  We have performed for the first time in the literature a 2D structural
analysis on the barred lenticular and face--on galaxies NGC 4608 and NGC 5701.
The results indicate that these galaxies either have never had large disks or
their disks were almost completely destroyed by their strong bars, due to
secular evolution processes. We discuss these surprising conclusions checking
for signs of secular evolution, considering bar forming instabilities, and
suggesting, based on N-body simulations, a new mechanism to form bars in
spheroids, which includes non-spherical halos. Quantitative predictions from
our new mechanism are compared with those from other recent models for bar
formation and evolution.
