MODEL RIGID CR SUBMANIFOLDS OF CR DIMENSION-1

The following three classes of models of rigid submanifolds of higher type with CR dimension one are discussed: 1) A tube-like model that on ly depends on the real part of the holomorphic tangent coordinate; 2) a radial model that depends on the modulus of the holomorphic tangent coordinate and 3) a free model. The first and third models have a Lie group structure which is analyzed. A characterization of the hull of h olomorphy of the first two models is presented along with a partial re sult on the hull of holomorphy of the third.