Cebidae

Cebidae (suborder Simiiformes, superfamily Ceboidea) A family (perhaps artificial) that comprises the New World monkeys. They lack cheek pouches, and the nostrils are separated and face laterally. The gait is quadrupedal but some use a form of brachiation. Some have prehensile tails. The family includes Aotus species (night monkey, owl monkey, or douroucoulis) which are nocturnal. They have eyes with pure rod retinas, and lack prehensile tails. They may be closer than any other monkeys to the ancestral anthropoid form. Capuchin monkeys (several Cebus species) dwell in the forest canopy, feed on fruit and insects, and have an elaborate social structure. Howler monkeys (Alouatta species) feed on leaves and often use the prehensile tail in locomotion. Spider monkeys (Ateles species) sometimes move by a form of brachiation, with the aid of their prehensile tails, using long swings and jumps. They dwell in the canopy in small or large troops, and feed on fruit and nuts. Cebids are found throughout the tropical Central and S. American forests. There are 11 genera, with about 55 species.