10. Serina vincentii (Gredler, 1898)

Figs. 1, 5 L; Tables 1, 3

Buliminus (Napaeus) vincentii Grelder, 1898a: 5, T. F. 1. Napaeus vincentii— Grelder, 1898b: 104.

Buliminus (Serina) vincentii— Möllendorff, 1901: 357.

Buliminus (Ena) vincentii— Kobelt, 1902: 717, pl. 106, fig. 6. Turanena vincentii— Yen, 1939: 86, pl. 8, fig. 12; Zilch, 1974: 216. Serina vincentii— Chen, Zhou, Luo & Zhang, 2003: 442.

Type locality. Between Tshundshiawa & Wangjiaba (=Wangjiaba, 33°6ʹN, 105°12ʹE, Wenxian, Gansu; Tshundshia-wan is a error of “Tshun-dshia-wa”, see Gredler, 1898a: p. 6).

Material examined. SMF-42032: 3 fms from the type locality.

Distribution. Gansu (type locality).

Diagnosis. Shell with the most swollen part occurred at body whorl. Shell with or without a narrow, defined zone below the suture. Last whorl gradually ascending towards aperture; rounded at periphery. Aperture completely attached to body whorl; not armed; not duplicate.

Shell. Conic; with apex not abruptly pointed; dextral; with the most swollen part occurred at body whorl; height 8.0–8.6–8.9, diameter major 5.0–5.1–5.3, ratio of height /diameter major 1.61–1.66–1.69. Growth lines fine and clear. Whorls 6 7/8–7 1/8–7 1/2, convex; with or without a narrow, defined zone below the suture. Embryonic shell 1 1/2-1 1/2-1 1/2 whorls. Postnuclear whorls smooth. Last whorl gradually ascending towards aperture; rounded at periphery; without smoothed spiral peripheral depression or rugate region. Aperture in a plane and straight; circular; oblique; completely attached to body whorl; height 3.5–3.7–3.9, width 3.5–3.6–3.7, ratio of shell height / apertural height 2.30–2.30–2.50. Aperture not duplicate. Peristome and parietal callus almost completely fusing except for a channel at upper insertion of peristome. Reflexed part of peristome straight and not curved backward. Parietal callus distinct. Columellar margin reflexed. Columella arched. Umbilicus widely open. Shell uniformly dark chestnut. Aperture white or brownish white. Measured specimens: SMF-42032: 3 shells.