AN n-dimensional link of m components is a collection L = (K,, . . . . K,) of disjoint oriented locally Rat PL submanifolds of SncZ -each Ki homeomorphic to S”. L is a boundurp link if there exist disjoint oriented submanifolds (Seifert-surfaces) F,. . . . . F, of Sn+’ such that ?Fi = Ki(i = I.. . . , m). Boundary links are amenable to analysis by Seifer.t-matrix or homology-surgery techniques, especially when n > I. which often lead to concordance and isotopy classification results (see [6, 7, 14. IS. 203). In 1961 R. H. Fox expressed interest in 2-component boundary links because they could not bc distinguished from the trivial link by their Alexander polynomials. In 1965 N. Smythe [243 introduced a more general class of links with this property which he called hornoloy~ houndur~ links. These links were dcfincd as those which admit disjoint Scifert surfaces { Fi ); except 3f$ is allowed to consist of scvcral components, each an oricntcd longitude of some K,, but whose algebraic sum is + k’,. An alternative definition is given by Smythc in the context of an algebraic characterization of boundary links. A link L is a homology boundary link if and only if the quotient n/n,, where n is the fundamental group of the complement of L, is a free group. If, in addition, K/K, has a basis corresponding to a set of meridians of L, then L is a boundary link. (n, is the intersection of the lower central series {n,: n 2 11 of n, where A, = n and rrn+, = [IL x.1). Smythe gave an example of such a link which is not a boundary link, and in [9] several other examples are given. These examples are all ribbon links and, therefore, concordant to boundary links. Two problems can be stated: