Hypselostoma terae Tomlin 1939

Hypselostoma terae Tomlin, 1939 Figs 224 I, 235, 236, 237, 241 Hypselostoma terae Tomlin, 1939: 146, pl. 12, fig. 2. Hypselostoma terae — van Benthem Jutting 1949 b: 59; van Benthem Jutting 1950: 43; van Benthem Jutting 1950: 21–22, fig. 10; Berry 1963: pl. 5, fig. 42. Hypselostoma megaphonum van Benthem Jutting, 1950: 21–23, fig. 11. syn. nov. Hypselostoma megaphonum — van Benthem Jutting 1950: 42; Maassen 2001: 77. Hypselostoma perigyra van Benthem Jutting, 1950: 25–26, fig. 14. syn. nov. Hypselostoma perigyra — van Benthem Jutting 1950: 42; Maassen 2001: 77. Boysidia (Dasypupa) terae — Thompson and Dance 1983: 109. Boysidia (Dasypupa) megaphona — Thompson and Dance 1983: 109. Boysidia (Dasypupa) perigyra — Thompson and Dance 1983: 109. Type material examined. Malaysia • 53 paratypes of H. terae; from the type locality; RMNH Moll.137160 • 23 paratypes of H. perigyra; from the type locality; RMNH Moll.137163 • 23 paratypes of H. megaphonum; from the type locality; RMNH Moll.137161. Additional material examined. Malaysia • 2 shells; Pahang, Bukit Cinta Manis, SSE side, Lebuhraya Karak 800 m - Kampung Cinta Manis; 03°26.714'N, 102°00.814'E; 130 m a. s. l.; 22 Jan. 2013; A. Hunyadi leg.; coll. HA • 2 shells; Pahang, 25 km northwest from Kuantan, east from Kampung Panching, Gua Charas, rock temple; 03°54.692'N, 103°08.839'E; 140 m a. s. l.; 24 Jan. 2013; A. Hunyadi leg.; coll. HA • 1 shell; Selangor, Kual Lumpur E- Kanching, Templer Park, Perangsang Templer Golf Club, limestone rock; 03°17.878'N, 101°38.438'E; 100 m a. s. l.; 25 Jan. 2013; A. Hunyadi leg.; coll. HA • 25 shells; Pahang, 15 km west from Bandar Pusat Jengka, Hutan Lipur Gunung Senyum; 03°41.862'N, 102°25.980'E; 85 m a. s. l.; 23 Jan. 2023; A. Hunyadi leg.; coll. HA. Type localities. “ Bukit Chintamani, Pahang ” (Bukit Cinta Manis), Malaysia (H. terae); “ Bukit Charas, near Kuantan, Pahang ”, Malaysia (H. megaphonum); “ Bukit Takun, Kanching, Selangor ”, Malaysia (H. perigyra). Differential diagnosis. This species differs from H. elephas by its less detached and protruding last whorl as well as the much more conical shell. Distribution. This species is known from Pahang and Selangor provinces in Peninsular Malaysia. Remarks. Hypselostoma megaphonum and H. perigyra are synonymised with this species based on the following: i) all three species share the same arrangement and morphology of apertural barriers; ii) umbilici of all three species are equally narrow (with very slight variability which can be considered intraspecific); iii) all three species have the same narrow and sharp peripheral keel and iv) all three species are of similar size and distributed geographically close. All differences mentioned by van Benthem Jutting (1950) in the original description (last whorl inflation level, umbilicus width and apertural barrier strength) are recognised as intraspecific variability. Hypselostoma megaphonum can be interpreted as an intermediary form between H. terae and H. perigyra based on the following characters: i) last whorl more inflated than in H. terae but less than in H. perigyra; ii) apertural barriers stronger than in H. terae but weaker than in H. perigyra; iii) umbilicus wider than in H. terae but narrower than in H. perigyra.