Hydrachnidia Krantz, 1978 - water mites Superfamily Arrenuroidea Thor, 1900 Family Athienemanniidae Viets, 1922 Subfamily Notomundamellinae Cook, 1986 1 Genus Davecookia Harvey, 2003 2 Genus Janszoonia Smit, 2007 3 Genus Mellamunda Harvey, 1988 4 Genus Notomundamella Cook, 1986 5 Genus Phreatohydracarus Tanasachi & Orghidan, 1955