Investigation of a degenerate case of the motion of the Kovalevskaya top

A complete study of the initial conditions which correspond to the degenerate molion of the Kovalevskaya top is carried out in the case where $e_3=e_4=s_2$. We obtain new motions and give a geometric interpretation of them. It is shown, in particular, that the symmetry axis of the body in the first approximation is moving periodically describing a cardioid on a fixed sphere.