Bensonella paviei (Bavay & Dautzenberg, 1912)

Figs 39 W, 82, 83, 100

Boysidia paviei Bavay & Dautzenberg, 1912: 20, pl. 3, figs 4–6.

Boysidia (Paraboysidia) paviei — Pilsbry 1917: 203–204, pl. 35, figs 7–8; Schileyko 1998: 138, fig. 156; Chen et al. 1999: 1; Schileyko 2011: 2.

Paraboysidia paviei — van Benthem Jutting 1950: 39.

Paraboysidia nabhitabhatai Panha & Burch, 2002 c: 81–84, fig. 3. syn. nov.

Paraboysidia nabhitabhatai — Panha and Burch 2008: 113–114, fig. 96.

Paraboysidia anguloobtusus Inkhavilay & Panha in Inkhavilay et al. 2016: 215–217, figs 1, 2 D – F, 4 B. syn. nov.

Paraboysidia anguloobtusa — Inkhavilay et al. 2019: 61, fig. 26 F.

Bensonella paviei — Páll-Gergely and White 2023: 2015, fig. 3 f – k.

Bensonella anguloobtusa — Tongkerd et al. 2024: 171–174, figs 6 B, 7 A, 13 G.

Bensonella nabhitabhatai — Dumrongrojwattana and Wongkamhaeng 2024: 324.

Type material examined.

Vietnam • 1 syntype; Pac-Kha: Long-ping; C. Messager leg.; MNHN -IM-2000-35158 . Thailand • holotype of P. nabhitabhatai; 1998; S. Panha, P. Dumrongrojwattana, C. Sutcharit, S. Tumpeesuwan leg.; CUMZ ver. 064 .

Additional material examined.

