The families Streptaxidae and Diapheridae (Gastropoda, Pulmonata) in Bhutan, with notes on some species occurring in Nepal and North-east India

The sister-families Streptaxidae and Diapheridae are reported from eastern Bhutan, with two and four species, respectively. The occurrence of the streptaxid Perrottetia theobaldi marks the northwestern limit of the genus Perrottetia. Gulella (Huttonella) bicolor is a widespread invasive species that might have its native range in Asia. Two of the four Sinoennea species that are reported from Bhutan, viz. Sinoennea bhucylindrica Gittenberger & Leda and Sinoennea nimai Gittenberger & Gyeltshen, are regarded as new to science. Perrottetia theobaldi, Sinoennea vara and maybe S. latens support the biogeographical link across the Brahmaputra between eastern Bhutan and the Khasi Hills in the Meghalaya state of India. Notes on three Sinoennea species occurring in the eastern Himalayan foothills, but not known from Bhutan, are added.