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

Figs 224 K, 240, 241

Gyliotrachela troglodytes van Benthem Jutting, 1950: 35–36, 47, fig. 21.

Gyliotrachela troglodytes — Maassen 2001: 77.

Type material examined.

Malaysia • 3 paratypes; from the type locality; Sept. 1941; Raffles Museum, Singapore ex. coll.; RMNH.Moll.137138 .

Type locality.

“ Gua Bama, Padang Tengku, Pahang ”, Malaysia.

Differential diagnosis.

This species can be separated from H. vicinum sp. nov. by the notably narrower umbilicus, weaker peripheral keel, and the absence of the basal and one interpalatal plica. Furthermore, the shell surface sculpture seems to be less rough than in H. vicinum sp. nov.

Distribution.

This species is known only from the type locality.

Remarks.

In the original description, an infraparietal lamella is mentioned. We observed it in paratypes but it should be noted that it is dot-like and very small.

4. Hypselostoma tubiferum group

Diagnosis. Hypselostoma tubiferum group is devoid of any peculiar shell surface sculpture. It is smooth or finely pitted with some radial growth lines.

Remarks. This group includes nine species. Their distribution spans from Guangxi, Guizhou, and Yunnan provinces in China southwards to Peninsular Malaysia. Westernmost localities are known from central Myanmar.