Clostophis bactrianus, 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 : 423-427

Clostophis bactrianus , new species

( Fig. 8 )

Type material. Holotype (SH: 1.1 mm, SW: 1.6 mm) ( HNHM 105324 ), Pahang, Gua Bama, 9 km from Kuala Lipis toward Padang Tungku , 120 m a.s.l., 4°11.652′N, 101°57.936′E (locality code: 2013/28), coll. A. Hunyadi, 19 January 2013 . Paratypes: 24 shells (coll. HA), same data as for holotype.

Diagnosis. Uniquely characterised within the genus by the two low, blunt teeth on the columellar and basal side of the aperture.

Description. Shell conical, wider than high, apex blunt. Whorls rounded or slightly shouldered. Last whorl not detached from penultimate whorl, although aperture may be slightly protruding (parietal callus elevated from penultimate whorl). Protoconch consisting of 1.5 whorls, spirally striated except for the first ca. 0.25 whorl. Entire shell with 4.25 whorls. Umbilicus relatively narrow, less than one third of shell width. Entire teleoconch with strong, elevated, rather equidistant spiral striae (ca. 20–22 on body whorl in apertural view), and some weak, irregular radial growth lines. Aperture almost heart-shaped due to large sinulus. Parietal tooth pronounced, relatively short, reaches peristome. Palatal tooth also strong, elevated, but blunt. Sinulus clearly separated from rest of aperture due to strong parietal and palatal teeth. Two low, blunt denticles situated next to each other on the peristome on the basal and columellar sides of the aperture; the lower one is situated slightly left (i.e., direction of the columella) from the basal most point, whereas the upper one sits on the columellar side.

Measurements (in mm). SH = 0.94–1.05, SW = 1.03–1.06 (n = 4).

Differential diagnosis. Clostophis bactrianus , new species, differs from C. neglectus by the smaller shell size, the more elevated parietal tooth, the more basally-situated palatal tooth (and as a result, a larger sinulus), and the two low denticles on the columellar and basal sides of the aperture. Clostophis laidlawi has five apertural barriers.

Etymology. The specific epithet derives from the scientific name of the Bactrian camel ( Camelus bactrianus Linnaeus, 1758 ). The two blunt columellar teeth of this new species resemble the two humps on the camel’s back.

Figures

Fig. 8. Clostophis bactrianus, new species (holotype, HNHM 105324).