  Cieliebak, Mundet i Riera and Salamon recently formulated a definition of
branched submanifold of Euclidean space in connection with their discussion of
multivalued sections and the Euler class. This note proposes an intrinsic
definition of a weighted branched manifold Z that is obtained from the usual
definition of oriented orbifold groupoid by relaxing the properness condition
and adding a weighting. We show that if Z is compact, finite dimensional and
oriented, then it carries a fundamental class [Z]. Adapting the construction of
Liu and Tian, we also show that the fundamental class [X] of any oriented
orbifold X may be represented by a map from Z to X, where the branched manifold
Z is unique up to a natural equivalence relation. This gives further insight
into the structure of the virtual moduli cycle in the new polyfold theory
recently constructed by Hofer, Wysocki and Zehnder.
