  We initiate the study of the generalized quaternionic manifolds by
classifying the generalized quaternionic vector spaces, and by giving two
classes of nonclassical examples of such manifolds. Thus, we show that any
complex symplectic manifold is endowed with a natural (nonclassical)
generalized quaternionic structure, and the same applies to the heaven space of
any three-dimensional Einstein-Weyl space. In particular, on the product $Z$ of
any complex symplectic manifold $M$ and the sphere there exists a natural
generalized complex structure, with respect to which $Z$ is the twistor space
of $M$.
