Species Name: Cercopithecus diana
The Diana monkey is an Old-World primate found in the high-canopy forests of Liberia, Sierra Leone, and the western Ivory Coast. Diana monkeys get their name from the white crescent-shaped headband that resembles the crescent moon on the forehead of the Roman goddess Diana, protector of woodlands and wildlife.
Species Name: Mandrillus leucophaeus
The Drill is a primate in the Cercopithecidae family (Old-World monkeys), related to baboons and even more closely to mandrills. Like mandrills, drills are highly social animals that live in groups of around 20 individuals with multiple males and females, with one male dominating reproductive decisions.
Species Name: Chlorocebus dryas
The Dryas monkey, also called the Salonga monkey, Inoko, or Ekele is a little-known Old World primate only found in the Congo Basin and restricted to the Congo River's left bank. Unlike guenon monkeys, which make loud leaps and resounding calls, dryas monkeys move silently.
Species Name: Trachypithecus obscurus
Dusky langurs also known as spectacled langurs, spectacled leaf monkeys, and dusky leaf monkeys, are primarily found in the Malay Peninsula in Asia. White rings surrounding the deep, dark eyes give the species its alternative name, the spectacled monkey or spectacled langur, for a "bespectacled" look.
Suggested Reading: All Monkey Names