The morphology and anatomy of Demodex folliculorum adults, and of selected members of the genus Demodex Owen, are detailed to the cellular and cell product level. Functional attributes of each anatomical system are discussed as ascertained from preserved and living material. Anatomical details for eggs, larvae, protonymphs, and nymphs are presented under each system (as for above) category. These structures are discussed, also, for functional properties. An extended synopsis is appended to provide an overview of structural, functional and developmental features of D. follicitlorum which should serve as analogues for other members of this genus.