Stereotaxic measurements of the calvarium of Macaca mulatta

¹ Department of Psychology, Walter Reed Army Institute of Research, Washington, D. C.

Stereotaxic measurements of the calvarium of the skulls of 40 rhesus monkeys were made, grouping data in five weight classes. Recording was made of distances in millimeters between the top of the calvarium and Horsley-Clarke, horizontal zero. This information permits the utilization of electrodes cut and attached to an anchoring pedestal prior to the time of surgery. Such a procedure considerably shortens the operation time thereby adding convenience and lessening risk. Information on the stereotaxic coordinates of principle skull landmarks as well as length and breadth of skulls from representative weight classes was evaluated.