Vietnam • 4 shells; Son La Province, 27 km east-southeast from centre of Phu Yen, Muong Do, Ban Han Mot, southern part of the village; 21°11.731'N, 104°47.129'E; 800 m a. s. l.; 06 Feb. 2020; A. Hunyadi, J. U. Otani & S. V. Pham leg.; coll. HA • 23 shells; Son La Province, Moc Chau district, Van Ho, northeastern edge of Pa Cop towards Bo Nhang; 20°46.001'N, 104°45.203'E; 980 m a. s. l.; 10 Feb. 2020; A. Hunyadi, H. V. Luong, J. U. Otani & S. V. Pham leg.; coll. HA • 31 shells; Son La Province, Yen Chau district, Xa Chieng On, Ban Tram Hoc, Hang Nha Nhung, vicinity of the cave; 20°59.483'N, 104°11.270'E; 970 m a. s. l.; 09 Feb. 2020; A. Hunyadi, H. V. Luong, J. U. Otani & S. V. Pham leg.; coll. HA • 110 shells; Son La Province, Quynh Nhai district, 20 km east from cross towards Thuan Chau, Chieng Khoang, cave above the village; 21°33.441'N, 103°40.909'E; 315 m a. s. l.; 07 Feb. 2020; A. Hunyadi, H. V. Luong, J. U. Otani & S. V. Pham leg.; coll. HA • 10 shells; Son La Province, Moc Chau district, Long Luong, Ban Tan Lap, northern edge of the village; 20°46.835'N, 104°50.752'E; 1165 m a. s. l.; 05 Feb. 2020; A. Hunyadi, H. V. Luong, J. U. Otani & S. V. Pham leg.; coll. HA • 4 shells; Sơn La Province, Thu ận Châu district, 900 m from centre of Co M ạ, rock wall above the road; 21°21.186'N, 103°31.676'E; 1300 m a. s. l.; 08 Feb. 2020; A. Hunyadi leg. ; Laos • 37 shells; Udomxai Province, 6.5 km southeast from centre of Na Mor towards Udomxai, Ban Nathong, Tham Nathong, above cave spring; 20°52.369'N, 101°46.981'E; 635 m a. s. l.; 07 Oct. 2019; A. Hunyadi leg.; coll. HA • 1 shell; Luang Prabang Province, 28.5 km south from Pak Mong towards Luang Prabang, northern bank of Nam Nga, Tham Nam Nga; 20°22.220'N, 102°20.078'E; 350 m a. s. l.; 09 Oct. 2019; A. Hunyadi leg.; coll. HA • 45 shells; Luang Prabang Province, 10.3 km from centre of Luang Prabang towards Xiang Ngeum, east, 1800 m on a path, Phou Xuang, eastern mountain slope; 19°51.526'N, 102°11.100'E; 730 m a. s. l.; 10 Oct. 2019; A. Hunyadi leg.; coll. HA • 26 shells; Luang Prabang Province, 12 km from centre of Nong Khiaw towards Pak Xeng, northeast from Ban Huai Lek, left side of the road; 20°32.585'N, 102°41.161'E; 350 m a. s. l.; 05 Oct. 2019; A. Hunyadi leg.; coll. HA • 103 shells; Luang Prabang Province, 2.8 km northeast from Phou Khoun, rock wall above the cave; 19°26.787'N, 102°26.338'E; 1200 m a. s. l.; 11 Oct. 2019; A. Hunyadi leg.; coll. HA • 113 shells; Udomxai Province, 10 km southeast from centre of Na Mor, 3.8 km east-northeast from Na Xay, northern rock wall; 20°53.371'N, 101°48.963'E; 660 m a. s. l.; 07 Oct. 2019; A. Hunyadi leg.; coll. HA • 5 shells; Xieng Khouang Province, ca 15 km SW of Ban Ko Kieng, ca 19 km SW of Vieng Thong, on the left side of Nam Khan, under rocks and logs in old forest; 19°56.264'N, 103°15.763'E; 570 m a. s. l.; 27 Oct. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27287 • 3 shells; Luang Prabang Province, ca 6 km E of Muang Xiang Ngeun, under rocks in old secondary forest under cliff; 19°44.690'N, 102°15.193'E; 390 m a. s. l.; 21 Nov. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27288 • 2 shells; Luang Prabang Province, Phou Xuang mountain, ca 1.5 km NE of Ban Lak Sip, ca 5 km SE of Luang Prabang, under rocks and logs in old secondary forest under cliff; 19°51.605'N, 102°11.081'E; 640 m a. s. l.; 24 Nov. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27270 • 1 shell; Luang Prabang Province, ca 18 km SE of Muang Xiang Ngeun, on the left side of Nam Khan, under rocks and logs in old forest; 19°40.931'N, 102°19.743'E; 455 m a. s. l.; 30 Oct. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27285 • 9 shells; Xieng Khouang Province, ca 30 km WNW of Phonsavan, ca 47 km ENE of Phou Khoun, limestone, black soil in limestone pockets, clay, under rocks in old secondary forest at base of cliff near cave; 19°32.019'N, 102°51.901'E; 1131 m a. s. l.; 15 Nov. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27272 • 6 shells; Luang Prabang Province, just NE of Phou Khoun, under rocks in old secondary forest above large cave; 19°26.784'N, 102°26.290'E; 1177 m a. s. l.; 15 Nov. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27289 • 12 shells; Xieng Khouang Province, Plane of Jars, Site 1, ca 6 km S of Phonsavan, limestone, clay, under rocks near small trees under cliff surrounded by grassland; 19°25.819'N, 103°09.216'E; 1097 m a. s. l.; 14 Nov. 2006; I. V. Muratov leg.; MNHN -IM-2012-27286 • 12 shells; Luang Prabang Province, ca 17 km SE of Muang Xiang Ngeun, along small stream on the left side (ca 2 km S) of Nam Khan, on and under rocks and logs in old forest with banana; 19°40.188'N, 102°18.538'E; 525 m a. s. l.; 31 Oct. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27273 • 22 shells; Luang Prabang Province, ca 6 km N of Phou Khoun, under rocks in dry secondary forest under and above cliff; 19°29.653'N, 102°24.470'E; 1244 m a. s. l.; 16 Nov. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27271 • 28 shells; Xieng Khouang Province, ca 18 km SW of Ban Ko Kieng, ca 22 km SW of Vieng Thong, on the right side of Nam Khan, under rocks and logs at base of cliff in secondary forest; 19°54.842'N, 103°14.392'E; 560 m a. s. l.; 28 Oct. 2006; A. Abdou, I. V. Muratov leg.; MNHN -IM-2012-27284 . Myanmar • 1 shell; Mandalay, Anesakhan, Dat Taw Gyaint Waterfall; 21°58.760'N, 96°23.116'E; 610 m a. s. l.; 18 Oct. 2018; Hunyadi leg; coll. HA . Thailand • 51 shells; Chiang Mai Province, northeastern side of Doi Chiang Dao, 2 km northwest from Wat Tham Chiang Dao; 19°24.016'N, 98°54.680'E; 835 m a. s. l.; 07 Feb. 2015, A. Hunyadi leg.; coll. HA • 3 shells; Mae Hong Song Province, 10.2 km WNW of Soppong, road 1095; 19°33'N, 98°3'E; 820 m a. s. l.; 23 Mar. 1998; K. Auffenberg leg.; locality code KA-0586; UF 345620 .

