Clostophis thinbowguensis, Páll-Gergely & Hunyadi, 2022

Páll-Gergely, Barna & Hunyadi, András, 2022, New and little-known species of Clostophis Benson, 1860 from Southeast Asia (Gastropoda: Eupulmonata: Hypselostomatidae), Raffles Bulletin of Zoology 70, pp. 417-439 : 427

Clostophis thinbowguensis , new species

( Fig. 9 )

Type material. Holotype (SH: 1.27 mm, SW: 1.25 mm) (MNHN-IM-2000-38057), Myanmar, Tanintharyi Region, Thin Bow Gu Cave, Phayahran Camp ; 11°11.38′N, 99°10.30′E; coll. F. Bréhier, 20 February 2015.

Diagnosis. Among species of Clostophis with the last part of the penultimate whorl attached to the penultimate whorl, C. thinbowguensis , new species, differs by the incurved last part of the last whorl, in combination with the presence of a single tooth (a parietalis) in the aperture.

Description. Shell conical, width and height equal or almost equal. Whorls rounded. Last whorl not detached from penultimate whorl, although aperture slightly protruding (parietal callus elevated from penultimate whorl). Protoconch consisting of slightly less than 1.5 whorls, its sculpture is not discernible due to corrosion of shell surface. Entire shell with 4.75 whorls. Umbilicus normally wide, ca. one third of shell width. Entire teleoconch corroded, except for the characteristic presence of dense spiral striation on the apertural and ventral side of the body whorl (counting them is not possible). Some weak, irregular radial growth lines are present. Aperture subcircular, sinulus wide and weakly isolated due to low, deeply situated parietal tooth. No additional apertural barriers present. Peristome slightly expanded, not reflected.

Measurements (in mm). SH = 1.27, SW = 1.25 (holotype).

Differential diagnosis. Clostophis thinbowguensis , new species, is similar to some Angustopila species, but differs from them by the generally larger size and the denser spiral striation. The most similar species is probably Angustopila concava due to the similar strongly oblique aperture, but that species is smaller, has a concave conical shell, and a more anteriorly situated lower parietal tooth.

Etymology. This new species is named after its type locality (Thin Bow Gu Cave).

Figures

Fig. 9. Clostophis thinbowguensis, new species (holotype, MNHN-IM-2000-38057).