Laeocathaica dityla Moellendorff , 1899

Wu, Min, Shen, Wang & Chen, Zhong-Guang, 2023, Land snail diversity in central China: revision of Laeocathaica Moellendorff, 1899 (Gastropoda, Camaenidae), with descriptions of seven new species, ZooKeys 1154, pp. 49-147 : 49

Laeocathaica dityla Moellendorff, 1899

Figs 2A , 3 , 13C-E , 14 , 41G, H , 45C, D

Laeocathaica dityla Möllendorff, 1899: 99, pl. 6, fig. 8; - Sturany 1900: 22, pl. 1, figs 4-6; - Wiegmann 1900: 121, pl. 3, figs 108-111; - Gude 1902: 6; - Yen 1939: 150, pl. 15, fig. 42; - Chen and Zhang 2004: 332, fig. 324; - Páll-Gergely et. al.: 57, fig. 16.

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

Museum material.

SMF 9086, lectotype. SMF 9087, 1 paratype. SMF 9088, 1 paratype. ZIN RAS No.1, 1 fms.

New material.

HBUMM00532, 2 juvs; Xinglongcun [兴隆村], Zhongzhaixiang [中寨乡], Wenxian, Gansu Province, near point (33.232415°N, 104.419075°E); 1998-V-19, coll. Chen, D.-N. and Zhang, Guo-Qing [张国庆] HBUMM00698, 1 fma and several juvs, 1 fma dissected; Daigusicun [代古寺村], Diebuxian [迭部县], Gansu Province, near point (34.004495°N, 103.940717°E), 1998-V-10, coll. Chen, D.-N. and Zhang, G.-Q. HBUMM05644, 4 fma and several fms; Jiaogongzhen , Wudu, Gansu Province (33.57°N, 104.64°E), broken limestone rocks, 2006-X-02, coll. Liu, J.-M. and Zheng, W. HBUMM05674, 1 fms; eastern bank of Bailongjiang [白龙江], Lianghekou [两河口], Dangchangxian [宕昌县], Gansu Province, near point (33.697332°N, 104.493015°E); limestone; 2006-X-02, coll. Zheng, W. and Gao, L.-H. HBUMM05685, 1 fma and 1 juv; western bank of Bailongjiang , Lianghekou , Dangchangxian, Gansu Province, near point (33.696791°N, 104.49129°E); limestone; 2006-X-02, coll. Zheng, W. and Gao, L.-H. HBUMM05710, 1 fms; Guantingzhen [官亭镇], Dangchangxian, Gansu Province, near point (33.82428°N, 104.538282°E); limestone hills, along 212 Guodao; 2006-X-3, coll. Zheng, W. and Liu, J.-M. HBUMM08449, 3 fms; Shijiba , Wenxian, Gansu Province, near point (33.067582°N, 104.457685°E); 2020-VIII, coll. Chen, Z.-G.

Distribution.

Gansu: Wenxian, Diebuxian, Dangchangxian, Zhouquxian (type locality).

Additional information of shell.

Tiny, low and sparsely arranged granules (~ 10 µm) on the smooth protoconch are present but difficult to be observed because of erosion or weathering. Spiral grooves are absent throughout the shell. On teleoconch the growth lines are not observed except on the part just following the protoconch.

General anatomy.

Eversible head wart present but not prominent. Jaw arcuate, with four or five projecting ribs.

Anatomy of genital organs.

Penial sheath rather short, covering ~ 1/8 of penis. Penis tubular and equally thick. Inside penis, two penial internal pilasters forming one Y-shaped fork at proximal 1/2 of penis, accompanied with another two thicker pilasters. Distal 1/2 of penis occupied by numerous isolated minute diamond-shaped papillae. Vas deferens narrow throughout. Vagina between atrium and dart sac not elongated. Vagina between dart sac and insertion of bursa copulatrix duct approximately as long as dart sac. Dart sac ~ 1/2 length of penis. Love dart ~ 4 mm long, apically 2-bladed and then rounded. Accessory sac small but distinguishable from outside, internally empty but spatially narrow, inserting into dart sac medially, opening to distal dart chamber. Mucous glands two (HBUMM00698-spec.2, spec.3) or three (HBUMM00698-spec.1), each a single tube. Proximal accessory sacs two, dorsally and ventrally touching, without internal pilasters, each with an opening leading to dart chamber near its opening. The right proximal accessory sac somewhat larger and with thicker wall than the left one. Bursa copulatrix duct basally slightly expanded. Bursa copulatrix ovate.

