Pseudopomatias caligosus n. sp.

(Fig. 3)

TYPE MATERIAL. — Thailand. Mae Hong Son Province, 9.1 km from Ban Soppong towards Mae Hong Son, left side of road # 1095, 785 m a.s.l., 19°33.123’N, 98°11.694’E, leg. Hunyadi A., 09.II.2015., HNHM 100176 (holotype), HNHM 100442 (figured paratype), coll. HA (17 paratypes + 9 juvenile shells [not paratypes]), coll. PGB, 2 paratypes .

ETYMOLOGY. — The specific epithet caligosus (Latin: covered with mist) refers to the nickname of the Thai Province Mae Hong Son (“city of three mists”).

TYPE LOCALITY. — Thailand, Mae Hong Son Province, 9.1 km from Ban Soppong towards Mae Hong Son, left side of road # 1095, 785 m a.s.l., 19°33.123’N, 98°11.694’E.

DIAGNOSIS. — Shell medium sized to large for the genus, slender turriform with regular ribs, very fine spiral striation (mostly on the upper whorls), and a reflected peristome.

DIFFERENTIAL DIAGNOSIS. — This new species is most similar to P. peguensis (Theobald, 1864) in terms of shell size and the bulging whorls, but differs from that species in the less glossy shell, the much stronger ribs, and the reflected peristome. Pseudopomatias shanensis Páll-Gergely, 2015 also has less bulging whorls, a more

strongly expanded peristome and denser ribs with clearly visible spiral striation between them.

DISTRIBUTION. — This species is known from the type locality only.

DESCRIPTION

Shell off-white to yellowish, all examined shells covered in reddish soil; shell very slender turriform, widest at its base; the 8.5-9.25 (n = 5), strongly bulging whorls separated by deep suture; protoconch with 2.5 whorls, first c. 0.75 whorl very finely granulated; remaining whorls very finely, regularly ribbed; teleoconch also finely, regularly ribbed; ribs rather strong, with triangular cross section; upper whorls with very fine spiral and radial lines, visible only under strong magnification (Fig. 3F); spiral lines getting weaker and less regular on last c. 2 whorls (here area between ribs dominated by very fine radial lines, Fig. 3G); aperture rounded with very slightly angled columellar-parietal transition and slightly more sharply angled parietal-palatal transition; peristome whitish, expanded and strongly reflected; inner peristome protruding in some specimens, but the boundary between inner and outer peristomes usually hardy visible.

Operculum

Proteinaceous (“horny”), thin, flat (not concave); outer surface multispiral without elevated lamina; inner surface glossy, with a small, but elevated ventral nipple.

Radula (Fig. 3F)

Radula taenioglossate. Radular teeth arranged in v-shaped rows, each transverse row with seven teeth (2-1-1-1-2). Central (rachidian) tooth not constricted at its middle, with well-developed, slender, pointed central cusp and one smaller, pointed lateral cusp on each side; inner marginal (= lateral) teeth with four cusps, all pointed, central cusp being the largest; two outer marginal teeth with 4-4 slender, pointed cusps (except for the outermost cusp of outer marginal tooth, which is rather blunt triangular).

Measurements (in mm)

H = 9.7-12, D = 3.8-4.4 (smallest and largest shells measured).