The skull has the orbit almost completely shut off from the temporal fossa, and the lachrymal foramen is situated within the orbit. The pollex is sometimes vestigial or absent. The second digit of the pes has a flattened nail except in the Hapalidae, in which all the digits of the pes except the hallux are clawed.
The Anthropoidea are divided into five families:
1. Hapalidae or Marmosets.
2. Cebidae or American Monkeys.
3. Cercopithecidae or Old World Monkeys.
4. Simiidae or Anthropoid Apes.
5. Hominidae or Men.