A series of oribatid specimens of the family Pheroliodidae belonging to a new genus and new species, Malgacheliodes guillaumeti n. gen., n. sp. have been collected in Madagascar, in the Andringitra mountain, located in the southern third of the island. The adult and immature stasis are described and illustrated and a key of the family genera is proposed. Malgacheliodes n. gen. is close to Pheroliodes, but can be separated from the latter by a set of characters that justify the establishment of a new genus: eight pairs of genital setae, arranged in two rows; pedotectal tooth, custodial point and discidium present; trachea 1 vestigial; distal apophyse of tibia I with two hollows; seta d present. The new species is characterized by, in the adults: sensillus, a flattened club; ip half-circle shaped; epimeric borders not exactly corresponding with respective apodemes; half apodemes 2 and sj ending far from the plan of symetry; femora carenated, with tracheas. And in the immatures: trachea I present; sockets complete, well developped on tarsus, tibias and genu, already present on the larva; socket of femur IV visible from deutonymphal stase; ϕ1 and ϕ2 housed in two separated hollows from deutonymphal stase.
Acari, Oribatida, Pheroliodidae, Madagascar, new genus, new species.