  We study the motion of stars in a star cluster which revolves in a circular
orbit about its parent galaxy. The star cluster is modelled as an ellipsoid of
uniform spatial density. We exhibit two 2-parameter families of self-consistent
equilibrium models in which the velocity at each point is confined to a line in
velocity space. We exhibit the link between this problem and that of a uniform
rotating ellipsoidal galaxy. With minimal adaptation, Freeman's bar models
yield a third family.
