Hydrachnidia Krantz, 1978 - water mites Superfamily Arrenuroidea Thor, 1900 Family Hungarohydracaridae Motaş & Tanasachi, 1959 1 Subfamily Hungarohydracarinae Motaş & Tanasachi, 1959 2 Subfamily Balcanohydracarinae Cook, 1967 [monotypic] 3 Subfamily Cubanohydracarinae Orghidan & Gruia, 1980 [monotypic]