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3

a. B of Ateles - Squ-Wstl Callicebus
b. W of Saguinus - W of Leontideus

V. The ritualized postures and movements of different species are more varied, in basic structure, than their vocal patterns. Some species have relatively few ritualized postures and movements. This seems to be the primitive condition in the family.
The patterns which seem to be possessed by all or almost all species are the following: 
1. BT.
2. Lsh.
3. LD or Hdd.
4. Some form of Sct.
Several of the more specialized groups have developed much more elaborate repertories of display movements and postures. Almost certainly evolved independently.
This elaboration has proceeded along two lines:
1. Facial expressions --- Cebus, Ateles, Cacajao.
2. Movements of body and limbs, plus erection of hair tufts --- marmosets, especially Cebuells.

VI. Individuals of a few species (Cebus spp. and, possibly, Cacajao rubicundus) show a very marked tendency to learn to perform unusual and distinctive movements in certain abnormal conditions of captivity. Different individuals of the same species may learn very different patterns in similar circumstances. Such distinctive patterns may also function as signals, even when they are very different from any species-specific patterns. When individuals who have learned to perform such distinctive patterns are kept in a group with other individuals of their own species, the latter quickly learn to recognize the significance of the distinctive patterns, and respond appropriately. The