Tonkinospira crassicostata Páll-Gergely & Grego, 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 : 520-525

Tonkinospira crassicostata Páll-Gergely & Grego , new species

( Fig. 4 )

Type material. Holotype (H: 1.84 mm, D: 1.37 mm, Fig. 4 ) ( HNHM 104403 ), Laos, Khammouane Province, 500 m SE of village Ban Phondou, 17°31.763′N, 104°53.792′E, coll. J. Grego, 13 February 2017.

Type material. Holotype (H: 1.56 mm, D: 1.26 mm, Fig. 5 ) ( HNHM 104404 ), Vietnam, Ðà N ẵng, Ngũ Hành SƠn, Thái SƠn, environment of Chùa Quán Th ế Äm, 7 m a.s.l., 15°59.944′N, 108°15.334′E (locality code: 2019/25a), coll. A. Hunyadi, 11 February 2019; 51 Paratypes + 13 broken shells (not paratypes), coll. HA, same data as preceding.

Diagnosis. A medium sized Tonkinospira species with a high conic shell, dense spiral striation, and a peristome that is not adnate to penultimate whorl.

Description. Shell medium sized for the genus; high conic with rounded body whorl; shell transparent, colourless; 5 whorls, regularly increasing; suture deep; penultimate whorl widest from standard apertural view; protoconch consists of 1.5 whorls, finely rugose, and densely, strongly spirally striated; teleoconch with irregular, rough radial growth lines, and dense, rather regular spiral striation creating a reticulate surface texture, ca. 22–23 in number in the middle shell line from apertural view; aperture strongly oblique to shell axis, turning downward in alignment with the penultimate whorl in lateral view; aperture ovate-subquadrate; peristome slightly expanded, not reflected; aperture not adnate to penultimate whorl; umbilicus narrow, not covered by peristome and is almost ½ the diameter of the base of the shell.

Measurements (in mm). H = 1.37–1.56, D = 1.2–1.36 (n = 3).

Differential diagnosis. Tonkinospira danangensis new species differs from T. pauperrima by the more accurately rounded whorls, shallower suture, and wider umbilicus. Tonkinospira triangulata new species has a comparatively larger aperture, more rapidly growing whorls and a narrower umbilicus.

Etymology. Named after the city of Ðà Nẵng, where the type locality is located.

Figures

Fig. 4. Tonkinospira crassicostata Páll-Gergely & Grego, new species, HNHM 104403 (holotype).

Fig. 5. Tonkinospira danangensis Páll-Gergely & Hunyadi, new species, HNHM 104404 (holotype).