Plectotropis brevibarbis (Pfeiffer,1859)

Zhou, Wei-Chuan, Xiao, Qiong, Chen, De-Niu & Hwang, Chung-Chi, 2011, Plectotropis yonganensis sp. nov. (Gastropoda: Bradybaenidae) from China, with revision of two Chinese camaenid species (Gastropoda: Camaenidae), Zootaxa 2929, pp. 51-56 : 53-54

Plectotropis brevibarbis (Pfeiffer,1859)

( Fig. 1 , F–I; Fig. 2 , B)

Helix brevibarbis Pfeiffer, 1859: 25 , 26, pl. 43, fig. 4; Pfeiffer, 1860: 28; Martens, 1867: 42; Pfeiffer, 1868: 332; Moellendorff, 1884: 328–329; Tryon, 1887: 221, pl. 52, figs. 1, 92, 93.

Helix (Ganesella) brevibarbis, Pilsbry, 1894: 169 .

Ganesella brevibarbis, Yen, 1939: 127 , pl. 13, fig. 15; Zilch, 1966: 202; Chen & Gao 1987: 112, fig. 143.

Type locality. Yangtze valley, China.

Material examined. Three syntypes ( BMNH); 11 in Tianmu Mountain of Zhejiang (May 1, 2007, 30°20ʹ21.02ʺN, 119°23ʹ58.33ʺE; FJIQBC 18256– 18266); 5 in Sanmen of Zhejiang, one of them is juvenile (May 8, 2007, 29°7ʹ73ʺN, 121°20ʹ12.23ʺE; FJIQBC 18267–18271); 16 in Yaolin, Tonglu of Zhejiang (May 25, 2008, 29°53ʹ7.90ʺN, 119°32ʹ8.59ʺE; FJIQBC18272–18287).

Shell. Sized medium, 13.5 mm in height, 16 mm in width, high conical, thin, transparent but solid. Whorls 7 1/2, growing regularly, slowly, slight convex on upper side, flat on base. Spire high. Color of shell white with thin, red brown bands on periphery. Periphery with acute keel. Peripherical hair present, short, triangular, ease to worn off when matured.

Surface of shell with delicate, dense and oblique growth lines staggered with dense, fine spiral lines. Aperture semicircle. Peristome thin and sharp, reflected. Columellar lip short, reflected, hardly covered umbilicus. Inner lip with white and thin callus. Umbilicus open, small, deep.

Reproductive system. Penial sized medium, about 12 mm in length, constricted at 1/3 and 2/3. Penis sheath short, about 1/6 of penis. Epiphallus short, a little longer than penial sheath, lightly expanded. Flagellum the same length as epiphallus, slightly expanded at base, with a slender tip. Penis retractor muscle slender and short. Vas deferens slender, about 20 mm in length. Oviduct thick, medium sized, lightly expanded at distal part. Pedunculus of bursa copulatrix expanded at base, gradually slender towards bursa copulatrix. Bursa copulatrix oblong-oval. Dart sac sized medium, elongated oval; accessory sac small and round. Mucus glands inserting laterally on accessory sac, two branches, and one of them bifurcate.

Habitat. The three collection sites, Tianmu Mountain of Linan, Tiantai Mountain of Sanmen and Yaolin, Tonglu in Zhejiang are Karst landform. The snail prefers shaded and damp forest. It is also found plentiful on the wall of historical temple. The egg is round and white, found in moist and soft topsoil or under the stone.

Remark. The shell morphology of the dissected samples agrees with the type specimens. This species was considered as a Ganesella because of its high-conical shell and angulated periphery without hairs that is worn off on syntypes. However, the present new conchological and anatomical evidences showed that the keeled periphery of shell has hairs and its reproductive system has a dart sac, an accessory sac and mucus glands, so we assign it in the genus Plectotropis .

Figures

FIGURE 1. Map of sampling sites and photographs of shells. A, Sampling sites of Fujian and Zhejiang, China. Square—type locality for Plectotropis yonganensis sp. nov.; Circles—sites with Satsuma stenozona; Triangles—sites with Plectotropis brevibarbis; B – E, Photographs of Satsuma stenozona from the National Forest Park of Fuzhou, China. B, C, D, (FJIQBC 18220), E (FJIQBC 18237); F – I, Photographs of Plectotropis brevibarbis. F, H, I, (FJIQBC 18256) from Tianmu Mountain, Zhejiang, China. G, (FJIQBC 18271) from Sanmen of Zhejiang, China, showing peripherical hairs; J – M, Photographs of Plectotropis yonganensis sp. nov. from Stone Forest, Yongan, Fujian China. J, L, M (FJIQBC 181201) holotype, K, (FJIQBC 181205) paratype, showing peripherical hairs.

FIGURE 2. Reproductive system. A, Satsuma stenozona from Drum Mountain, Fuzhou, China (FJIQBC 18245); B, Plectotropis brevibarbis from Tianmu Mountain, Zhejiang, China (FJIQBC 18226); C. Plectotropis yonganensis sp. nov. from Stone Forest, Yongan, Fujian China (FJIQBC 181219). AG: albumen gland; E: epiphallus; F: flagellum; HD: hermaphroditic duct; P: penis; PR: penis retractor muscle; BC: bursa copulatrix; PBC: pedunculus of bursa copulatrix; VD: vas deferens; S: stylophore or dart sac; AS: accessory sac; MG: mucus glands.