12. Hydraena (Hydraenopsis) formula Orchymont, 1932

Hydraena formula Orchymont, 1932: 655; Hansen, 1998: 43; Jäch et al., 2000: 256; Jäch et al., 2013: 54; Jäch & Skale, 2015: 142.

TL: Vietnam, Tonkin, Lac Tho nr Hoa Binh. TD: ISNB.

Distribution: India: Sikkim and West Bengal (Darjeeling). Elsewhere: China, Indonesia, Nepal, Singapore, and Vietnam.