The Lagothrix Monkeys, with their fine, furry coats, are found in the Ecuador district of the Amazons, but are unknown in Guiana and Eastern Brazil, and the species of the short-tailed Sakis are restricted to special districts; thus the Couxio is from Guiana, and does not pass the Rio Negro on the west, or the Amazon on the south. The white-skinned one is found on the Rio Negro, and the _B. rubicundus_ on the Upper Amazon, another species being found on the lower part of the same river. So it is with the other Sakis with long tails. The genus is found widely dispersed, but the species are restricted in their roaming. One is found, according to Wallace, on the north bank of the Upper Amazon, and another, with a red beard, only to the south-west of the Rio Negro. The genus Cebus has a very wide range in South America, so has the Squirrel Monkey group, for they are found on both banks of the Amazon and Rio Negro; but the white-collared species is found only on the Upper Rio Negro, and another on the Upper Amazon. The same author noticed the range of the Douroucoulis in the Amazon districts; one (_N. trivirgatus_) is found in Ecuador, and the Cat-like kind on the Upper Amazon. Equally restricted to limited districts were three kinds of Marmosets. Fossil remains of Monkeys have been found in the New World in the Brazils, which belong to the existing genera Cebus, Callithrix, and Hapale. The fossil Cebus is at least four feet in height, and the Callithrix was of a very large kind. The fossil Ouistitis are large and small. The geological age of the Brazilian fossils is probably about that of the last European deposits. Now, the remarkable part of this interesting story is, that in the olden time there was the same division of the Monkeys into those of the Old and of the New World. The Catarhini were then, as now, restricted to Europe, Asia, and doubtless to Africa; and the Platyrhini were only found in America, and moreover the resemblance of the old forms to the new is remarkable, the large size of the fossils being in keeping with what is known about the large dimensions of most of the old forms of life. Rütimeyer’s discovery in Switzerland of a fossil with bones like those of the Howler (Mycetes), and yet like a Lemur in structure, and of vast antiquity, carries us back to a time when a different distribution of animals prevailed. Then there were American-looking and Madagascar-looking things in Europe, and associated with them were Opossums and other creatures foreign enough to it at the present time. Nevertheless, this fact gives the hint of the origin of the American Monkeys from the Lemurs. Lately the fossil remains of a Lemur-like animal have been found in North America. In concluding this short notice of the extinct Monkeys, it must be remembered that in the days when there were those agreeable northern climates which made Greenland a land of flowers, Indian Monkeys lived in the dense woods of Greece, Central Europe, and Southern France.