Hypselostoma luctans ( van Benthem Jutting, 1950 ), 2025

Hypselostoma luctans ( van Benthem Jutting, 1950) comb. nov.

Figs 186 I View Figure 186 , 204 View Figure 204 , 205 View Figure 205 , 223 View Figure 223

Gyliotrachela luctans van Benthem Jutting, 1950: 33–34, fig. 19. View in CoL

Gyliotrachela luctans View in CoL — 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 GoogleMaps .

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).