Pincerna (?) anceyi ( Mabille, 1887 ), 1907

Páll-Gergely, Barna, 2023, Revision of the Alycaeidae of China, Laos and Vietnam (Gastropoda: Cyclophoroidea) II: The genera Alycaeus and Pincerna, Zootaxa 5249 (2), pp. 253-276 : 262-263

Pincerna (?) anceyi ( Mabille, 1887)

( Fig. 7 )

Alycaeus anceyi Mabille, 1887: 151–152 , pl. 3, figs 14–15.

Alycaeus (Alycaeus) anceyi — Kobelt, 1902: 341.

Alycaeus anceyi —Páll-Gergely et al., 2017: 10: fig. 3E.

Pincerna (?) anceyi — Páll-Gergely et al., 2020: 170 .

Type material. Tonkin, coll. Mabille, MNHN-IM-2000-31797 (3 syntypes, Fig. 7 ) .

Diagnosis. A medium-sized alycaeid species with a shell that is slightly higher than wide, R1 glossy, R2 relatively short and smooth, R3 smooth with a blunt swelling.

Description. Shell slightly higher than wide; greyish with whitish peristome; protoconch rather glossy, consists of 1.75 whorls; R1 glossy, nearly smooth, with some very weak, irregular radial and spiral lines, consists of 1.75 whorls; R2 and R3 slightly shorter than quarter whorl combined, R3 being at least twice longer than R2; R2 with approx. 28 microtunnels (slender, whitish lines), it is smooth from above, tube short but elongated; R3 smooth with a blunt swelling, glossy; constriction between R2 and R3 moderately deep; aperture conspicuously large; peristome white, outer peristome expanded and reflected; inner peristome slightly protruding; boundary between two peristomes clearly visible; umbilicus slit-like, open.

Measurements (in mm). D = 4.6, H = 4.8 (syntype).

Operculum. The outer surface of the operculum of the holotype could be examined: it is horny, multispiral, without elevated lamella.

Variation in specimens. Only the syntypes are known.

Differential diagnosis. Alycaeus vanbuensis Bavay & Dautzenberg, 1900 is similar, but usually larger, and its R1 is ribbed.

Distribution. This species is known from the type sample only.

Remarks. The shell shape is similar to that of Pincerna , but there are no strong ribs in the upper whorls, and the tube is elongated, not extremely short and piriform. The tube is short for the genus Alycaeus , but the shell shape agrees with other members of the genus.

Figures

FIGURE 7. Pincerna anceyi (Mabille, 1887) (syntype, MNHN-IM-2000-31797).