Tonkinospira raxajacki Páll-Gergely & A. Reischütz, 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 : 529

Tonkinospira raxajacki Páll-Gergely & A. Reischütz , new species

( Fig. 10 )

Type material. Holotype (H: 1.2 mm, D: 1.09 mm, Fig. 10 ) ( NHMW 113205 ), Laos, Khammouane Province, Tham Xienliab (cave), NE Thakhek , at the base of limestone rocks at the entrance of the cave, ca. 160 m a.s.l., approx. GPS coordinates: 17°27.213′N, 104°54.572′E (locality code: La.5), coll. Raxajack, S. & Reischütz, A., March 2010.

Paratypes: 1 paratype (MNHN-IM-2014-6406), South- Central Laos, Khammouane Province, ca. 32 km ENE of Thakhek ( Muang Khammouan), ca. 10 km WNW of Mahaxai, limestone, clay, black soil in limestone pockets, on and under rocks in dry secondary forest on steep N exposed slope under cliff, 180 m a.s.l., 17°26.957′N, 105°06.781′E (locality code: 1L07), coll. A. Abdou & I.V. Muratov, 24 November 2007 ; 1 paratype (coll. RE), Laos, Khammouane Province, Tham Pha Inh (cave), East of Thakhek , ca. 180m a.s.l., 17°27.687′N, 104°54.951′E, (locality code: La. 7), at the base of limestone rocks, coll. Raxajack, S. & Reischütz, A., March 2010 ; 10 paratypes (MNHN-IM-2014-6405), South-Central Laos, Khammouane Province, ca. 10.5 km E of Thakhek ( Muang Khammouan), on and under rocks, cave deposits, in secondary forest under entrance and in large cave on NE exposed steep slope, alt. 160 m, 17°24.340′N, 104°54.894′E (locality code: 25L07), coll. A. Abdou & I.V. Muratov, 09 December 2007 ; 1 paratype (coll. JG), Laos, Bolikhamsay Province, Nong Long 10 km SE of Lak Sao, Phou Phakô massif 2km E of the village, Spring and caves at NW foot of the massif, in front of the quarry, 18°6.894′N, 105°3.092′E, coll. J. Grego, 17 February 2017 .

Diagnosis. A small Tonkinospira species with an elongateconic shell, rounded body whorl, irregularly growing whorls, conspicuously deep suture, dense spiral striation, and a peristome that is not adnate to penultimate whorl.

Description. Shell small for the genus; elongate-conic with rounded body whorl; 4.25–4.5 whorls, irregularly increasing; suture remarkably deep; protoconch consists of 1.25 whorls, finely rugose, and densely, strongly spirally striated; teleoconch reticulated with irregular, rough radial growth lines, and dense, rather regular spiral striation, ca. 30 in number in the middle shell line from apertural view; aperture oblique to shell axis from lateral view; aperture ovate-subquadrate; peristome not or very slightly expanded, not reflected; aperture not adnate to penultimate whorl and slightly separated (ventral view) from the body whorl; umbilicus deep, slightly smaller than 1/3 the diameter of the base and not covered by peristome.

Measurements (in mm). H = 1.14–1.22, D = 1.09–1.21 (n = 4).

Differential diagnosis. The most similar species is Tonkinospira pauperrima , which is larger, has a more oblique aperture to the shell axis, a narrower umbilicus (the peristome partly covers the umbilicus), and has more regularly growing whorls.

Etymology. We dedicate this species to Somsamay Raxajack for enduring A. Reischütz for seven weeks during a Southeast Asia trip and in gratitude for the outstanding hospitality of his family’s native village Ban Pak Nam.

Figures

Fig. 10. Tonkinospira raxajacki Páll-Gergely & A. Reischütz new species, NHMW 113205 (holotype).