Epitoniidae Berry, 1910 (1812)

Amaea contexta

DuShane, 1970

Description:

Dimensions range from 15.4 mm - 15.4 mm high and 4.5 mm wide.
Width to height ratio: 0.29:1 ~ 0.29:1

Shell: slender, acuminate; small. Exterior colour dark brown. About 14 whorls, convex; protoconch with ~4 whorls smooth, white, glassy; teleoconch with 10 whorls dark brown, convex. Suture deeply impressed. Imperforate. Approximately 24 costae on the body whorl. Costae are thin, strong, occasionally with a very heavy rib. There is a single varix on each whorl. The varix is prominent, heavy. Intercostal spaces with spiral sculpture, creating a beaded appearance when crossing the costae. Interstices with approximately 18 spiral striae per whorl. Base with basal ridge. Aperture oval; outer lip formed by the extension of the final varix. Operculum absent in the holotype.

As discussed by Dushane [1974], no other epitoniid from the west American coast is related to this species. Sculpture is unique, making the generic allocation uncertain. Since the general features suggest Amaea H. and A. Adams, 1853, it is placed here provisionally.

Distribution:

According to Dushane [1974: 52], this species is restricted to a small area off the west Mexican coast from Manzanillo, Colima to Petatlan Bay, Guerrero, Mexico

Habitat:

dredged, 9-18m

Etymology:

Latin, contextus = interwoven, a reference to the woven texture of the axial and spiral sculpture.

Type Material:

Holotype; LACM 1199. for Amaea contexta DuShane, 1970 - Type Locality: Petatlan Bay, Guerrero, Mexico, 17° 31' 45' N, 101° 27' 34' W, 5-10 fms, hard sand and shell bottom, R/V Velero III station 265-34, 3 February 1934, one specimen.. [DuShane, H., 1970a]
Holotype: LACM 1199 [as Amaea (s.l.) contexta DuShane, 1970:] - Type Locality: R/V VELERO III station 265-34, Petatlan Bay, Guerrero, Mexico, 17° 31' 45''N, 101° 27' 34''W, 5-10 fms [= 9-18 m], hard sand and shell bottom.. [Brown, L. & Neville, B.D., 2015]
HOLOTYPE: LACM 1199 (dry) for Amaea contexta DuShane, 1970 - Type Locality: 9-18 m, Bahía Petatlán, Guerrero, México (17 31.7 N, 101 27.57 W), Leg.: R/V Velero III, 03 MAR 1934.. [Groves, L.T., 2012]

SpeciesImage

DuShane, H. (1970a). pp: 4. Fig. 5.

Holotype: Petatlan Bay, Guerrero, Mexico, 15.4 x 4.5mm

Distribution

as listed in source literature

DuShane, H. (1970a).

Species Image

pp: 4. Fig. 5.

Holotype: Petatlan Bay, Guerrero, Mexico, 15.4 x 4.5mm

Species Image

pp: 5-6.

DuShane, H. (1974).

Species Image

pp: 38. Fig. 69.

Figure 69: Amaea (s. I.) contexta DuShane, 1970. Holotype, LA CM 1 199; length 15.4mm; width 4^ mm X4

Synonymy:

Amaea (s.l.) contexta DuShane, 1970: [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]
DuShane, H. (1970a). Five New Epitoniid Gastropods from the West Coast of the Americas. Los Angeles County Museum Contributions in Science. 185. https://www.biodiversitylibrary.org/page/52108947#page/221/mode/1up [Accessed 25 September 2023]
DuShane, H. (1974). The Panamic-Galapagan Epitoniidae. The Veliger. 16 (Sup. 14). https://www.biodiversitylibrary.org/page/42500298 [Accessed 25 September 2023]
Groves, L.T. (2012). Catalog of Recent Molluscan Types in the Natural History Museum of Los Angeles County. Natural History Museum of Los Angels County, Malacology Section. https://www.academia.edu/77579686/Catalog_of_Recent_Molluscan_Types_in_the_Natural_History_Museum_of_Los_Angeles_County [Accessed 8 August 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