Gudeodiscus Páll-Gergely 2013

Shell very small to small, light brown to chocolate brown, with slightly elevated spire, consists of 5.25–5.5 whorls; suture relatively shallow, especially at the first 3–4 whorls; protoconch (2.25–2.5 whorls) glossy, very finely, regularly ribbed, but the ribs are sometimes hardly visible, they are more prominent at the upper part of the whorls, close to the suture; teleoconch without notable spiral lines, very finely regularly ribbed; sculpture strength equal on ventral and dorsal side; umbilicus narrow and deep; aperture with widened upper part (sinulus), apertural lip whitish, thin, slightly expanded but not reflexed; apertural denticle (fold) always present, very small, free from the callus or connected to it. Two specimens were opened. Parietal side with a stronger anterior lamella with anteriorly widened lower part, and a slimmer posterior lamella; shorter upper and longer lower horizontal plicae free from the anterior lamella, the lower one a bit extends beyond the anterior lamella in the anterior direction. Palatal side with six plicae; first and last are straight, the others are depressed Z-shaped and are connected with a ridge.

The type specimens of Plectopylis infralevis and Plectopylis soror (synonym of infralevis) were collected in Quang Huyen (Quảng Uyên) (see Figure 39).

(see Figure 41). Examined material was from only Cao Bằng and Lạng Sơn Provinces. The type locality (Quang-Huyen) lies in Cao Bằng Province (see Figure 39).

(see Figure 40): We have newly-collected material only from Bắc Kạn Province. The species was previously recorded from That Khé (Lạng Sơn Province) and Nac Ri (Hà Giang Province) (Gude 1901a, see also Figure 39).

(see Figure 41): The species was described from “Muong-Kong” (=Mường Khương, Lào Cai Province; see Figure 39). Material is noted from northeast of this locality, from northern Hà Giang Province and eastern parts of Yunnan Province (China) (see Páll-Gergely and Hunyadi 2013).

(see Figure 42): Newly-collected material from Cao Bằng and Bắc Kạn Provinces was examined. There is a single shell which is identical to the holotype of Plectopylis lepida and is labelled as being collected from Hạ Long Bay, but this collection locality is probably incorrect.

(see Figure 43). The new species is known from few locations in south-eastern Sơn La province.