Remarks.

This species has a very unique shell, but the anatomy of the terminal genitalia coincides with those of the congeners.

Figures

Figure 2. A distribution map of all known species of Laeocathaica Moellendorff, 1899 except L. anceyi (Moellendorff in Ancey, 1889), L. hisanoi Pall-Gergely, 2022, and L. leucorhaphe Moellendorff, 1899 whose precise localities are not known; white dots: the localities where no Laeocathaica species was ever found B distribution of the new species described in this paper, yellow dots: L. qingchuanensis Wu, sp. nov., green dot: L. zhengpingliui Wu, sp. nov., brown dots: L. parapolytyla Wu, sp. nov., white dot: L. qiminglii Wu, sp. nov., pink dot: L. cheni Wu, sp. nov., blue dots: L. qishilii Wu, sp. nov., orange dots: L. nordsiecki Wu, sp. nov. C distribution of L. carinifera (H. Adams, 1870) (green dots), L. qingchuanensis Wu, sp. nov. (yellow dots), and L. stenochone Moellendorff, 1899 (blue dots) D distribution of L. amdoana Moellendorff, 1899 (green dots), L. distinguenda Moellendorff, 1899 (pink dots), and L. tropidorhaphe Moellendorff, 1899 (blue dots) C equivalent to the larger box in (A), B, D equivalent to the smaller box in (A).

Figure 3. Distribution map of Laeocathaica dityla Moellendorff, 1899 (green dots), L. odophora Moellendorff, 1899 (pink dots), L. pewzowi Moellendorff, 1899 (white dots), L. phaeomphala Moellendorff, 1899 (blue dots), L. polytyla Moellendorff, 1899 (yellow dots), L. potanini Moellendorff, 1899 (red dots), and L. prionotropis Moellendorff, 1899 (orange dots). Range of the map is defined by the rectangle in the thumbnail.

Figure 13. A, B Laeocathaica dejeana (Heude, 1882) A SMF 23919, lectotype B NHMUK 1902.5.13.1 - 2 C-E L. dityla Moellendorff, 1899 C SMF 9086, lectotype D SMF 9087, paratype E HBUMM 00698 - spec. 1.

Figure 14. Genital anatomy of Laeocathaica dityla Moellendorff, 1899, HBUMM 00698 - spec. 1 A general view B ventral view of dart sac apparatus C cross-section of dart sac at the position arrowed in (A) D left view of dart sac apparatus. Abbreviations: AS - accessory sac; At - atrium; BC - bursa copulatrix; BCD - bursa copulatrix duct; DS - dart sac; DtC - a chamber containing love dart; Ep - epiphallus; FO - free oviduct; MG - mucous glands; P - penis; PAS - proximal accessory sac; PO - opening of proximal accessory sac leading to dart chamber; PR - penial retractor muscle; PS - penial sheath; Va - vagina; VD - vas deferens. Asterisk * indicates the opening of proximal accessory sac.

Figure 41. Internal view of penis A, B Laeocathaica amdoana Moellendorff, 1899, HBUMM 05640 - spec. 1 A general view B proximal penis C L. filippina (Heude, 1882), HBUMM 04166 - spec. 1, general view D, E L. distinguenda Moellendorff, 1899, HBUMM 05436 - spec. 1 D general view E proximal penis F L. carinalis Chen & Zhang, 2004, HBUMM 08300 - spec. 1, general view G, H L. dityla Moellendorff, 1899, HBUMM 00698 - spec. 1 G general view H proximal penis. Arrows indicate the position where two penial internal pilasters fuse into one distal pilaster.

Figure 45. SEM micrographs A, B Laeocathaica potanini Moellendorff, 1899, HBUMM 00633 A protoconch B teleoconch C, D L. dityla Moellendorff, 1899, HBUMM 00698 C protoconch D teleoconch E, F L. qingchuanensis Wu, sp. nov., HBUMM 01179 a-spec. 6, paratype E protoconch F teleoconch G, H L. christinae (H. Adams, 1870), HBUMM 01251 a G protoconch H teleoconch I, J L. carinifera (H. Adams, 1870), HBUMM 04162 I protoconch J teleoconch K, L L. polytyla Moellendorff, 1899, HBUMM 05437 K protoconch L teleoconch.