Hypselostoma bubalus Gojšina, Hunyadi & Páll-Gergely, 2025

Hypselostoma bubalus Gojšina, Hunyadi & Páll-Gergely sp. nov.

Figs 186 B View Figure 186 , 188 View Figure 188 , 189 View Figure 189 , 223 View Figure 223

Type material.

Holotype. Malaysia • 1 shell (SH: 2 mm; SW: 3.7 mm); Kedah, 1.5 km east from Kodiang, Gua Kerbau ; 06°23.431'N, 100°18.904'E, 14 Jan. 2013; A. Hunyadi leg.; CUMZ 14466 View Materials . GoogleMaps

Paratypes. Malaysia • 216 shells; same data as for holotype; coll. HA GoogleMaps • 1 shell; same data as for holotype; coll. VG GoogleMaps .

Additional material examined.

Malaysia • 25 shells (damaged, not paratypes); same data as for holotype; coll. HA GoogleMaps .

Type locality.

Malaysia, Kedah, 1.5 km east from Kodiang, Gua Kerbau; 06°23.431'N, 100°18.904'E.

Diagnosis.

Shell depressed, concave-conical. Teleoconch finely radially and spirally striated (localised, just below and above the keel on the last whorl). Last whorl detached from the penultimate and strongly ascending. Aperture wide, equipped with five main barriers (angular, parietal, upper palatal, lower palatal and columellar) and two smaller barriers (basal and infraparietal). Umbilicus wide, measuring 50 % of the shell width.

Description.

Shell depressed, concave-conical, chestnut brown, very weakly glossy and not translucent. Whorls 3.5–4, initially weakly convex, separated by a deep suture, regularly increasing until the last whorl which is strongly enlarged and flat. Protoconch lighter than the rest of the shell, finely pitted without spiralling pattern, consisting of ~ 1.25 whorls. Teleoconch very finely granulated (sandpaper-like surface) and radially striated with additional whitish radial streaks which are weak, widely, and irregularly spaced. Spiral striae present but localised, clearly visible only on the last whorl above and below the keel, elsewhere absent. Sometimes, spiral striae are very difficult to observe on the whole shell. Last whorl strongly enlarged in comparison to previous ones, bluntly keeled very slightly above the centre of the periphery (or sometimes at the centre of the periphery) and almost flat above and weakly convex below the keel. Keel is strongest near the aperture. Last whorl moderately to strongly ascending near the aperture (~ 50–65 ° compared to the shell axis) and moderately detached from the penultimate whorl. Peristome very pale brownish, strongly expanded but not reflected. Aperture equipped with five main barriers (angular, parietal, upper palatal, lower palatal, and columellar). Angular lamella short and small, directed towards the upper palatal plica. Parietal lamella strong and high, not much longer than the angular and only reaching its profile. Upper palatal plica slightly weaker than the parietal lamella and bent towards the lower palatal plica. Lower palatal plica straight, equally strong as the upper palatal but not bent. Columellar lamella is the broadest in the aperture but relatively short. Between these main barriers, additional small basal and infraparietal plicae visible. Surface of all apertural barriers is very finely spiniferous medially and very finely granulated laterally. Sinulus small and distinctly separated from the rest of the aperture. Umbilicus very wide, measuring half of the shell width and showing all previous whorls. A deep and wide groove is running from the columellar side of the peristome alongside the umbilicus.

Differential diagnosis.

See under H. luctans .

Measurements

(in mm, n = 5). SH = 2–2.23; SW 1 = 3.40–4.13; SW 2 = 1.95–2.41; AH = 1.44–1.78; AW = 1.33–1.61.

Etymology.

The type locality of this species, Gua Kerbau, means “ Buffalo cave ” in Malay. The specific epithet bubalus is also a scientific name for a buffalo, which is to be used as a noun in apposition.

Distribution.

This species is known only from the type locality.

Remarks.

Although this species shows some spiral striation, it is placed into H. hungerfordianum group because of the predominant sandpaper-like surface on the teleoconch.