How to define a function space using a BoundaryMesh - disagreement between geometric and toplogical dimension

Hi,

I am trying to create a FunctionSpace on the boundary of a problem domain.

Specifically using BoundaryMesh as follows:

import dolfin as D

mesh = D.UnitCube(2,2,2)
print mesh.topology().dim(), mesh.geometry().dim()
V = D.FunctionSpace(mesh, 'N1curl', 1)

boundary_mesh = D.BoundaryMesh(mesh)
print boundary_mesh.topology().dim(), boundary_mesh.geometry().dim()
W = D.FunctionSpace(boundary_mesh, 'N1curl', 1)

The last statement gives an error:
RuntimeError: *** Error: Geometric dimension of the UFC dofmap and the Mesh do not match.

This also happens when I try to use other types of elements. I assume this is because there are a difference between the topological and geometric dimension.

Is this correct? Or is this an error?

Renier