Hoffmann’s titi monkey, Callicebus hoffmannsi
Oldfield Thomas described in 1908 Hoffmann’s titi monkey, based on a specimen that was collected in Santarem, Brazil. He describes the species as “a greyish species with light yellowish underside and hoary hands and feet; general colour of body above greyish brown with a subdued undertone of rufous; crown grizzled grey; cheeks, whole of the under surface, and inner side of limbs light yellowish or pale buffy, very different from the strong rufous of these parts in allied species. Arms and legs grizzled grey like the crown; hands and feet blackish grizzled with white, the results being a hoary-slate grey, tail black.
Its distribution is believed to be in Central Amazonia, Brazil, south of the Rio Amazonas in the states of Amazonas and Pará, from the right bank of Rio Canumã, to the left bank Rio Tapajós; south to the north (right) bank of Rio Sucundurí and north along the south bank of the Paraná do Urariá and Paraná do Ramos, east along the left bank of the Rio Andirá and the right bank of the Rio Uíra-Curupá south of the town of Parintins.