Bensonella dha Gojšina, Hunyadi & Páll-Gergely, 2025

Bensonella dha Gojšina, Hunyadi & Páll-Gergely sp. nov.

Figs 39 D View Figure 39 , 46 View Figure 46 , 47 View Figure 47 , 97 View Figure 97

Type material.

Holotype. Myanmar • 1 shell (SH: 1.9 mm, SW: 1.3 mm); Shan State, 5.8 km from centre of Hopong towards Namsang, left side of road # 4, Hopong Spring Cave ; 20°49.028'N, 97°13.469'E; 1110 m a. s. l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; CUMZ 14435 View Materials . GoogleMaps

Paratypes. Myanmar • 34 shells; same data as for holotype; coll. HA GoogleMaps • 1 shell; same data as for holotype; coll. VG GoogleMaps .

Type locality.

Myanmar, Shan State, 5.8 km from centre of Hopong towards Namsang, left side of road # 4, Hopong Spring Cave; 20°49.028'N, 97°13.469'E; 1110 m a. s. l.

Additional material examined.

Myanmar • 2 shells (juveniles, not paratypes); same data as for holotype; coll. HA GoogleMaps • 4 shells; Shan State, 22 km from centre of Hopong towards Namsang, Htem Sann Cave ; 20°49.0836'N, 97°20.1192'E; 1240 m a. s. l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA GoogleMaps • 2 shells; Shan State, 13.5 km east-southeast from centre Kalaw, Myinmati Taung ; 20°35.426'N, 96°36.794'E; 1350 m a. s. l.; 03 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA GoogleMaps • 11 shells; Shan State, 7.4 km from centre of Hopong towards Namsang, 5 km north on road # 4, Parpant cave ; 20°50.963'N, 97°14.267'E; 1170 m a. s. l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA GoogleMaps • 4 shells; Shan State, Kalaw, Shwe Oo Min Paya ; 20°37.2616'N, 96°33.4735'E; 1340 m a. s. l.; 02 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA GoogleMaps .

Diagnosis.

Bensonella species with conical shell which is not spirally striated. Apertural barriers numerous (angular, parietal, five palatals, one basal, one subcolumellar, one columellar, and one infraparietal) and with additional, strong palatal tubercle. Aperture well rounded.

Description.

Shell conical to conical-ovoid, light brownish and weakly glossy, consisting of 4.25–5.5 convex rounded whorls separated by a deep suture. Protoconch roughly pitted, sometimes with a spiralling pattern and consisting of ~ 1.5–1.75 whorls. Teleoconch with fine pasty structure, not spirally striated but with very fine radial growth lines. Last whorl adnate to the penultimate, aperture profile only slightly prosocline to the shell axis due to the slightly descending last whorl (~ 15 ° compared to the shell axis). Peristome slightly lighter than the rest of the shell, expanded but not reflected. It is particularly expanded on the parietal side where it forms a weak callus which is leaned on the penultimate whorl. Aperture equipped with moderately strong, numerous barriers. Parietal lamella moderately strong and high. Angular lamella longer but overall weaker than the parietal. It is higher in its inner part and regularly tapering towards the peristome, which is not reached. There are two or three very weak barriers inside the sinulus. Palatal wall equipped with five long barriers (suprapalatal, upper palatal, interpalatal, lower palatal, and infrapalatal) and a single strong palatal tubercle sitting on the edge of the palatal lip. Suprapalatal plica weak, not much stronger than the sinulus plicae. Upper palatal plica only slightly stronger than the suprapalatal. Interpalatal moderate. Lower palatal is the strongest among all the palatal plicae. Infrapalatal weak and shorter than others. Basal plica developed to the same extent as the infrapalatal. Subcolumellar lamella weak and short (nearly the same as the basal and infrapalatal). Columellar lamella strong as the lower palatal, almost horizontal. Infraparietal lamella moderate, ~ ½ as strong as the columellar. Surface of all apertural barriers is finely granulated. Sinulus small and not very distinctly separated from the rest of the aperture. Umbilicus very narrow, dot-like.

Differential diagnosis.

This species differs from B. cristatissima sp. nov. by the thinner peristome, less elongated apertural barriers and by the absence of a strong and sharp cervical crest.

Measurements

(in mm, n = 13). SH = 1.56–2.02; SW = 1.14–1.53; AH = 0.64–0.78; AW = 0.64–0.73.

Etymology.

Named after the Burmese word for sword / knife (dha) referring to the blade-like anterior part of the palatal plicae. To be used as a noun in apposition.

Distribution.

This species is known from five localities in Shan State, Myanmar.

Remarks.

We have observed some intraspecific variability between the populations. The population from Shwe Oo Min Paya is the smallest and with the most ovoid shell. While the populations from Myinmati Taung and Parpant cave were the most triangular with slightly shallower sutures.