23 Paropeas swettenhami (de Morgan, 1885)

Fig. 12 D

Stenogyra swettenhami de Morgan, 1885: 389, pl. 6, fig. 6. Type locality: G. Tchöra, près ďIpoh (Kinta) [Gunung Cheroh, Ipoh, Perak State, Malaysia].

Prosopeas swettenhami — Pilsbry 1906: 32, pl. 4, figs 11, 12. Laidlaw 1933: 216.

Paropeas swettenhami — Naggs 1994: 188.

Type specimen.

Syntype MNHN - IM- 2000-38930 (1 shell; Fig. 12 D) from Malacca, G. Tchéhèl.

Diagnosis.

Shell slender, elongate turreted and rapidly attenuated; apex pointed; subsequent whorls coarse with dense and fine radial striae. Suture wide and shallow, and whorls flattened. Aperture elongate ovate; columella concave.

Distribution.

This species has been reported from Malaysia and Shan State, Myanmar (Naggs 1994).

Remarks.

de Morgan (1885) describes P. swettenhami and P. tchehelense consecutively in the same publication and from a very close geographical area within Perak State, Peninsular Malaysia. Then von Möllendorff (1891: 337) suggests ‘ Stenogyra swettenhami de Morgan, 1885 ’ as a slight variation of P. tchehelense; therefore, some subsequent authors recognise the former as a synonym of the latter (i. e., Maassen 2001; MolluscaBase 2023). In contrast, Pilsbry (1906: 32) argues that they differ in shell shape and structure. We have examined the syntypes of both species and agree with Pilsbry (1906) that P. swettenhami (Fig. 12 D) differs from P. tchehelense by having a slimmer shell, narrower aperture, cylindrical and rounded embryonic whorls. Prosopeas tchehelense (Fig. 12 E) possesses a large, broad shell, wide aperture, convex, and rounded embryonic whorls.

No new materials of this species were found in this survey, and the type specimen is illustrated herein. Naggs (1994) provisionally reported the occurrence of P. swettenhami from Shan State, Myanmar. Considering the vast geographical distance between Perak and Shan State, it may be that the specimens Naggs (1994) regarded as P. swettenhami are, in fact, P. terebralis or another species. However, collecting topotypical material from Shan State, Myanmar, is necessary to confirm the existence of this species in Myanmar and the systematic relationship with P. tchehelense .