Published August 11, 2020 | Version v1
Taxonomic treatment Open

Caecum adamsi subsp. nomen

Description

Caecum adamsi nomen novum

Figures 105 A–G, 106A–F, 107A–B, 126A

Elephantanellum carpenteri Bartsch, 1920: 567, holotype USNM 340727, San Diego, California. [non Deshayes, 1861 †]. Elephantanellum carpenteri — Keen, 1971: 398.

Caecum (Elephantulum) carpenteri —Abbott, 1974: 92, fig. 882.

Elephantulum carpenteri — Skoglund, 1992: 29.

non Brochina carpenteri — Lightfoot, 1993b: 82, fig. 30.

Caecum carpenteri — Raines, 2019: 101, fig. 3C.

Material examined. In addition to the type material the following lots were examined. SBMNH: SBMNH 115808, Bahia La Choya, Sonora, Mexico, intertidal, 1 sh; SBMNH 620157, Puerto San Carlos, Bahia Magdalena, Baja California Sur, Mexico, 2–10 m, 15 sh; SBMNH 621392, Estero Morua, Sonora, Mexico, intertidal, 4 sh; SBMNH 622342, Punta Tormenta, Sonora, Mexico, intertidal, 1 sh.

Original diagnosis. “This is a large thin shell, in which the segments of all stages are marked by very fine spiral sculpture and a little stronger incremental lines, while the last portion of these stages bears well developed annuli. These increase in number in succeeding stages.” Bartsch (1920: 567).

Description. Protoconch and teleoconchs I, II, III unknown. Teleoconch IV smooth with weak axial growth lines, axial rings developing near aperture (Fig. 106A, C), transition to teleoconch V marked by suture (Fig. 107A). Teleoconch V sculptured with weak axial growth lines and weak, longitudinal striae (Figs. 106B, D), transition to teleoconch VI marked by suture (Fig. 107A). Teleoconch VI (last growth stage) large for genus [Tol 4.57–4.80 mm], tubular, thin, fragile, moderately to strongly and regularly arched [Larc: 2.12–2.18 mm; Arc: 0.40–0.41 mm], subcylindrical, semi-translucent white (Figs. 105 A–B). Surface sculptured with longitudinal striae crossed by axial threads, which become raised annuli toward apertural end (Figs. 106 E–F). Posterior [Dpe: 0.76–0.80 mm] with rather thin edge, squared shoulder (Fig. 105D). Septum slightly inflated (Fig. 105G). Mucro not visible. Aperture [Da: 0.80–0.85 mm] thin (Fig. 105D). No varix. Lip smooth (Fig. 105D). Periostracum thin, smooth, yellowish (Fig. 105A). Operculum thin, light brown; exterior surface with 7–9 concentric rings (Fig. 105E). Conceptual reconstruction of growth stages shown in Fig. 107A.

Etymology. The replacement name honors Charles B. Adams, who described the first caecids from the eastern Pacific region.

Distribution and Habitat. From Santa Monica, Los Angeles County, California south to the Gulf of California, Mexico. Intertidal to 18 m. Uncommon to rare on sandy substrates.

Remarks. Caecum carpenteri (Bartsch, 1920) described in the original combination of Elephantulum carpenteri Bartsch, 1920 is a secondary homonym of, and preoccupied by Caecum carpenteri Deshayes, 1861 †. As there are no known synonyms of Bartsch’s species, Caecum adamsi nomen novum is here introduced for Caecum carpenteri (Bartsch, 1920).

Caecum adamsi is quite fragile and for many years had only been known from its holotype (USNM 340727, Fig. 105G). It also has a more restricted range than had been suggested by both Keen (1971) and Lightfoot (1993b). Lastly, it should be noted there is an error in Bartsch’s original type number. The catalog number for the holotype is USNM 340727, not 340726. The latter number is for the holotype of Caecum diegense Bartsch, 1920, which has been missing since the 1960s.

Notes

Published as part of Raines, Bret K., 2020, A Rosetta Stone for eastern Pacific Caecidae (Gastropoda: Caenogastropoda), pp. 1-146 in Zootaxa 4827 (1) on pages 124-125, DOI: 10.11646/zootaxa.4827.1.1, http://zenodo.org/record/4402308

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Linked records

Additional details

Biodiversity

Collection code
SBMNH
Family
Caecidae
Genus
Caecum
Kingdom
Animalia
Material sample ID
SBMNH 115808 , SBMNH 620157 , SBMNH 621392 , SBMNH 622342
Order
Littorinimorpha
Phylum
Mollusca
Species
nomen
Taxon rank
subSpecies

References

  • Bartsch, P. (1920) The Caecidae and other marine mollusks from the northwest coast of America. Journal of the Washington Academy of Sciences, 10, 565 - 572. https: // doi. org / 10.5962 / bhl. part. 3611
  • Deshayes, G. P. (1861) Caecum. In: Description des Animaux sans vertebres decouverts dans le bassin de Paris pour servir de supplement a la description des coquilles fossiles des environs de Paris, comprenant une revue generale de toutes les especes actuellement connues, Paris, 2, 299 - 303. https: // doi. org / 10.5962 / bhl. title. 51674
  • Keen, A. M. (1971) Sea shells of tropical West America. Second Edition. Stanford University Press, Stanford, California, xiv + 1064 pp.
  • Skoglund, C. (1992) Additions to the Panamic province gastropod (Mollusca) literature 1971 to 1992. Supplement. The Festivus, 24, 1 - 169. https: // doi. org / 10.5962 / bhl. title. 129425
  • Lightfoot, J. (1993 b) Caecidae of the Panamic Province. Part II. Of Sea & Shore, 16, 75 - 87.
  • Raines, B. K. (2019) Caecidae of the northeast Pacific (Gastropoda: Caenogastropoda). Zoosymposia, 13, 97 - 103. https: // doi. org / 10.11646 / zoosymposia. 13.1.10