The land snail genus Pincerna Preston, 1907 (Gastropoda: Alycaeidae) from Vietnam and Laos, with description of a new species Author Sang, Do Duc Author Son, Nguyen Thanh text Raffles Bulletin of Zoology 2022 2022-06-01 70 364 375 journal article 10.26107/RBZ-2022-0018 2345-7600 7174164 E3A5AA23-BEAE-445E-981F-93A9E7A79417 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 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. 3. Shells (apertural view, dorsal view, ventral view, and side view) and operculum (outer surface, inner surface, and side view) of Pincerna vanbuensis (Bavay & Dautzenberg, 1900) . A, syntype MNHN-IM-2000-31798; B, E, specimen from Thuận Châu, SƠn La, Vietnam, ZMHU; C, specimen from Khoune, Xieng Khouang, Laos, ZMHU; D, specimen from Xiengkho, Houaphanh, Laos, ZMHU. 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.