In this article, two types of ellipsis with apparently quite different properties are accounted for in a derivational grammar model that employs both prosodic and syntactic tools for eliminating many of the surface dissimilarities. A central operation of this model is Copy α via Active Memory, adapted from work by Frazier and Clifton [Syntax 4 (2001) 1], whereby an initial conjunct of a coordinate structure is copied and later matched with the second (and subsequent) conjunct(s). Licensing of the ellipse at the right- and left-edges in the respective constructions occurs in a typical asymmetric c-command relation; in right-edge ellipsis, a syntactic feature, mapped to a focus feature in PF, is the licenser, while in left-edge ellipsis, the coordinating conjunction licenses the ellipse. In the derivation of both forms of ellipsis, cyclic rule application in the syntactic component precedes Copy α, i.e. derivation must precede conjunction, reflecting the surface-based properties of the ellipsis types. However, “deep” syntactic operations underlie the surface relations and play a crucial role in establishing the domains in which ellipsis operates. It will be shown that these are best accounted for in a derivational model.