La segmentation primitive des Acariens. - A description is given of the primitive segmentation of the two superorders of mites, after the example of representatives of two genera: Opilioacarus (Anactinotrichida: Opilioacarida) and Alycus (Actinotrichida: Actinedida). The groups are compared with each other; the similarities and the fondamental differences are signalized; and a table of the primitive segments and their appendages, etc. in the two superorders of mites is drawn up. The phylogeny of the primitive segmentation in higher developed groups of mites is treated in short.