Although the family name sometimes is spelled Callithricidae, the correct form is Callitrichidae.
Marmosets are among the smallest of primates.
Adults weigh from approximately 100 to 1,000 grams. The pelage is soft, dense, and, in some forms, silky. Often there are hair tufts and other adornments on the head. The face is naked or only sparsely haired. The coloration is quite variable in the family.