Laeocathaica dolani (Pilsbry, 1934)

Figs 2A, 5C, 7, 42A, B, 47C, D, 52F

Cathaica (Laeocathaica) dolani Pilsbry, 1934: 16, pl. 3, fig. 4, 4a-c.

Cathaica dolani - Yen, 1938: 446.

Laeocathaica (Laeocathaica) dolani - Richardson 1983: 78.

Laeocathaica dolani - Chen and Zhang 2004: 335, fig. 328; - Páll-Gergely et al. 2022: 59, fig. 18A.

New material.

HBUMM00069, 6 fma, 3 fma dissected; Kangding, Sichuan Province, near 29.995149°N, 101.967008°E, 1964-VII-16, coll. Chen, D.-N. HBUMM08439, Manai [马耐], Badixiang [巴底乡], Danbaxian (= Danba), Sichuan Province, 31.11276°N 101.885295°E, 2008-VII-18, coll. Di, Zhi-Yong [邸智勇] .

Distribution.

Sichuan: Kangding, Danbaxian (type locality: Rumichangu).

Additional information of shell.

The shell is covered with radially arranged low scales of variable length (~ 25 - ~ 300 µm long) everywhere. The size (esp. length) of scales increase from protoconch to body whorl. Spiral grooves are absent throughout the shell.

General anatomy.

Eversible head wart present but not prominent. Jaw arcuate, with 3-6 projecting ribs.

Anatomy of genital organs.

Penial sheath covering ~ 1/4-1/3 of penis. Penis short, thick, distally expanded. Inside penis, two thick and prominent pilasters fusing into one Y-shaped fork at proximal 1/3-1/2 penis, accompanied with ~ 6 narrower or equally thick pilasters nearby. Pilasters on distal end of penis not merging into 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 approximately as long as penis. Love dart ~ 5 mm long, apically with cross-section rhombic. Accessory sac small, internally empty, inserting into dart sac at middle part, opening to distal dart chamber. Mucous glands two (HBUMM00069-spec.1-3), each complicatedly branched. Proximal accessory sac one, large, on right side of dart sac, with an opening leading to dart chamber near its opening. Bursa copulatrix duct basally slightly expanded. Bursa copulatrix elongate, ovate.

Remarks.

In Laeocathaica, Laeocathaica dolani is the only species with only one proximal accessory sac. In addition, this species is unique in the genus that it keeps periostracum scales throughout its lifetime.