A geometric treatment of the Lagrangian path integral for gauge theori
es based on a closed algebra is presented. A general expression that e
nsures gauge invariance of the path integral is obtained for the funct
ional measure. The integral over gauge orbits is considered as an inte
gral over hypersurfaces in the configuration space that are specified
by an arbitrary gauge condition. A special form of the measure in the
integral over the orbits is constructed by analogy with the decomposit
ion of the determinant of the 4-metric in canonical gravity. The resul
ts are discussed briefly in the context of operator ordering and quant
um anomalies.