Hypselostoma luctans (van Benthem Jutting, 1950) comb. nov. Figs 186 I, 204, 205, 223 Gyliotrachela luctans van Benthem Jutting, 1950: 33–34, fig. 19. Gyliotrachela luctans — van Benthem Jutting 1950: 46; Zilch 1984: 166; Maassen 2001: 76; Foon et al. 2017: 79, fig. 30 C. Type material examined. Malaysia • 23 paratypes; from the type locality; 1938; Raffles Museum Singapore ex. coll.; RMNH.Moll.137158. Additional material examined. Thailand • 7 shells; Yala Province, 9.5 km from the junction to Bannang Sata, 1700 m north from the road no 4077, left side of the side road; 6°19.803'N, 101°13.135'E; 120 m a. s. l.; 22 Feb. 2023; A. Hunyadi leg.; coll. HA. Type locality. “ Gunong Pondok, Padang Rengas, Perak ”, Malaysia. Differential diagnosis. This species is similar to H. bubalus sp. nov. with which it is also geographically approximate. It differs from it by a clearly narrower umbilicus. Hypselostoma bubalus sp. nov. is also spirally striated on some isolated parts of the shell (above or below the keel), but H. luctans is not. See also under H. piconis. Distribution. This species is known from Peninsular Malaysia and Yala Province in Thailand. Remarks. There can be two interpalatal plicae, and in some cases, none are visible. Umbilicus can sometimes be slightly wider, with a stronger groove inside (than the figured specimen).

Published as part of Gojšina, Vukašin, Hunyadi, András, Sutcharit, Chirasak, Tongkerd, Piyoros, Auffenberg, Kurt, Grego, Jozef, Vermeulen, Jaap J., Reischütz, Alexander & Páll-Gergely, Barna, 2025, A new start? Revision of the genera Anauchen, Bensonella, Gyliotrachela and Hypselostoma (Gastropoda, Eupulmonata, Hypselostomatidae) of Southeast Asia with description of 46 new species, pp. 1-338 in ZooKeys 1235 on pages 1-338, DOI: 10.3897/zookeys.1235.145281