(sakis), a genus of platyrrhine monkeys of the family Cebidae. The body length is 30–48 cm, the tail length is 25–55 cm, and the weight reaches 1,600 g. The tail is nonpre-hensile, bushy, and pointed. The fur is thick and long, and in the hairy, or monk, saki (P. monachus) it forms a cowl covering the shoulders and head. There are two species, distributed in the Amazon Basin. Sakis live in small groups or, sometimes, in pairs. They feed on fruits, leaves, small mice, and small birds. One offspring constitutes a normal litter.