Bensonella tamphathai

Bensonella tamphathai (Panha & J. B. Burch, 2000) Paraboysidia tamphathai Panha & Burch, 2000: 107, fig. 2. Paraboysidia tamphathai — Panha and Burch 2008: 115, fig. 98. Bensonella tamphathai — Dumrongrojwattana and Wongkamhaeng 2024: 324. Material examined. Thailand • 4 shells; Lampang Province, limestone ridge, Ban Pang La; 18°35′7″N, 99°50′32″E; 400 m a. s. l.; 14. May 1988; F. G. Thompson leg.; locality code FGT-4438; UF 346895 • 11 shells; Lampang Province, limestone knoll 1 km NE of Ban Pang La; 18°33′15″N, 99°52′11″E; 400 m a. s. l.; 14. May 1988; F. G. Thompson leg.; locality code FGT-4436; UF 346878 • 14 shells; same data as previous; locality code FGT-4435; UF 380388 • 3 shells; Lampang Province, limestone mtn. 3 km SE of Ban Mae Moa ledge on NW slope of mtn., leaf litter; 18°14′3″N, 99°42′49″E; 500 m a. s. l.; 15. May 1988; F. G. Thompson leg.; locality code FGT-4443; UF 346921 • 2 shells; Lampang Province, 6 km SW Mae Pak, limestone hill, 17°57′53″N, 98°51′7″E (provided coordinates point in Lamphun province); 600 m a. s. l.; 13 June 1987; F. G. Thompson leg.; locality code FGT-4328; UF 346579. Type locality. “ Tam Pha Thai National Park, Lampang Province, 18°36'20"N, 99°53'49"E, 490 meters elevation ” (Thailand). Differential diagnosis. The most similar species is B. paviei which is however smaller and has less pronounced spiral sculpture. Apertural barriers are also more numerous than in B. paviei. Bensonella palatotridens is not spirally striated. Bensonella tamphathai has a blunter conical shell (i. e., more barrel-shaped), narrower umbilicus and fewer basal plicae than B. multidentata sp. nov. Bensonella multidentata sp. nov. is also much more densely spirally striated which makes it shell surface less shiny than in B. tamphathai. Bensonella nitens sp. nov. has a wider umbilicus, is more concave-conical and has a thin, sharp, and long projections of palatal plicae (proximally and distally). Also, the last whorl is B. nitens sp. nov. is much narrower than in B. tamphathai (i. e., it contributes less to the total shell height than in B. tamphathai). Bensonella sericata sp. nov. is much more densely spirally striated, lacks the basal plica and has weaker upper palatal plica. Bensonella microdentata sp. nov. has weaker apertural barriers which are roughly spiniferous. Distribution. This species is known from Lampang Province, Thailand.