Gudeodiscus (Veludiscus) emigrans quadrilamellatus Pall-Gergely , 2013

Pall-Gergely, Barna, Hunyadi, Andras, Ablett, Jonathan, Lương, Hao Văn, Fred Naggs, & Asami, Takahiro, 2015, Systematics of the family Plectopylidae in Vietnam with additional information on Chinese taxa (Gastropoda, Pulmonata, Stylommatophora), ZooKeys 473, pp. 1-118 : 44

Taxon classification Animalia Stylommatophora Plectopylidae

Gudeodiscus (Veludiscus) emigrans quadrilamellatus Pall-Gergely, 2013 Figures 6F, 13 C–D

Plectopylis emigrans Gude 1901a, Journal de Conchyliologie, 49: 206-208. Plate 6., Figs 5 a–c. ["Bac Kan, secteur de Nac Ri, Baie d’Along”].

Gudeodiscus emigrans quadrilamellatus Páll-Gergely in Páll-Gergely & Hunyadi 2013, Archiv für Molluskenkunde, 142 (1): 15-17., Figs 27, 45 a–b, 58 (map).

Material examined.

Samples not mentioned in Páll-Gergely and Hunyadi (2013) are the following: Hạ Long Bay, leg. Messager, MNHN-IM-2012-2320/1; Indochine, leg. Messager, MNHN-IM-2012-2455/2; Tonkin, coll. Letellier 1949, MNHN-IM-2012-2448/1.

Diagnosis.

Spiral sculpture conspicuous, parietal wall with one lamella and four parallel horizontal plicae in front of the single lamella.

Measurements

(in mm): D = 17.7-18.6, H = 7.1-7.6 (n=3, sample from the type locality).

Differential diagnosis.

See under Gudeodiscus emigrans emigrans .

Intrasubpecific diversity.

Low; shell characters are stable. The subspecies is easily recognisable and can be separated from other Vietnamese and Chinese taxa without problems.

Distribution

(see Figure 42): Gudeodiscus emigrans quadrilamellatus is known from Bắc Kạn and Tuyên Quang Provinces. Museum samples are labelled from Tam Đảo, on the border region of Thái Nguyên and Vĩnh Phúc Provinces (Au Nord de Ha Noi, Tam Dao, MNHN-IM-2012-2123/3). Records from the Hạ Long area (e.g. Gude 1901a) are probably incorrect (see also Páll-Gergely and Hunyadi 2013).