Pseudopomatias prestoni Páll-Gergely, 2015

Páll-Gergely, Barna, Fehér, Zoltán, Hunyadi, András & Asami, Takahiro, 2015, Revision of the genus Pseudopomatias and its relatives (Gastropoda: Cyclophoroidea: Pupinidae), Zootaxa 3937 (1), pp. 1-49 : 27

Pseudopomatias prestoni Páll-Gergely , n. sp.

Figs 10A –B

Diagnosis. A small to medium sized, turriform species with conspicuously thickened ribs (tubercles) around the umbilicus.

Description. Shell greenish-yellowish, rather turriform in shape, widest at its base; the 5.75–6.5, rather flat whorls are separated by shallow suture (although the apical whorls can be more bulging with deeper suture); protoconch consist of about 1.5 whorls; the sculpture of the first 0.75–1 whorl is granulated, matt, ribs are not detectable; after that it becomes regularly ribbed; teleoconch regularly, finely ribbed with extremely fine spiral lines; the ribs are denser on the apical whorls and become more widely-spaced and lower on the penultimate and last whorls; ribs disappear on the last half whorl, where the very fine, spiral structure is better visible; umbilicus is surrounded by three to five white, radial knots, which represent the lower halfs of the ribs; behind the apertural rim there are one to three (in most cases two) whitish thickenings, usually one of them is much thicker than the others; these thickenings are “full-length” ribs near the aperture but became visible only near the umbilicus in posterior direction (= radial knots around the umbilicus); aperture round, with the parietal part being straight; columellarparietal transition slightly, parietal-palatal transition sharply angled; apertural rim slightly reflexed, relatively thin, whitish, with having a slimmer inner and a wider, thicker outer circle; parietal callus well-developed.

Measurements (in mm). H: 5.8–7.8, D: 3.1–3.7. (type series, n=3); H: 8.6–9.4, D: 3.7–3.8 (NHMW 109194, n=2).

Differential diagnosis. P. prestoni n. sp. can be distinguished from any other congeneric species by the strong tubercles on the base of the shell. The most similar species in terms of shell shape and aperture morphology is P. harli n. sp., which is, addition to the smooth periumbilical region, usually smaller and has more bulging whorls. P. pleurophorus possesses a more tumid, wider shell without spiral sculpture between the ribs. See also Table 5 .

Material: Damsang Peak, Sikkim, W Bhutan, leg. Godwin-Austen, NHMUK 20130423.1 (holotype), NHMUK 20130423.2–46 (46 paratypes), (mixed sample with P. harli n. sp.); Himalayas, E. R. Sykes coll., Acc. no. 1825, NHMUK 20130413.3 (one paratype; mixed sample with P. cf. himalayae and P. harli n. sp.); Damsang Peak, W Bhutan, Godwin-Austen coll., NHMUK 20130421/1 paratype (mixed sample with P. ha r l i n. sp.); Rissom Peak, Sikkim, NHMUK 1903.7.1.3469/7 paratypes (mixed sample with P. h ar l i n. sp.); Damsang Peak, Sikkim, leg. Godwin-Austen, coll. A.J. Peile, Acc. no. 2242, NHMUK 20130422/3 paratypes; Indien, Dr. Stoliczka coll, 1880, NHMW 109194/2 (unusually tall shells with strong ribs, not paratypes; mixed sample with P. him al ayae: NHMW 109195 and P. abletti n. sp.: NHMW 109196).

Type locality. Damsang Peak, Sikkim, W Bhutan.

Etymology. This new species is dedicated to Hugh Berthon Preston (1871–1945), British malacologist, who worked on the genus Pseudopomatias at the beginning of the 20th Century, but did not publish his results.

Distribution. According to original labels, the species is known from Sikkim state ( India) only. See also Fig. 2 and Table 3 .

Remarks. Two shells from " India " (NHMW 109194) have taller (6.8–9.4 mm), slimmer shell than the type series, and have more conspicuous sculpture, stronger ribs and spiral structure. In museum collections Pseudopomatias prestoni n. sp. was frequently in mixed lots with P. himalayae , P. harli n. sp, and once with P. abletti n. sp.

Figures

FIGURE 2. Different areas of north-eastern India mentioned in the text. See also Table 3. 1: Sikkim, 2: Aka Hills, 3: Garo Hills, 4: Khasi Hills, 5: Dafla Hills, 6: Abor Hills, 7: Naga Hills.

FIGURE 10. A. Pseudopomatias prestoni n. sp., holotype, NHMUK 20130423.1; B. P. prestoni n. sp., Indien, NHMW 109194; C. P. siyomensis Godwin-Austen, 1917, holotype, NHMUK 3406.03.7.1; D. P. himalayae, Himalaya, Darjiling, NHMUK 1860.6.27.32.1; E. P. himalayae, syntype, UMZC 102695; F. P. peguensis (Theobald, 1864), Pegu, Burmah, NMW. 1894.015; G. P. shanensis n. sp. holotype, NHMUK 1903.7.1.1631.1; H. P. reischuetzi n. sp., holotype, NHMUK 1903.7. 1.1549. 1. Photos: A, C – D, G – H: H. Taylor; B: J. Harl; E: J. Gundry; F: B. Rowson. Scale bars = 5 mm; the smaller one refers to the photos of the whole shell, the larger one refers to the photos showing the lateral and basal side of the shells.