Chersaecia woodthorpei (Gude, 1899)

Páll-Gergely, Barna, 2018, Systematic revision of the Plectopylinae (Gastropoda, Pulmonata, Plectopylidae), European Journal of Taxonomy 455, pp. 1-114 : 67-68

Chersaecia woodthorpei (Gude, 1899) comb. nov.

Figs 24M–N, 30C

Plectopylis woodthorpei Gude, 1899b: 15–16 , fig. 98a–g [“Fort Stedman, Burma ”].

Plectopylis (Plectopylis) woodthorpei – Gude 1899d: 148; 1899e: 175; 1914b: 124–126, fig. 61a–h. Plectopylis (Chersaecia) woodthorpei – Gude 1920: 61.

Diagnosis

A very small, sinistral species with an angulated body whorl and a very slightly elevated spire; parietal wall with two lamellae, a main and an intermediate parietal plicae, both of which are in contact with the anterior lamella; palatal wall with an overall Plectopylis -like palatal plication, with three additional horizontal plicae anterior to the vertical plate, which is formed by the fourth and fifth plicae.

Material examined

Syntypes

MYANMAR: 3 shells, Burmah, Fort Stedman, Woodthorpe leg. ( NHMUK 1903.7.1.2100).

Additional material

MYANMAR: 6 shells, E. Burmah, coll. Godwin-Austen ( NHMUK).

Description

SHELL. Sinistral, small, with very slightly elevated spire; whorls shouldered, which results in a nearly flat dorsal surface; fresh shells light brown; protoconch consists of 2.5 whorls, finely tuberculated; dorsal side and area inside umbilicus dominated by reticulated sculpture; periphery of body whorl dominated by radial lines; whorls 6–6.75 (n = 3), separated by moderately deep suture; peristome thickened and strongly reflected; parietal callus very strong, elevated, sharp, V-shaped, with the upper part of the V being shorter; apertural fold connected to parietal callus.

Two opened shells were examined. Parietal wall with a curved, long, posterior, and a shorter anterior lamella; main and intermediate plicae in contact with anterior lamella; main plica connected to apertural fold; intermediate plica about half as long as main plica; lower plica slightly extends beyond posterior lamella in posterior direction, and reaches peristome. Palatal plicae Plectopylis -like, with three additional horizontal plicae anterior to the vertical plate, which is formed by the accretion of the fourth and fifth plicae.

MEASUREMENTS (in mm). D = 8.8–9.9, H = 3.6–4.8 (syntypes, n = 2).

Differential diagnosis

The carinate shell and the horizontal palatal plicae anterior to the vertical plate make the identification of the species easy. A population of Chersaecia perrierae is similar in shape, but it has a single lamella. See also under that species.

Distribution

Chersaecia woodthorpei is known from the type locality only.