Type localities.

“ Pac-Kha ”, Vietnam ( B. paviei); “ Limestone wall outside of Kao Rao. Cave, Vieng Phouka District, Luang Namtha Province, Laos (20°43'30.1"N, 101°9'4.3"E), 732 m amsl ” ( Paraboysidia anguloobtusus); “ Phadevada, Phukhieo Wildlife Sanctuary, Chaiyapumi Province, 16°3'20"N, 101°34'14"E, 110 meters elevation … ” ( P. nabhitabhatai).

Differential diagnosis.

This species is smaller, with less numerous apertural barriers and a narrower umbilicus than Bensonella multidentata sp. nov. B. palatotridens is not spirally striated. This species differs from B. microdentata sp. nov. in the less glossy shell surface, stronger apertural barriers and non-spiniferous aperture surface (including the barriers). See also under B. tamphathai . This species is also similar to B. nitens but can be separated by the much less glossy shell surface and stronger and fewer apertural barriers.

Distribution.

This species is known from several localities in Laos (Xieng Khouang, Udomxai and Luang Prabang provinces), Vietnam (Son La province), Myanmar (Shan State, see Tongkerd et al. 2024, Mandalay) as well as Thailand (Chiang Mai, Mae Hong Son and Chaiyapumi provinces).

Remarks.

Paraboysidia anguloobtusa described from a Kao Rao Cave, Vieng Phouka District, Luang Namtha Province, Laos (20°43'30.1"N, 101°9'4.3"E) and Paraboysidia nabhitabhatai described from Phadevada, Phukhieo Wildlife Sanctuary, Chaiyapumi Province, Thailand (16°3'20"N, 101°34'14"E) are both herein considered junior synonyms of B. paviei since no morphological differences were observed. Inkhavilay et al. (2016) stated that P. anguloobtusa has a different shell shape than B. paviei and that it has a blunt angular lamella. However, the shell shape of both species is the same (conical to slightly concave-conical) and both species have a blunt angular lamella. Other differences mentioned for apertural barriers (infraparietal situated closer to the parietal and angular lamellae, suprapalatal absent, lamellae more twisted) are considered minor intraspecific variation. The umbilicus in B. paviei is not widely opened as stated by Inkhavilay et al. (2016) but rather narrow and of the same appearance as that in Paraboysidia anguloobtusa . Sometimes, the last whorl of B. paviei is more or less enlarged, but the apertural barrier arrangement is largely consistent. Spiral striation can vary in strength but is always present.