Tetranychidae nouveaux de Madagascar (Sixieme note). - Eight new species of Tetranychidae occuring on malagasian wild plants are described and figured ~ Oligonychus leandrianae, O. chazeaui, O. pemphisi, Eotetranychus botryanthae, E. greveanae, E . xylopiae, E. rinoreae and Hellenychus (n. g.) bollandi. Sorne biological informations are given. The chromosome complement of three of these species has been studied in a separate paper.