any of a genus (Saimiri) of small, tropical, New World monkeys (family Cebidae) characterized by naked black skin around the nose and mouth, white fur around the eyes and ears, and a long tail that is not prehensile
See squirrel monkey in American Heritage Dictionary 4
noun
Any of several small, brightly colored arboreal monkeys of the genus Saimiri, widely distributed in South and Central American tropical forest regions, having a white face with black nose and mouth, short fur, and a long nonprehensile tail.