  An upper bound on the first S^1 invariant eigenvalue of the Laplacian for
invariant metrics on the 2-sphere is used to find obstructions to the existence
of isometric embeddings of such metrics in (R^3,can). As a corollary we prove:
If the first four distinct eigenvalues have even multiplicities then the
surface of revolution cannot be isometrically embedded in (R^3,can). This leads
to a generalization of a classical result in the theory of surfaces.
