“Their marsupium is well developed, opens to the rear, and contains only 2 teats.”
“Members of this family have a well developed marsupium that opens anteriorly.”
“In some species of marsupials, females develop a pouch or marsupium in which the young are nursed.”
marsupial
A mammal of which the female has a pouch in which it rears its young, which are born immature, through early infancy, such as the kangaroo or koala, or else pouchless members of the Marsupialia like the shrew opposum.