Pincerna costulosus Bavay & Dautzenberg, 1912

Sang, Do Duc & Son, Nguyen Thanh, 2022, The land snail genus Pincerna Preston, 1907 (Gastropoda: Alycaeidae) from Vietnam and Laos, with description of a new species, Raffles Bulletin of Zoology 70, pp. 364-375 : 365-369

Pincerna costulosus Bavay & Dautzenberg, 1912

( Figs. 1 , 2D, E , 6C ; Tables 1, 2)

Alycaeus costulosus Bavay & Dautzenberg, 1912: 49 , pl. 4, figs. 1–4 (type locality: Phong Th ổ, Lai Châu, Vietnam).

Pincerna costulosa – Páll-Gergely et al., 2017: 10, fig. 3F; 2020: 172; Chen & Wu, 2020: 45, figs. 1, 4C, D.

Types examined. Phong Tho, Tonkin, col. Messager, MNHN-IM-2000-31786 (syntypes) ( Fig. 2D ); Phong-Tho, col. Messager, No. 29, RBINS 525426 .

Additional material examined. ZMHU/ 4 ( Fig. 2E ), Vietnam, Lai Châu Province, Phong Th ổ District, Kh ổng Lào

Commune, limestone outcrops, 22°35′20″N, 103°23′52″E, 889 m above sea level (a.s.l.), col. D.S. Do & V. T. Sin, 14 July 2015 .

Diagnosis. Pincerna costulosus is characterised by a small sized, translucent, high conical shell with strongly, regularly ribs on R1, and R2 extremely short.

Distribution. Pincerna costulosus is known from northwestern Vietnam (Lai Châu Province) and Southwest China (Yunnan Province) ( Chen & Wu, 2020).

Remarks. The species is quite stable in terms of shell characters, although only a few shells are known. Pincerna costulosus has been recently recorded from Xishuangbanna, Yunnan Province, China ( Chen & Wu, 2020). The present record extends the distributed range circa 400 km to the west.

Figures

Fig. 1. Distribution of Pincerna species in Vietnam and Laos. Triangle: Pincerna anceyi; Grey circle: Pincerna costulosus; Black circles: Pincerna mouhoti; Squares: Pincerna vanbuensis; Star: Pincerna clausa, new species. The localities are detailed in Table 1.

Fig. 2. Shells (apertural view, dorsal view, ventral view, and side view) of Pincerna species. A, Pincerna anceyi (Mabille, 1887), syntype MNHN-IM-2000-31797; B, C, Pincerna mouhoti (L. Pfeiffer, 1862): B, specimen from MƯờng La, SƠn La, Vietnam, ZMHU; C, syntype NHMUK 20170120; D, E, Pincerna costulosus Bavay & Dautzenberg, 1912: D, syntype MNHN-IM-2000-31786; E, specimen from Phong Thổ, Lai Châu, Vietnam, ZMHU.

Fig. 6. Synoptic view of Vietnamese and Laos Pincerna species. A, MNHN-IM-2000-31797; B, NHMUK 20170120; C, MNHN- IM-2000-31786; D, VNMN-IZ 002.304; E, MNHN-IM-2000-31798.