Hydrachnidia Krantz, 1978 - water mites Superfamily Hygrobatoidea Koch, 1842 Family Hygrobatidae Koch, 1842 Genus Atractides Koch, 1837 1 Subgenus Atractides (Atractides) Koch, 1837 2 Subgenus Atractides (Maderomegapus) Lundblad, 1941 3 Subgenus Atractides (Polymegapus) Viets, 1926 4 Subgenus Atractides (Tympanomegapus) Thor, 1923