Erhaia nainitalensis Davis & Rao, 1997

Gittenberger, Edmund, Leda, Pema, Wangchuk, Jigme, Gyeltshen, Choki & Bjoern Stelbrink,, 2020, The genera Erhaia and Tricula (Gastropoda, Rissooidea, Amnicolidae and Pomatiopsidae) in Bhutan and elsewhere in the eastern Himalaya, ZooKeys 929, pp. 1-17 : 8-11

Erhaia nainitalensis Davis & Rao, 1997 Fig. 9

Erhaia nainitalensis Davis & Rao, 1997: 276 ("India, Uttar Pradesh, Nainital District, Padampuiri"; " 29°23'N, 79°30'E ")

Erhaia chandeshwariensis Nesemann and S. Sharma, in Nesemann et al. 2007: 64, 78 fig. 4 ("Nepal, Central Zone, Kavre District, small forest stream, left tributary of the Chandeswari Khola upstream from Chandeshwari at Banepa"; the altitude is not indicated).

Material examined

(photos only). Holotype and 4 paratypes of Erhaia chandeshwariensis (NHMW 103315 and 103316).

Discussion.

According to Davis and Rao (1997: 277, legends to figure 2) the holotype of E. nainitalensis is 2.28 mm high. However, elsewhere in the same article ( Davis and Rao 1997: 279, table 1) the shell height of a single male animal is reported as 1.62 mm whereas 1.88-1.95-2.14 mm (minimum-mean-maximum) is indicated for five female snails. The difference in measurements between the single male and the five females might be indicative of sexual dimorphism. Shells of the species are also supposed to be “minute”, what is defined as 2.0 mm high or smaller ( Davis and Rao 1997: 275, 289, table 5). We suppose that the dimensions of the holotype of E. chandeshwariensis , i.e. H 1.94 mm, fall within the range of the measurements of E. nainitalensis . Three of the four paratypes of E. chandeshwariensis (NHMW 103316/4) are c. 1.9 mm high, whereas the fourth shell is damaged, missing the apical whorls. Davis and Rao (1997: 278, fig. 3) figure a smooth columella for E. nainitalensis , but mention (p. 289) a "discernable glassy thickening of the columella".

Judging the nominal taxa on the basis of photographs of shells and additional data in the literature, we conclude that in general shape and apertural characters, i.e. a narrow umbilical chink, a virtually smooth columella, and a thickened outer and inner lip, the holotype of E. chandeshwariensis cannot be distinguished from the shells of E. nainitalensis that are figured by Davis and Rao (1997: 277, figs 2A-F, 280, figs 4A-D). The fact that Davis and Rao (1997: 276) indicate 3¾ -4 whorls for E. nainitalensis , whereas Nesemann and Sharma (2007: 64) mention 3½ whorls for E. chandeshwariensis , might be due to different counting methods.

Family Pomatiopsidae Stimpson, 1865

Figures

Figures 2 - 10. Erhaia jannei sp. nov., holotype (2 H 2.25 mm) and paratype (3 H 2.02 mm). Bhutan, district Thimphu, W of Geneykha, brooklet with water powered prayer wheel, 2750 m a. s. l. Photos by J. Goud Erhaia pelkiae sp. nov., holotype (4 H 1.86 mm) and paratype (5 H 1.86 mm). Bhutan, district Thimphu, W of Geneykha, brooklet with water powered prayer wheel, 2750 m a. s. l. Photos by J. Goud Erhaia wangchuki Gittenberger, Sherub & Stelbrink, 2017. Shells from the type locality (6 H 1.98 mm) (7 H 2.03 mm); NBCB 1072. Bhutan, district Wangdue Phodrang, Gangchhu, Gangzetem brooklet, 2883 m a. s. l. Photos by J. Goud 8 Erhaia banepaensis Nesemann & S. Sharma, 2007, holotype (H 1.95 mm); NHMW 103319. Nepal, Central Zone, Kavre district, small forest stream, left tributary of the Chandeswari Khola upstream from Chandeshwari at Banepa. NHMW 9 Erhaia nainitalensis Davis & Rao, 1997, holotype of E. chandeshwariensis Nesemann & S. Sharma, 2007 (H 1.94 mm); NHMW 103315. Nepal, Central Zone, Kavre district, small forest stream, left tributary of the Chandeswari Khola upstream from Chandeshwari at Banepa. NHMW 10 Erhaia sugurensis Nesemann, Shah & Tachamo, 2007, holotype (H 1.95 mm); NHMW 104172. Nepal, Central Zone, Lalitpur district, Godawari, upper reaches of Sugure Khola forest stream, 1700 m a. s. l. NHMW.