  Two different four component Camassa-Holm (4CH) systems with cubic
nonlinearity are proposed. The Lax pair and Hamiltonian structure are defined
for both (CH) systems. The first (4CH) system include as a special case the
(3CH) system considered by Xia, Zhou and Qiao, while the second contains the
two-component generalization of Novikov system considered by Geng and Xiu.
