Boysidia Ancey, 1881

Inkhavilay, Khamla, Sutcharit, & Chirasak, 2024, A new pulmonate microsnail species in the genus Boysidia, with remarks on Bensonella and Krobylos species (Pupilloidea: Hypselostomatidae) from northern Laos, Raffles Bulletin of Zoology 72, pp. 438-449 : 440

Genus Boysidia Ancey, 1881

Pupa ( Boysidia ) Ancey, 1881: 373.

Pupa ( Gredleriella ) von Möllendorff, 1884: 179, 180. Type species: Pupa hunana Gredler, 1881 , by original designation [‘ hunanensis ’ is an incorrect subsequent spelling by von Möllendorff (1884)].

Hypselostoma (Boysidia) — Pilsbry & Vanatta, 1900: 592. Pilsbry & Hirase, 1908: 42.

Boysidia — Gude, 1914: 293, 294. Pilsbry, 1917: 192. Thiele, 1931: 514. Zilch, 1959: 163. Schileyko, 1998: 137. Panha & Burch, 2005: 61.

Boysidia (Dasypupa) Thompson & Dance, 1983: 105 , 106. Schileyko, 1998: 138. Type species: Boysidia salpinx Thompson & Dance, 1983 , by original designation.

Type species. Pupa dorsata Ancey, 1881 , by subsequent designation in Gude, 1914: 239.

Diagnosis. Shell conic to elongate conic, brownish to chestnut-brown, 5 to 7 convex whorls. Shell surface with dense and irregular growth lines. Aperture vertical to subvertical; peristome broadly expanded; lip adnate to preceding whorl or little elevated with very short tuba. Apertural dentitions generally four or five (type species; Fig. 1A, B ) or more: one on parietal wall (in the case of angular concrescent with parietal lamella), upper and lower palatal plicae, columellar lamella, and additional dentitions (basal, palatal tubercle or infraparietal) may be present. Umbilicus narrow or perforate.

Remarks. Originally, Boysidia was described as a subgenus of Pupa Röding, 1798. Subsequently, Pilsbry and Vanetta (1900: 592) transferred Boysidia to a subgenus of Hypselostoma Benson, 1856 . Not long after, Gude (1914) raised Boysidia to a full genus that comprised hypselostomatid species without tuba, without spiral striation, and with a large independent or concrescent parietal lamella. This definition has been widely used and followed since then. Currently, Boysidia contains some 35 nominal species that are broadly distributed ( Páll-Gergely & White, 2022; MolluscaBase, 2024). There are 19 species from China, six from Indochina, and eight from Malaysia, including Borneo ( Zhang et al., 2014; MolluscaBase, 2024). In addition, there are two species with disjunct distributions: one from Timor and another from Pakistan ( Rensch, 1935; Pokryszko et al., 2009). Among these, only two species, Boysidia pahpetensis Saurin, 1953 and Boysidia houaphanica , new species, are now known from Laos.

When examining the specimens from China, von Möllendorff (1884) described Pupa ( Gredleriella ) with Pupa hunana Gredler, 1881 as the type species. Later, in a taxonomic revision of Boysidia, Pilsbry (1917: 194) recognised three subgenera: the nominotypical subgenus Boysidia , Bensonella Pilsbry & Vanatta, 1900 and Paraboysidia Pilsbry, 1917. However, the type species of Gredleriella (Pupa hunana Gredler, 1881 ; Fig. 1C ) is very similar to the type of Boysidia sensu stricto (Pupa dorsata Ancey, 1881 ; Fig. 1A, B ) in general shell form and the apertural dentitions. Therefore Pilsbry (1917: 194) synonymised subgenus Gredleriella with the nominotypical subgenus. This subgeneric classification was widely used (e.g., Schileyko, 1998) until Páll-Gergely and White (2022) formally synonymised Paraboysidia with Bensonella and recognised Bensonella as a distinct genus based on apertural dentition. The results of this generic revision by Páll-Gergely and White (2022) are followed by Tongkerd et al. (2024) and Jirapatrasilp et al. (2024).

Dasypupa was nominated as a subgenus of Boysidia with the distinguishing characters of a depressed-conical shell without spiral ridges, a concresent lamella with a small and bilobed blade, and having a small columellar lamella that is situated deep inside the aperture ( Thompson & Dance, 1983). Based only on similarity in shell morphology and apertural dentition, Pokryszko et al. (2009) applied this subgeneric name to a new Boysidia species from Pakistan. Nevertheless, the published re-description of the type species of Dasypupa , Boysidia salpinx Thompson & Dance, 1983 ( Fig. 1D ), in the handbook of land snails and slugs of Sabah and Labuan ( Vermeulen & Liew, 2022: 338, 339) does not recognise this subgenus, and rejects applying this subgenus without apparent reason. The current status of the subgenus Dasypupa is uncertain and its position and relationship with Boysidia need further study.

Figures

Fig. 1. A, B, Boysidia dorsata (Ancey, 1881), syntypes NMW 1955.158.24119 from Poyang Hu, Jiangxi, China. C, Boysidia hunana (Gredler, 1881), lectotype SMF 4192 from Hunan [Yün-Tscheu-fu], China. D, Boysidia salpinx Thompson & Dance, 1983, holotype UF 35944 from Gunong Subis, Miri Division, Sarawak, Malaysia. Abbreviations: b: basal plica, c: columellar lamella, lpl: lower palatal plica, p: parietal lamella, pl: palatal plica, upl: upper palatal plica. Photos: B. Páll-Gergely (A–C) and V. Gojšina (D).