Tonkinospira chytrophora (Mabille, 1887) Páll-Gergely & Grego & Vermeulen & Reischütz & Hunyadi & Jochum, 2019

Páll-Gergely, Barna, Grego, Jozef, Vermeulen, Jaap J., Reischütz, Alexander, Hunyadi, András & Jochum, Adrienne, 2019, New Tonkinospira Jochum, Slapnik & Páll-Gergely, 2014 species from Laos and Vietnam (Gastropoda: Pulmonata: Hypselostomatidae), Raffles Bulletin of Zoology 67, pp. 517-535 : 518-520

Tonkinospira chytrophora (Mabille, 1887) , new combination

( Fig. 3 )

Helix chytrophora J. Mabille, 1887a: 4 . (type locality: Tonkin [= northern Vietnam])

Helix chytrophora — J. Mabille, 1887b: 91–92.

Types examined. Lectotype, designated herein (H: 1.16 mm, D: 1.28 mm, Fig. 3 ) (MNHN-IM-2000-32862), Tonkin, coll. Balansa, 1887; 4 paralectotypes (MNHN-IM-2014-6407), same data as preceding. An additional label states “Anauchen, det. Schileyko ”.

Diagnosis. A small Tonkinospira species with a depressedglobular shell, dense spiral striation, and a nearly adnate peristome.

Description. Shell small for the genus; depressed-globular with rounded body whorl; translucent when fresh; 4.5 whorls, regularly increasing; shell slightly wider than tall; protoconch consists of 1.25 whorls, rather roughly pitted, without spiral lines; teleoconch with irregular radial growth lines, and dense, regular spiral striation, ca. 30 in number in the middle shell line from apertural view; aperture strongly oblique to shell axis from lateral view; aperture subcircular; peristome expanded but not reflected; nearly adnate to penultimate whorl, although callus discernible; umbilicus Diagnosis. A medium sized Tonkinospira species with a convexly conic shell, nearly absent spiral striation and strong, widely-spaced ribs, and an adnate peristome.

Description. Shell medium sized for the genus; convexly conic with rounded (slightly shouldered) body whorl; shell white, probably transparent when fresh; 4.5 whorls, regularly increasing; suture deep; protoconch finely rugose consisting of 1.25 whorls and spiral striation; teleoconch with rather regular, widely spaced ribs with fine wrinkles between ribs; aperture oblique to shell axis from lateral view; aperture subcircular with straight columellar and parietal part; slight knobby hint of an upper parietal barrier; peristome thickened, expanded only in direction of umbilicus, not reflected; aperture adnate to penultimate whorl; umbilicus narrow and deep, its edge covered by peristome.

Differential diagnosis. Tonkinospira crassicostata new species differs from all other Tonkinospira species by the strong ribs, the lack of spiral striation on the lower whorls, the knobby hint of an upper parietal barrier and the thickened peristome and adnate aperture. Tonkinospira tomasini is larger, has a less adnate peristome, weaker sculpture and a more sigmoid umbilicus. See also under T. triangulata new species.

Etymology. The specific epithet refers to the strong ribs of Tonkinospira crassicostata new species.

Figures

Fig. 3. Tonkinospira chytrophora (Mabille, 1887), MNHN-IM-2000-32862 (lectotype).