In terms of craniometry, we examined HERSHKOVITZ'S hypotheses that, in
Saguinus geoffroyi, populations on the western shore of the Rio Atrat
o were closely related to S. leucopus, and that a morphocline could be
traced from the eastern S. geoffroyi population to the western one. W
e detected a morphological sequence from east to west (or east to west
) but did not find any evidence supporting the former hypothesis.