Bensonella anguloobtusa (Inkhavilay & Panha, 2016)

Figs 6B, 7A, 13G

Paraboysidia anguloobtusus Inkhavilay & Panha in Inkhavilay et al. 2016: 215-217, figs 2d-f, 4b. Type locality: Kao Rao Cave, Vieng Phouka District, Luang Namtha Province, Laos. Inkhavilay et al. 2019: 61, fig. 26f.

Material examined.

Monastery, Ywangan Township, Taunggyi District, Shan State, Myanmar (locality code SH2; 21°13'43.3"N, 96°33'19.2"E): CUMZ 14398 (1 shell; Fig. 7A); CUMZ 14399 (87 shells); CUMZ 14400 (12 shells; Fig. 13G; measured); CUMZ 14401 (1 shell; Fig. 6B) .

Description.

Shell concave-conical, spire high, yellowish brownish in colour, and 4½ -5 convex whorls. Shell height 1.7-2.1 mm and shell width 1.5-1.7 mm. Apex blunt; protoconch ~ 1½ whorls with wrinkled roundish pits and spiral ridges. Teleoconch with wrinkles, irregular growth lines, and very fine, dense, inconspicuous spiral striae; suture well impressed and deep. Last whorl convex, very slightly shouldered. Aperture subrectangular with eight or nine apertural barriers. Peristome thickened and little expanded, cervical crest absent; lip pale yellowish to brown. Parietal lamella strongly developed, robust, broadly blunt and starting deeper inside aperture than angular lamella; infraparietal lamella very small and sometimes absent. Angular lamella strong and low, as well as long and sinuous upon reaching peristome, increasing in height deeper inside aperture. Palatal tubercle strongly developed with triangular shape. Upper palatal plica long and very thin; interpalatal plicae and lower palatal plicae approximately same size, large and long, tubercle-like. Columellar lamella large, strong, and horizontal; subcolumellar lamella bears small, robust fold. Umbilicus perforate, ~ 1/4 of shell width, rounded and deep.

Distribution.

This species is currently known from the type locality in Luang Namtha Province, Laos. In the recent survey, individuals were collected from the limestone outcrops in Shan State, Myanmar.

Remarks.

This is the first record of the species in Myanmar. The new specimens were collected ~ 480 km away from the type locality. Therefore, more of these snails can be expected to be found in the northeastern part of Myanmar and the northern part of Thailand. The specimens from Shan State all agree well with the type specimen in both shell form and apertural dentition. However, only a very small infraparietal lamella is present in some individuals.