THE MAMMALIA OR MILK-GIVERS, THE SIMPLEST SUCKLING MOTHER, THE
ACTIVE POUCH-BEARERS, AND THE IMPERFECT-TOOTHED ANIMALS 181
PICTURE-HEADING--Scene in the Triassic Period, with small
Marsupials _Microlestes_, whose remains are found earlier
than the toothed birds. (Restored conjecturally from the
nearest living representative, Myrmecobius.) In the water
large swimming reptiles.