Pincerna anceyi ( Mabille, 1887 )

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

Pincerna anceyi ( Mabille, 1887)

( Figs. 1 , 2A , 6A ; Tables 1, 2)

Alycaeus anceyi Mabille, 1887: 151 , pl. 3, figs. 14, 15 (type locality:

Tonkin Vietnam). Alycaeus (Orthalycaeus) anceyi – Kobelt & Möllendorff, 1897: 147. Alycaeus (Alycaeus) anceyi – Kobelt, 1902: 341. Alycaeus anceyi – Fischer, 1891: 108; Fischer & Dautzenberg,

1904: 432; Páll-Gergely et al., 2017: 10, fig. 3E. Pincerna anceyi – Páll-Gergely et al., 2020: 170.

Types examined. Tonkin, col. Balansa, 1887, MNHN- IM-2000-31797/ 3 (syntypes) ( Figs. 2A , 6A ) .

Diagnosis. Pincerna anceyi is characterised by a mediumsized, globose shell with R1 nearly smooth, some fine ribbing near suture; R2 short, with very weak and regularly spaced stripes.

Distribution. Pincerna anceyi is known from northern Vietnam (Quảng Ninh Province) ( Fischer & Dautzenberg, 1904).

Remarks. In comparison with other congeners from Vietnam and Laos, P. anceyi can be identified by its smooth shell surface and spiral striation not visible on R1. Fischer & Dautzenberg (1904) recorded this species from “Ile Ké-bao, golfe du Tonkin ” (most probably refers to Cái Bầu Island, Vân Đồn District, Quảng Ninh Province) and other species of the Alycaeidae from northern Vietnam ( Dioryx compactus , Dicharax fracterculus , Alycaeus gibbus , Metalycaeus heudei , Dioryx major , Dioryx messageri , Dioryx pilula , Dioryx requiescens , Pincerna vanbuensis ), Laos ( Dioryx bacca , Dioryx cariniger , Pincerna mouhoti ) and Thailand ( Chamalycaeus canaliculatus , Metalycaeus distinctus , Stomacosmethis roebeleni ). This species is probably endemic to northern Vietnam.

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.