These remains consist of, first, the head of Ctenomys antiquus, allied to the living Ctenomys Braziliensis; secondly, a fragment of the remains of a rodent; thirdly, molar teeth and other bones of a large rodent, closely allied to, but distinct from, the existing species of Hydrochoerus, and therefore probably an inhabitant of fresh water; fourth and fifthly, portions of vertebrae, limbs, ribs, and other bones of two rodents; sixthly, bones of the extremities of some great megatheroid quadruped.