Clostophis sankeyi Benson, 1860

Páll-Gergely, Barna, Hunyadi, András, Grego, Jozef, Reischütz, Alexander, Buczkó, Krisztina & Vermeulen, Jaap J., 2020, Clostophis Benson, 1860, is not a monotypic diplommatinid but a speciose hypselostomatid (Gastropoda: Eupulmonata), with descriptions of six new species, Raffles Bulletin of Zoology 68, pp. 350-368 : 352

Clostophis sankeyi Benson, 1860

( Fig. 3A )

Clostophis sankeyi Benson, 1860: 95 .

Clostophis sankeyi — Kobelt, 1902: 484.

Clostophis sankeyi — Egorov, 2013: 24.

Type locality. “Prope Moulmein, ad cavernas “Farm Caves” dictas” [Farm Caves at 16°32′N 97°42.8′E].

Types examined. Holotype of Clostophis sankeyi ( UMZCI.103320). Benson (1860) mentioned in the original description that only a single shell was available.

Additional material examined. 1 shell (coll. HA), Myanmar, Mon Province , Mawlamyine centre NEE ca. 26 km, Dhammasa Cave, 8 m a.s.l., 16°30.403′N, 97°48.646′E (locality codes 2018/49a and 20181011A), coll. A. Hunyadi, K. Okubo & J.U. Otani, 11 October 2018 ; 1 shell (coll. HA), Myanmar, Mon Province , Mawlamyine NE ca. 14 km, Kalagon, Kha Yone Cave, 0 m a.s.l., 16°31.986′N, 97°42.910′E (locality codes: 2018/50 and 20181011B), coll. A. Hunyadi, K. Okubo & J.U. Otani, 11 October 2018 .

Diagnosis. A Clostophis species with detached and descending last quarter of the body whorl, a comparatively narrow umbilicus, and a weak parietal tooth.

Description. Shell conical, upper whorls growing regularly, and seemingly are sunken into the last whorl, i.e., last whorl coils around penultimate whorl more apically in position than it would be expected from the growth rate of initial whorls. Whorls rounded, showing a very slight indication of a blunt shoulder. Tuba (i.e., last quarter whorl) strongly detached from penultimate whorl. Protoconch consisting of 1.5 whorls, pitted and spirally striated. Entire shell with 4.5 whorls. Umbilicus oval doe to the irregularly formed body whorl; occupies ca. one third of the shell width. Entire teleoconch with strong, elevated, rather equidistant spiral striae, and some weak, irregular radial growth lines. Some growth lines close to the suture on dorsal surface strong, almost rib-like. Aperture suboval. Sinulus wide. Parietal tooth weak and relatively short. Peristome expanded but not reflected.

Remarks. See under C. proboscideus .

Figures

Fig. 3. Shells of Clostophis species. A, holotype of Clostophis sankeyi (UMZCI.103320, copyright: The Trustees of the Natural History Museum, photo: Harry Taylor); B, holotype of Clostophis proboscideus (from the original description).