8. Pupinidius nanpingensis ambigua (Moellendorff, 1901)

Figs 1, 3 E–F

Buliminus (Pupinidius) nanpingensis ambigua Moellendorff, 1901: 347, pl. 14, figs 18, 19; Kobelt, 1902: 850. Pupinidius nanpingensis ambigua Yen, 1939: 84, pl. 8, fig. 2.

Material examined. SMF-41996: Lectotype. Nan-ping, Kansu, China. Slg. Moellendorff. SMF-41997: Paratypes. 3 fmss. Nan-ping, Kansu, China. Slg. Moellendorff.

Distribution. Sichuan (type locality).

Type locality. Nanping (Sichuan).

Diagnosis. Shell bandless; not striate. Aperture with or without angular tubercle. Most swollen part at body whorl. With 6.000–6.125 whorls; height 17.2–20.1, diam. maj. 9.5–10.7.

Re-description of shell. Bullet-shaped; apex slightly protruded. Most swollen part at body whorl. Shell dextral; thin; solid; opaque; glossy; not speckled; not spirally grooved; with 6.000–6.063–6.125 whorls. Whorls not shouldered; flattened. Growth lines usually not very clear. Embryonic shell smooth; polished. Embryonic shell with 1.375–1.500–1.625 whorls. Postnuclear whorls smooth. Suture normal, without narrow defined zone on beneath whorl. Last whorl gradually ascending towards aperture, or straight in front (in one paratype); rounded at periphery; without smoothed spiral peripheral depression nor rugate region. Shell 17.2–18.4–20.1 high; 9.5–10.0– 10.7 in diam. maj. Height/width ratio 1.81–1.84–1.89. Aperture in a plane; completely attached to body whorl; truncate-ovate; not adnate; oblique; not armed; with angular tubercle, or without angular tubercle; 8.4–8.8–9.7 high; 6.5–6.8–7.2 wide. Ratio of shell height to aperture height 2.05–2.09–2.13. Peristome reflexed with distinct cuff. Cuff made by the reflexed peristome straight and not curved backward. Peristome expanded; sharp. Parietal callus indistinct. Columellar margin reflexed. Columella vertical (or even bending axially). Outer edge of columellar lip vertical. Umbilicus narrowly open. Shell uniformly coloured in redish brown. Aperture brownish white.