Bradybaena virgo mongolia Wang & Zhou

Wang, Pei, Xiao, Qiong, Zhou, Wei-Chuan & Hwang, Chung-Chi, 2014, Revision of three camaenid and one bradybaenid species (Gastropoda, Stylommatophora) from China based on morphological and molecular data, with description of a new bradybaenid subspecies from Inner Mongolia, China, ZooKeys 372, pp. 1-16 : 9

Bradybaena virgo mongolia Wang & Zhou subsp. n. Fig. 2E; 4E

Etymology.

For the type locality, adjective.

Holotype.

(FJIQBC 18466) Shell height 6.5 mm, width 7.0 mm, height of aperture 3.5 mm, width of aperture 3.6 mm, October 5, 1982, collected from the type locality.

Paratypes 14 specimens.

(FJIQBC 18467-18471) and (IZCAS TM 126010-126018) Shell height 5.5-7.0 (6.4 ± 0.40) mm, width 6.4-7.5 (7.1 ± 0.25) mm, height of aperture 3.2-3.6 (3.4 ± 0.13) mm, width of aperture 3.3-3.7 (3.5 ± 0.16) mm, October 5, 1982, collected from the type locality.

Type locality.

The grassland of Zhalaiteqi, Inner Mongolia, China (46°43'59"N, 123°19'20"E).

Description.

Dextral, small sized, thin but solid, semi-translucent, lustrous, globular. Whorls 6 on average, with conical spire. Shell light yellow or white in color, with some dense and well-developed growth lines. Spiral lines on body whorl weak. Apex sharp. Suture deep. Last whorl constricted, expanded towards the base, convex, comprising about 3/4 of shell high. Aperture elliptical. Peristome reflected, with white, thickened callus inside. Inner lip and columellar lip reflected, partly covering umbilicus. Umbilicus narrow, deep.

Reproductive system.

Penis long. Flagellum absent. Penis retractor muscle slender, moderately long. Vas deferens moderately long. Oviduct short and thick. Vagina short. Dart sac inflated, thick. Accessory sac small. Two mucus glands. Pedunculus of bursa copulatrix slender, but not long. Bursa copulatrix oval.

Ecology.

The snail usually lives on damp pastures, especially in tall and dense grass, i.e., Achnatherum splendens . However, it is difficult to collect this animal because of serious grassland degradation in Inner Mongolia.

Remark.

The new subspecies resembles Bradybaena virgo virgo in morphology, but the two subspecies can be differentiated by the following characteristics: (1) The subspecies mongolia has a smaller shell (shell height 5.5-7.0 mm, width 6.4-7.5 mm) than Bradybaena virgo virgo (shell height 12.0 mm, width 13.5 mm), (2) it has two mucus glands instead of one in the nominate form, and (3) its umbilicus is wider (about 1/9 of the shell width) than in the nominate form (about 1/12 of the shell width).