Any one of numerous species of small South American monkeys of the genera Hapale and Midas, family Hapalidæ. They have long soft fur, and a hairy, nonprehensile tail. They are often kept as pets. Called also squirrel monkey.
- Any of various small clawed monkeys of the genera Callithrix and Cebuella, found in tropical forests of the Americas and having soft dense fur, tufted ears, and long tails.