Which is not a pouched mammal a wombat or spiny anteater?

Both spiny anteaters (echidnas) and wombats have a pouch. Wombats are marsupials, like most pouched mammals. Echidnas are not marsupials, but monotremes. Monotremes are egg laying mammals. Echidnas have a pouch so they can carry the egg they lay and, once the egg hatches, the baby echidna.