slevini:, location: CAS[GTC] 724 Taboga Island, Panama for Epitonium acapulcanum Dall, 1917. [DuShane, H., 1970]
Holotype: USNM 59337 [as Epitonium xantusi Dall, 1917; ~ Epitonium (Asperoscala) [sic;~ Asperiscala] keriatum Dall, 1919; ~ Epitonium strongi Bartsch, 1928; ~ Epitonium (Asperoscala) [sic;~ Asperiscala] slevini Strong & Hertlein, 1939.] - Locality: La Paz to Acapulco.. [Brown, L. & Neville, B.D., 2015]
Holotype: USNM 217878 [as Epitonium keratium Dall, 1919:] - Locality: Magdalena Bay, Lower California.. [Brown, L. & Neville, B.D., 2015]
Holotype: CAS[GTC] 724 [as Epitonium slevini Strong & Hertlein, 1939:] - Locality: off Taboga Island, Panama, dredged in 3 to 9 fms [= 5-16 m].. [Brown, L. & Neville, B.D., 2015]
Holotype: USNM 367967 [as Epitonium strongi Bartsch, 1928:] - Locality: Salinas, Guayaquil Bay, Guayaquil, Ecuador.. [Brown, L. & Neville, B.D., 2015]
Holotype: USNM 4107 [as Epitonium xantusi Dall, 1917:] - Locality: Cape San Lucas [DuShane 1974]. [Brown, L. & Neville, B.D., 2015]
Plesiotype No. 4775 (C. A. S.); Isthmus Bay, Espiritu Santo Island, Gulf of California. Plesiotype No. 4776 (C. A. S.); Cape SanLucas, Lower California. [as Asperiscala xantusi (Dall, 1917)]. [Baker, F.; Hanna, G D. & Strong, A. M., 1930]


SpeciesImage

DuShane, H. (1970). pp: 8. Fig. 1.

Figure 7: Epitonium (Asperiscala) acapulcanum Dall, 1917- Holotype, USNM 59337; length 5 mm; width 2 J mm X 13

Distribution

as listed in source literature

Dall, W. H. (1917).
Shown in text as Epitonium xantusi Dall, 1917
Species Image
Dall, W. H. (1917).
Species Image
pp: 475.
Baker, F.; Hanna, G D. & Strong, A. M. (1930).
Shown in text as Asperiscala xantusi (Dall, 1917)
Species Image
Plate 3. Fig. 1-3.
Fig. 1. Epitoniiim xavtusi Dall. Plesiotypc No. 4775 (C. A. S.); Isthmus Bay, Espiritu Santo Island, Gulf of California; length 4 mm.; diameter 1.9 mm.
Fig. 2. Epitonium xantusi Dall.
Plesiotype No. 4776 (C. A. S.); Cape SanLucas, Lower California; length 5.5 mm.; diameter 2.8 mm.;
Species Image
pp: 50.
Dushane, H. (1970).
Species Image
pp: 8. Fig. 1.
Figure 7: Epitonium (Asperiscala) acapulcanum Dall, 1917- Holotype, USNM 59337; length 5 mm; width 2 J mm X 13
Species Image
pp: 8. Fig. 2.
Figure 2: Epitonium (Asperiscala) xantusi Dall, 1917. Holotype, USNM 4107; length 5! mm; width 3mm X 11
Species Image
pp: 8. Fig. 3.
Figure 3: Epitonium (Asperoscala) keratium Dall, 1919. Holotype, USNM 217878; length 10 mm; width 4! mm X 6
Kaicher, S.D. (1983).
Shown in text as Epitonium keratium Dall, 1919
Species Image
Card #: EP3-3647.

Synonymy:

Asperiscala acapulcana Dall, 1917 [in Shasky, D.R., 1996].
Asperiscala xantusi (Dall, 1917) [in Baker, F.; Hanna, G D. & Strong, A. M., 1930].
Epitonium keratium Dall, 1919: [in Brown, L. & Neville, B.D., 2015].
Epitonium keratium Dall, 1919 [in Kaicher, S.D., 1983].
Epitonium slevini Strong & Hertlein, 1939: [in Brown, L. & Neville, B.D., 2015].
Epitonium strongi Bartsch, 1928: [in Brown, L. & Neville, B.D., 2015].
Epitonium xantusi Dall, 1917 [in Dall, W. H., 1917].
Epitonium xantusi Dall, 1917; ~ Epitonium (Asperoscala) [sic;~ Asperiscala] keriatum Dall, 1919; ~ Epitonium strongi Bartsch, 1928; ~ Epitonium (Asperoscala) [sic;~ Asperiscala] slevini Strong & Hertlein, 1939. [in Brown, L. & Neville, B.D., 2015].
Epitonium xantusi Dall, 1917: [in Brown, L. & Neville, B.D., 2015].


Source Literature:

Baker, F.; Hanna, G D. & Strong, A. M. (1930). Some Mollusca of the family Epitoniidae from the Gulf of California. 19(5). https://www.biodiversitylibrary.org/page/3148444
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. (1970). Two New Epitoniidae from the Galápagos Islands.. The Veliger. 12(3). https://www.biodiversitylibrary.org/page/42516564#page/460/mode/1up [Accessed 25 September 2023]
Kaicher, S.D. (1983). Epitoniidae III [Pack 35]. S. D. Kaicher, St. Petersburg, Florida. http://www.femorale.com/kaicher/species.asp?f=Epitoniidae&c=125 [Accessed 8 May 2023]
Shasky, D.R. (1996). Additional distributional records of interesting and rarely collected marine gastropods (Epitoniidae) from the tropical eastern Pacific. Festivus. 28(8). https://www.biodiversitylibrary.org/item/195791 [Accessed 14 November 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 [Accessed 8 November 2025]

WoRMS direct page link: Open WoRMS record