Pupina thaitranbaii Do, 2017

Sang, Do Duc, 2017, Two new species of the genus Pupina (Caenogastropoda: Pupinidae) from Northwestern Vietnam, Raffles Bulletin of Zoology 65, pp. 299-303 : 302-303

Pupina thaitranbaii Do , new species

( Figs. 1 , 2B , 3B ; Table 2)

Pupina sp.2 – Do et al., 2015: 126, fig. 6E.

Type specimens. Holotype: 1 ex. (SH 10.2 mm, SW 5.3 mm) ( HNUE-OC 00109 ), limestone forest in Pa Cop Village , Van Ho Commune, Van Ho District, Son La Province, Vietnam

(20°45′56″N, 104°44′30″E; elevation 1,013 m), coll. Do Duc Sang & Vu Thu Phuong, 26 October 2013. Paratypes: 6 ex. ( SORC 1048 ), same data as holotype .

Etymology. The new species is dedicated to Professor Thai Tran Bai, of the Hanoi National University of Education, who has continuously supported terrestrial snail research in Vietnam.

Diagnosis. Anterior canal appears as a slit on the side, forming a long gutter, and extends into a spike-like protrusion. Parietal side of peristome thickened, with a prominent keeled edge. Umbilicus open and deep.

Description. Shell small (SH 9.9–10.2 mm), elongate-ovate, brownish yellow to glassy-white. Apex obtuse. Shell surface sculptured with rather regular radial striae, which are slightly oblique, distinct, thin, densely placed, and usually slightly more widely spaced on the last whorl. Whorls 6–6¼, early whorls slightly convex, last whorl large about two-thirds of shell height and relatively convex in front. Spire somewhat extended and convex. Sutures shallowly impressed. Aperture circular, the parietal side with a low ridge, which merges into the parietal tooth. Outer lip thickened and broadly expanded. Parietal callus white, sharply defined and thickened. Peristome simple, thickened, somewhat reflexed, and interrupted by two canals. Posterior canal continues vertically upward and forming narrow groove, bordered by thickened lip and parietal tooth. Anterior canal appearing as a slit on the side, forming a long gutter that terminates as a spike-like process. Parietal tooth well-developed, whitish and triangular shape. Umbilicus open and deep.

Distribution. The new species is thus far known only from the limestone forest in Pa Cop Village, Van Ho Commune, Van Ho District, Son La Province, Vietnam.

Remarks. The unique and prominent spike-like protrusion at the anterior canal is most diagnostic in distinguishing P. thaitranbaii sp. n. from other congeneric species in Vietnam. Operculum unknown.

Figures

Fig. 1. Approximate geographic positions of the type localities of Pupina species of Vietnam. The numbers correspond to the species list in Table 1.

Fig. 2. Shells of Pupina spp.: A, Pupina sonlaensis n. sp. (holotype HNUE-OC 00108); B, Pupina thaitranbaii, n. sp. (holotype, HNUE-OC 00109); C, Pupina tonkiana Bavay & Dautzenberg, 1899 (HNUE-OC 00106).

Fig. 3. Close-up views of the apertures of the different species: A, Pupina sonlaensis n. sp. (holotype HNUE-OC 00108); B, Pupina thaitranbaii, n. sp. (holotype, HNUE-OC 00109); C, Pupina tonkiana (HNUE-OC 00106).