Let K \mathcal {K} denote the class of all compact metric continua K such that there exists a monotone mapping from a compact metric irreducible continuum M onto an arc such that each point inverse is homeomorphic to K. It is shown that no connected 1-polyhedron other than an arc is an element of K \mathcal {K} , but that K \mathcal {K} contains certain locally connected continua.