Burmochlamys perpaula (Benson, 1859) Pholyotha & Sutcharit & Lin & Panha, 2022

Pholyotha, Arthit, Sutcharit, Chirasak, Lin, Aung & Panha, Somsak, 2022, Uncovering local endemism from southeastern Myanmar: description of the new karst-associated terrestrial snail genus Burmochlamys (Eupulmonata, Helicarionidae), ZooKeys 1110, pp. 1-37 : 1

Burmochlamys perpaula (Benson, 1859) comb. nov.

Fig. 6D

Helix perpaula Benson, 1859: 390. Type locality: Phie Thán, raro [Phie Than, Tenasserim Valley].

Helix perpaula - Pfeiffer, 1868: 69.

Nanina (Macrochlamys) perpaula - Tryon, 1886: 89, pl. 29, fig. 37.

Macrochlamys perpaula - Godwin-Austen, 1883: 89, pl. 14, fig. 5; Blanford and Godwin-Austen 1908: 123; Pholyotha et al. 2020b: 187, 188, fig. 3b.

Material examined.

Type material. The type series could not be located.

Other material.

Moulmein: NHMUK 1903.7.1.533 ex. Godwin-Austen Coll. (one shell; Fig. 6D ; specimen figured in Godwin-Austen 1883: pl. 14, fig. 5 and Pholyotha et al. 2020b: fig. 3b), NHMUK ex. MacAndrew Coll. Acc. No. 1563 (six shells), NHMUK 1912.4.16.400 (three shells).

Remarks.

Burmochlamys perpaula is currently known only from the type locality in Tenasserim Valley ( Benson 1859; Blanford and Godwin-Austen 1908). The original type series could not be located, and no specimens were found in this study. Therefore, the generic placement is still provisional and awaiting for further anatomical information. However, Helix perpaula is transferred to this new genus, which it distinct from the Macrochlamys by a numbers of shell morphology (see Pholyotha et al. 2020b).

Burmochlamys perpaula is characterised by subglobose, small size (width of ~ 2.0 mm, height of ~ 1.3 mm), obliquely striated and very minutely spirally ribbed throughout, moderately elevated spire, rather more convex body whorl, and narrowly crescent-shaped aperture, simple peristome, simple columellar margin with slightly reflected near umbilicus, and narrowly open umbilicus (Fig. 6D ; Benson 1859; Blanford and Godwin-Austen 1908). In addition, this species can be distinguished from all other congeners by its moderately elevated spire, rather more convex body whorl, and narrower umbilicus. In comparison, most species of Burmochlamys gen. nov. have a higher shell spire, rather broad and well-rounded last whorl, and relatively wider umbilicus.

Figures

Figure 6. Shells of Burmochlamys species A, B B. cassidula specimen CUMZ 14209 C B. cauisa specimen NHMUK 1888.12.4.465 - 466 D B. perpaula specimen NHMUK 1903.7.1.533 E, F B. poongee E specimen NHMUK 1888.12.4.23 - 6 F specimen CUMZ 14210.