Wau-wau Gibbon, ii. 154, 156 Weasel-like Sportive-Lemur, i. 80 weddelli, Hapale, i. 143 Midas, i. 143, 144; ii. 255 Weeping Çai, i. 216 Weeper Capuchin, i. 215 werneri, Cercopithecus, ii. 58 Werner's Guenon, ii. 58 White-cheeked Capuchin, i. 208 White-cheeked Gibbon, ii. 158 White-chested Titi, i. 161 White-collared Mangabey, ii. 38 Titi, i. 159 White-crowned Mangabey, ii. 39 White-eared Marmoset, i. 134 White-faced Lemur, i. 73 White-fronted Capuchin, i. 213, 215 White-fronted Marmoset, i. 134 White-footed Sportive-Lemur, i. 89 White-handed Gibbon, ii. 159, 160 White-handed Lemur, i. 74 White-headed Saki, i. 185 White-lipped Guenon, ii. 72 White-lipped Tamarin, i. 141 White-nosed Saki, i. 188 White-shouldered Marmoset, i. 133 White-tailed Guereza, ii. 98, 99 White-thighed Guereza, ii. 94 White-throated Capuchin, i. 206, 207 White-whiskered Coaita, i. 239 White-whiskered Spider-Monkey, i. 239 White Monkeys, ii. 115, 116 wolfi, Cercopithecus, ii. 79, 245 Wolf's Guenon, ii. 79 Woolly Avahi, i. 94 Woolly Monkeys, i. 204, 220, 221, 248 Woolly Spider-Monkeys, i. 204, 224, 225, 248 wurmbii, Papio, ii. 170 Pithecus, ii. 171 Pongo, ii. 170 Simia, ii. 171 xanthocephalus, Cebus, i. 209 Xanthochroi, ii. 208, 223 xanthomystax, Prosimia, i. 71 Yellow Baboon, i. 265 Yellow-handed Howler, i. 197 Yellow-tailed Tamarin, i. 144 zitteli, Microchærus, i. 116; ii. 241 Notes. [1] Specimens of _Anthropopithecus niger_ and _Gorilla gorilla_, in the Derby Museum, Liverpool, in which the permanent teeth have not yet developed, have the premaxillary suture quite obliterated. [2] The deformity known in the human skull as acrocephaly, which occurs in all races of men, and is due to the too early ossification of certain of its sutures, has been found in the Chimpanzee. [3] Huxley's "Natural History of the Man-like Apes," p. 5. [4] Living and fossil. [5] A form of _S. mitratus_. [6] _Midas rufiventer_, said to be from Mexico by Dr. Gray, is now believed to be Amazonian. Mr. Bates' statement that _Hapale pygmæa_ is found in Mexico (vol. i., p. 136) is erroneous, and no species of Marmoset is known from the Mexican Province. [7] _Chrysothrix entomophaga_ is stated by me (vol. i., p. 156) to inhabit Central America. The Squirrel-Monkey of Panama, however, is _C. oerstedi_, and _C. entomophaga_ must be restricted to the Brazilian Sub-region (cf. Alston, Biol. Centr. Amer. Mamm., p. 16). * * * * * Corrections made to printed text P. 29 'supra-orbital' corrected from 'supra-orbitral'. P. 31 (Macacus) 'assamensis' corrected from 'assameusis'. P. 29 'depredations' corrected from 'depradations'. P. 60 'Cercopithecus pygerithraeus' corrected from '... pygerithroeus' P. 84 'Cercopithecinæ' corrected from 'Cercopethecinæ'. P. 29 'Pays-Bas' corrected from 'Pays-Bays'.