Mesohippus, N. American Tertiary, 135
Mesonyx, N. American Tertiary, 134
Mesopithecus, Miocene of Greece, 115
Meyer, Dr. A. B., on reptiles and amphibia of New Guinea, 415
Microlestes, oldest European mammal, 160
Micromeryx, European Miocene, 120
Microsyops, N. American Tertiary, 133
Microtherium, European Miocene, 120
Middendorf, on extreme northern birds, 219
Migrating birds, in which region to be placed, 185