Laeocathaica pewzowi Moellendorff, 1899

Figs 2A, 3, 19D, 21, 42F, 47G, H

Laeocathaica pewzowi Möllendorff, 1899: 98, pl. 6, fig. 4, 4a; - Sturany 1900: 22, pl. 2, figs 25-28; - Wiegmann 1900: 115, pl. 3, fig. 104; - Möllendorff 1901: 302; - Gude 1902: 6; - Yen 1939: 150, pl. 15, fig. 40; - Schileyko 2004: 1686, fig. 2174A; - Chen and Gao 2004: 329, fig. 320 (an erroneous figure that should be a Laeocathaica odophora); - Páll-Gergely et al. 2022: 67, fig. 23C, D.

Laeocathaica (Laeocathaica) pewzowi - Zilch 1968: 174; - Richardson 1983: 78.

Museum material.

SMF 9084, lectotype; Wen-hsien, S-Gansu; Potanin 248, 661, 793, Slg. O. v. Möllendorff . SMF 9085, paratypes, four fms; same data as lectotype. SMF 24268, Hung-dan (= Hengdan) b. Wen-hsien; Slg. O. v. Möllendorff, ex Berezowski. ZIN RAS No. 4, " Aegista pewzowi Schalf." 2 fma, locality unknown, coll. Potanin, 1885-IX-8, det. Möllendorff .

New material.

HBUMM08452, 1 fms and 4 juvs, Shangdezhen [尚德镇], Wenxian, Gansu Province, near point (32.907414°N, 104.76994°E); 2020-VIII, coll. Chen, Z.-G.

Distribution.

Gansu: Wenxian (type locality).

Additional information of shell.

Protoconch is smooth and has no granules, perhaps caused by erosion or weathering. Teleoconch has rough ribs between which fine threads are present. Spiral grooves are absent throughout.

General anatomy.

Head with flat but distinct eversible head wart. Jaw arcuate, with four projecting ribs.

Anatomy of genital organs.

Penial sheath covering ~ 1/9 of penis. Penis tubular and distally thicker. Inside penis, ~ 4 high parallel pilasters on proximal 2/3, at proximal ~ 1/4 two weak pilasters fusing into one Y-shaped fork. Fine pilasters on distal end of penis merging into ~ 7 thin or thick folds. Vas deferens narrow throughout. Vagina between atrium and dart sac not elongated. Vagina between dart sac and insertion of bursa copulatrix duct ~ 1/2 length of dart sac. Dart sac ~ 2/5 length of penis. Accessory sac tiny, internally solid, inserting into dart sac at middle part, opening to dart chamber. Mucous glands four, each singly tubular or simply branched. Proximal accessory sacs two, of similar size and symmetrical, apically separated and ventrally touching, each distally with an opening leading to proximal dart chamber. Bursa copulatrix duct of even diameter. Bursa copulatrix long-ovate.

Remarks.

The species has the most common pattern of the dart sac apparatus of the genus, i.e., two equally- sized and ventrally touching proximal accessory sacs, each with an opening leading to the dart chamber; this has been observed in ten of the 21 species anatomically studied herein. This species can be immediately recognized by its particular shell morphology.