Bensonella multidentata Gojsina, A. Reischutz & Pall-Gergely 2025, sp. nov.

Bensonella multidentata Gojšina, A. Reischütz & Páll-Gergely sp. nov. Figs 39 O, 69, 70, 71, 72, 100 Type material. Holotype. Thailand • 1 shell (SH: 2.40 mm, SW: 1.95 mm); Chiang Rai Province, Wat Phra That Tham Doi Khong Khao Meditation Centre, cave clay at the entrance of the cave, ca 6 km W of Chiang Rai; 19°54.771'N, 99°46.607'E; ca 420 m a. s. l.; Sept. 2017; A. Reischütz leg.; NHMW - MO-113729. Paratypes. Thailand • 1 shell; same data as for holotype; CUMZ 14439 • 29 shells; same data as for holotype; coll. REI • 1 shell; same data as for holotype; coll. VG • 41 shells; Chiang Rai Province, 5 km west from centre of Chiang Rai, vicinity of Wat Phra That Tham Doi Kong Khao; 19°54.820'N, 99°46.642'E; 420 m a. s. l.; 11 Feb. 2015; A. Hunyadi leg.; coll. HA. Additional material examined. Thailand • 3 shells (damaged / juveniles, not paratypes); same data as for holotype; coll. REI • 2 shells; Chiang Rai Province, south-southwest from Mae Sai, vicinity of Wat Tham Pla; 20°19.723'N, 99°51.817'E; 400 m a. s. l.; 12 Feb. 2015; A. Hunyadi leg.; coll. HA • 22 shells; Chiang Rai Province, limestone Mtn. 6 km by road W of Ban Mae Suai; 19°38′55″N, 99°26′41″E; 650 m a. s. l.; 07. May 1988; F. G. Thompson leg.; locality code FGT-4415; UF 347105. Type locality. Thailand, Chiang Rai Province, Wat Phra That Tham Doi Khong Khao Meditation Centre, cave clay at the entrance of the cave, ca 6 km NW of Chiang Rai, 19°54.771'N, 99°46.607'E, ca 420 m a. s. l. Diagnosis. A Bensonella species with high triangular, concave-conical, densely spirally striated shell. Last whorl wide, rounded. Multiple (at least 10) well-developed apertural barriers. Description. Shell light brown, triangular, concave-conical, whorls 5–5.25, convex, rounded, rather regularly increasing. Protoconch consisting of ~ 1.25 whorls, its sculpture consists of ~ 10 equidistant spiral striae. Teleoconch finely, very densely spirally striated, and ornamented with a few, inconspicuous radial growth lines. Last whorl adnate to the penultimate and slightly to moderately descending near the aperture (~ range: 15–32 ° compared to the shell axis) making the aperture profile prosocline to the shell axis. Aperture subcircular, parietal part strongly extended towards penultimate whorl. Peristome strongly expanded, not reflected. Aperture with numerous and strong barriers. A blunt, knob-like palatal tubercle sits anterior to the upper palatal plica on the peristome edge. Sometimes, this tubercle is very weak or completely absent. All other barriers sit deeper, not reaching the peristome edge. Parietal lamella is the highest among all apertural barriers, long, almost straight, only slightly curved downwards. Angular lamella much lower and more slender than the parietal one. Upper palatal plica short and located slightly above the palatal tubercle. First interpalatal and lower palatal plicae equally strong. There is a smaller and shorter second interpalatal plica between them. Basal part of peristome with two or three low plicae (rarely one), they are situated next to each other, the one situated closer to the columellar lamella may be homologous with the subcolumellar lamella, and the other may be basal plicae. Columellar lamella is weaker than parietal and stronger than the palatal plicae, straight, pointing obliquely upwards. Supracolumellar and infraparietal denticles small, knob-like. Surface of all apertural barriers is finely granulated. Sinulus parabolic, wide, and not strongly separated from the rest of the aperture. Umbilicus wide, covers 1 / 3–1 / 4 of shell width. Differential diagnosis. See under B. nitens sp. nov., B. paviei, B. sericata sp. nov. and B. tamphathai. Measurements (in mm, n = 5). SH = 2.40–2.51; SW = 1.81–1.97; AH = 0.82–0.94; AW = 0.85–0.95. Etymology. Named for the numerous barriers in the aperture. Distribution. This species is known from four localities in Chiang Rai province, Thailand. Remarks. The population found near Ban Mae Suai is characterised by shells that lack the palatal tubercle (or have a very slight swelling indicating its presence) and smaller number of apertural barriers (only one basal and one interpalatal). However, we do not intend to regard this population as distinct due to the lack of extensive material and the fact that main shell characters are shared with B. multidentata sp. nov. (shell shape, surface sculpture, umbilicus width and appearance of other barriers).