The Pig-tailed Baboon 145 Skull of the Chacma 147 Skull of the Anubis Baboon 149 The Anubis Baboon 152 The Common Baboon 153 The Mandrill 156 Young Mandrill 157 Skull of the Mandrill 158 The Drill 160 The Black Baboon 161 The Skeleton of the Mandrill 162 A Group of Howlers 165 Bones of the Tail of the Howler 167 Section of Head and of Air Sac of the Howler--Upper Part of Breast-bone and Collar-bones of the Howler--Brain of the Howler 168 Yellow-tailed Howler and Young 169 The Caparro 170 Group of Spider Monkeys _To face page_ 173 Brain of the Spider Monkey 173 Jaw of the Spider Monkey--Hand of the Spider Monkey 174 The Coaita 176 The Chameck 177 The Black and Variegated Spider Monkeys 179 The Hooded Spider Monkey 180 The Brown Capuchin 181 The Cai 184 The Callithrix Amictus 188 Arm-bone of Owl Monkey 189 The Red-footed Douroucouli 190 Brain of Monk 192 The Monk 193 The Couxio 194 The White-headed Saki 196 The Common Marmosets 197 Hand-bones of Marmoset--Foot-bones of Marmoset 198 Deville’s Midas 201 Skull of Marmoset 202 Head of the Black Howler 205 Young Orangs 209