The Monkeys of the New World--How Distinguished from those of the Old--Their Division into Families--The First Family, THE CEBIDÆ, with Prehensile Tails--THE HOWLERS--Appropriateness of their Name--Where Found--General Description--THE YELLOW-TAILED HOWLER--Anatomical Peculiarities and Appearance of the Face--Other Members of the Family--THE BLACK HOWLER--Its Locality--THE WOOLLY MONKEYS--THE CAPARRO AND BARRIGUDO--First noticed by Humboldt--Peculiarities of the Skeleton--THE SPIDER MONKEYS--Seen by Humboldt in the Brazilian Forests--Remarkable Power of the Tail--Flexibility of the Limbs--Conformation of the Brain--Other Species--THE COAITA--Curious Stories of them in Captivity--THE CHAMECK--THE BLACK SPIDER MONKEY--Its Geographical Range--Its Position in Sleep--THE VARIEGATED SPIDER MONKEY--THE SAJOUS--THE CAIARÁRA--Observed by Bates on the Amazon--Other Varieties--THE BROWN SAJOU--THE CAPUCHIN SAJOU--Described by Brehm--Their Remarkable Dexterity and Cleverness--Diseases of Monkeys 164 CHAPTER XI. THE CEBIDÆ (_concluded_)--THE SQUIRREL MONKEYS--DOUROUCOULIS--SAKIS. General Description of the Second Division of Cebidæ--Without Prehensile Tails--THE SQUIRREL MONKEYS--Described by Buffon and Humboldt--Peculiarities of the Species--Anecdotes by Le Vaillant--A Tragic End--THE WIDOW MONKEY--Origin of the Name--THE ONAPPO--Its Nocturnal Habits and Peculiar Cry--THE DOUROUCOULIS, OR OWL MONKEYS--General Description of the Family--Peculiar Formation of the Arm-bone--THE THREE-STRIPED OWL MONKEY--Described by Humboldt and Bates--THE RED-FOOTED DOUROUCOULI--THE SAKIS--Remarkable Resemblance in the Face to Man--Structural Peculiarities--THE COUXIO--THE PARAUACÚ--THE MONK--Description of the Brain--Other Varieties of the Sakis--Anecdotes of them--THE BLACK-HEADED SAKIS--General Description 185 CHAPTER XII. THE MARMOSETS AND TAMARINS--HAPALE--MIDAS. The Dentition of the Genus Hapale, or the Marmosets, or Ouistitis--The Face--The Paw-like Hands and Feet--Their Claws--The Skull and Brain, and the Nature of the Diet--THE COMMON MARMOSET--Its Habits--THE CLOAKED MARMOSET--THE GENUS MIDAS--THE TAMARINS--Their Dentition--THE NEGRO TAMARIN--Its Habits--MIDAS ARGENTATUM--DEVILLE’S MIDAS--THE SILKY TAMARIN--Notes on the Arctopithecini in General 197 CHAPTER XIII. GENERAL REMARKS ON THE MONKEYS. The Classification of the Monkeys of the New World--The Geographical Distribution of the Genera--The Fossil Monkeys of the New and Old World and their Alliances--The Former Old Fauna of Europe, Asia, and Africa--The Resemblance of Monkeys to other Animals and Man 203 CHAPTER XIV.