The epicuticle's the outermost portion of the exoskeleton of an insect (and various other arthropods); its exact composition and structure may differ somewhat among different taxa, but certain aspects can be generalized:* It's secreted by the epidermis, and's deposited on top of the procuticle via pores that pass outwards through the procuticle from the epidermal cells. It contains no chitin, and's itself arranged in layers. The layers typically consist of an inner epicuticle, an outer epicuti… (More on Epicuticle)