The previously unstudied collection of water mites from Madagascar conserved at the Muséum national d’Histoire naturelle, Paris, is investigated. Most of the 282 specimens, from 36 localities, were collected by J. Millot from stagnant waters at low altitude or on the High Plateau (surroundings of Antananarivo) during 1945-1955. Twenty-five taxa are identified, six of which recorded for the first time from Madagascar: the family Anisitsiellidae (Sigthoria nilotica Nordenskiöld, 1905); a genus and species new to science of the family Hygrobatidae; the genus Wuria (represented by a species new to science); the subgenera Bargena (Hydrachna) and Polyatax (Unionicola); and a species of the genus Eylais. Moramangabates pauliani n. gen., n. sp. is characterized by the absence of a suture line extending between the caudal apodeme on cx-4 and the glandular opening on this sclerite, 13 pairs of acetabula, and a central hump on the ventral surface of P-3. Wuria milloti n. sp. is characterized by larger pores between the medial margins of cx-3+4 and the facing margins of cx-2/3, acetabula arranged in rather distant rows, and stout palpal setae. First description of male and female adults is given for Hydrachna amplexa Koenike, 1898. The present state of knowledge is discussed from a zoogeographical point of view and necessities for future research are outlined. An updated list is included of all published information on the water mite fauna of Madagascar.
Acari, Hydrachnidia, diversity, zoogeography, freshwater fauna, Africa, new genus, new species.