THROUGH the discoveries in the Oligocene1 of the Fayûm Mœritherium and Palæomastodon have become famous as two of the earliest, and more or less direct, stages in the ancestry of the elephants. In restorations by various authors each of these animals has. been provided with a proboscis of less or greater length, as would befit a more or less remote ancestor of an elephant. As first announced by Dr. C. W. Andrews, to whom we are chiefly indebted for our present knowledge, Mœritherium does anticipate the Palaeomastodon type in the enlargement of the second pair of upper and lower incisors and in the general pattern of the grinding teeth. Since the wish is always father to the thought, and nothing is more to be desired than a primitive progenitor of the Proboscidea, it was altogether natural to place Mceritherium in or near the line of ancestry of the elephant, and in such ancestry, as a member of the Proboscidea, the animal has gone into general literature.