In this paper is studied the configuration of lines of curvature near a Whi
tney umbrella which is the unique stable singularity for maps of surfaces i
nto R-3. The pattern of such configuration is established and characterized
in terms of the 3-jet of the map. The result is used to establish an expre
ssion for the Euler-Poincare characteristic in terms of the number of umbil
ics and umbrellas.