Boysidia (Boysidia) xiaoguanensis, Zhang & Chen & Zhou, 2014

Zhang, Wei-Hong, Chen, De-Niu & Zhou, Wei-Chuan, 2014, Two new species of the genus Boysidia from China, with a preliminary discussion of its geography (Pulmonata: Stylommatophora: Pupillidae), Zoological Systematics 39 (4), pp. 570-575 : 573-574

4.2 Boysidia (Boysidia) xiaoguanensis sp. nov. ( Figs 6 ― 10 )

Holotype ( IZCAS TM 129969 ), collected from Xiaoguan (29°56 ʹ N, 109°20 ʹ E), Xuan'en, Hubei, China, 17 June 1984.

Paratypes, 40 specimens (20 adult shells were measured), collected from Xiaoguan (29°56 ʹ N, 109°20 ʹ E; IZCAS TM 129960 ― 129968 , 129970 ― 130015 ), Xuan'en , 17 June 1984 and Chengguan (30°02 ʹ N, 109°28 ʹ E; IZCAS TM 101767 ― 101681 ), Enshi , Hubei, China, 12 August 1985 .

Etymology. The name of the new species refers the type locality of the new species, Xiaoguan Town.

Size. Shell height 3.41 ― 3.61 mm (3.50 ± 0.11 mm), shell diameter 2.15 ― 2.20 mm (2.20 ± 0.14 mm), height of aperture 1.07 ― 1.14 mm (1.10 ± 0.07 mm), diameter of aperture 0.98 ― 1.08 mm (1.03 ± 0.08 mm). Holotype. Shell height 3.55 mm, shell diameter 2.20 mm, height of aperture 1.10 mm, diameter of aperture 1.05 mm,

Description. Shell small, slightly thick, lustrous, elongated, conic. Whorls 5.5 ― 6.5, moderately convex with high spire. Shell height about 1.59 ― 1.64 times of width. Shell color chestnut-brown becoming yellowish brown towards apex. Shell surface with oblique slender and dense growth lines, becoming weakened towards apex. Embryonic whorls numbered 1 ― 2, increasing slowly, smooth. Apex blunt. Sutures deep. Peristome separated from body whorl. Aperture elliptical, bell-formed, thick, slightly expanded and reflexed, slightly oblique to the left, with 4 teeth. Angular and parietal lamellae fused into one large elevated flake-shaped tooth (Par) reaching to the apertural margin, one long flake-shaped columellar tooth (Col) reaching to the apertural margin, one large moderately elevated flake-shaped upper palatal tooth (Upal) nearly reaching to the apertural margin, one slightly small moderately elevated flake-shaped lower palatal tooth (Lpal) deep within the aperture. Three plicate lines visible in the left side of the last whorl, one plicate line visible in umbilicus. Umbilicus slightly big, cavity-shaped. Columellar margin not covering umbilicus.

© Zoological Systematics, 39(4): 570–575

Habitat. The snail lives in limestone area, habits on the surface of limestone, in moist locality with bryophyte and lichen; or lives in chink of rock, under fallen leaves and rotten branch.

Remarks. The new species is very close to Boysidia (Boysidia) xishanensis Chen & Wu, 1999 , but differs clearly by the shell characteristics. Shell of B. xishanensis (height 2.75 mm, diameter 1.5 mm) is smaller than that of B. xiaoguanensis sp. nov. (height 3.55 mm, diameter 2.20 mm). Four apertural teeth are bearing in both species. But B. Xishanensis has a slightly large, nipple-shaped infrapalatal tooth, without the lower palatal tooth, and its upper palatal tooth is smaller than that of B. xiaoguanensis sp. nov. Moreover, the umbilicus is small in B. xishanensis , but slightly big in B. xiaoguanensis sp. nov.

Among Chinese species of Boysidia (Boysidia) , B. (B.) taibainensis Chen & Wu, 1999 and B. (B.) huangguoshuensis Luo & Chen, 2000 also have four same kind apertural teeth, but the size and shape of teeth are different from the new species. B. taibaiensis has a flake-shaped, bilobed angular-parietal tooth, one small nipple-shaped upper palatal tooth and one medium size nipple-shaped lower palatal tooth. Angular-parietal tooth and columellar tooth of B. huangguoshuensis are large and flake-shaped, and upper and lower palatal teeth are small and nipple-shaped.

Funding This research was supported by the National Natural Science Foundation of China (31260506, 31372162) and Natural Science Foundation in Fujian Province (2012J01063).

© Zoological Systematics, 39(4): 570–575

Figures

Figs 6―10. Boysidia (Boysidia) xiaoguanensis sp. nov. 6. Apertural view. 7. Right-lateral view. 8. Left-lateral view. 9. Umbilical view. 10. Aperture enlarged. Scale bars: 6―9=1mm, 10=0.5mm. Abbreviations: Par=parietal tooth; Col=columellar tooth; UPal = upper palatal tooth; LPal =lower palatal tooth.