Hydrina Robineau-Desvoidy, 1830: 794 (feminine). Type species: Hydrina vernalis Robineau-Desvoidy, 1830 (= Notiphila guttata Fallén, 1813), subsequent designation, Coquillett, 1910.
Hyadina Haliday in Curtis, 1837: 282 (feminine). [Published in synonymy, first used for a taxon by Haliday, 1839] Type species: Notiphila guttata Fallén, 1813, subsequent designation, Westwood, 1840.
Ephydrosoma Lioy, 1864: 1103 (neuter). Type species: Ephydra rufipes Meigen, 1830, monotypy.
Diagnosis. Hyadina is distinguished from other genera in the subfamily Ilytheinae by the following combination of characters: orbital setae very small or absent; both vertical setae present, if outer absent then lateral margins of scutellum densely velvety microtomentose. Thorax without large postsutural dorsocentral setae; anterior notopleural seta absent or very small, posterior notopleural seta large. Wing costa extended to vein M; second costal section less than twice as long as third costal section. Abdominal tergite 4 nearly as long as tergite 5, neither conspicuously punctate (Clausen 1983, Mathis and Zatwarnicki 1998).