A type of appendage that is characteristic of arthropods of the Crustacea. It forks from the basal protopodite to form two branches, the inner endopodite and the outer exopodite (see illustration). Each of these branches can be composed of either one or more segments. There are many variations on this generalized structure; the branches often possess highly specialized extensions—the epipodite (on the coxopodite), the exite (on the exopodite), and the endite (on the endopodite). Compare uniramous appendage.