Durgella concinna Blanford & Godwin-Austen,

Pholyotha, Arthit, Sutcharit, Chirasak, Lwin, Ngwe & Panha, Somsak, 2024, Positive association between PTN polymorphisms and schizophrenia in Northeast Chinese Han population., Zoological Studies 63 (14), pp. 141-149 : 13

Durgella concinna Blanford & Godwin-Austen,

1908 ( Figs. 1 , 7D )

Nanina levicula – Blanford 1865: 87. Nevill 1878: 26. (non Benson 1859).

Durgella concinna Blanford & Godwin-Austen, 1908: 215 . Type locality: Thayet Myo [Thayet District, Magway Region], Prome [Pyay District, Bago Region], and Akauktoung in Upper Pegu [Akauk Taung, Pyay District, Bago Region].

Material examined: Syntype NHMUK 1865.9.3.15 (1 shell; Fig. 7D ) from Akouktoung, Pegu [Akauk Taung, Pyay District, Bago Region, Myanmar].

Diagnosis: Shell depressedly globose, small, fairly solid, polished, very descending in front, with narrowly opened umbilicus.

Description: Shell ( Fig. 7D ). Shell depressedly globose, small (width up to 7 mm, height up to 4 mm), fairly solid, smooth, polished, translucent, pale, almost whitish-horny. Spire low, convex, apex obtuse; suture shallow. Whorls 3½, rapidly increasing, slightly convex above; last whorl descending near aperture, rounded, and rather tumid beneath. Aperture oblique, roundly lunate; peristome thin. Columellar margin curved, vertical above, and slightly reflected. Umbilicus narrow.

Distribution: Durgella concinna is known from several localities in Magway ( Fig. 1 ) and Bago regions in central Myanmar.

Remarks: Durgella concinna was nominated based on misidentified D. levicula specimens from central Myanmar ( Blanford and Godwin-Austen 1908). However, it differs from D. levicula in having the last whorl more descending near the aperture and a wider umbilicus. In contrast, D. levicula has a shell without a descending body whorl near the aperture and a tiny umbilicus.

The taxonomic status of D. concinna is still ambiguous because this species has a shell morphology that is very similar to D. erratica ; it differs from the latter species by having a slightly smaller shell. Unfortunately, no specimens of D. concinna were found in our surveys, and so we could not compare their reproductive morphologies. Additional information is necessary to determine whether the difference in shell size represents size variation or distinct species. In this study, we retain D. concinna as a valid species per Blanford and Godwin-Austen (1908).

Figures

Fig. 1. Map of Thailand and Myanmar showing the geographic distribution of eight species of Durgella based on the specimens examined herein. Only D. rhaphiellus is not shown on the map, as its type locality of “Siam” [Thailand] is too imprecise.

Fig. 7. Shells of Durgella species. A–C: D. erratica; A: syntypes NHMUK 1895.1.1.4–6; B, C: specimen CUMZ 14234. D: D. concinna syntype NHMUK 1865.9.3.15.