The term area Ts3 of Pandya refers to the most posterior of the three superior temporal isocortical areas defined on the basis of cytomyeloarchitecture in the macaque. Its internal structure reflects, in more pronounced form, trends that begin in area Ts1 of Pandya and develop through area Ts2 of Pandya to Ts3. These trends include an increase in the prominence of granule cells, increasing differentiation between the internal pyramidal layer (V) and the multiform layer (VI), a general increase in myelination, and emergence of the inner band of Baillarger. Area Ts3 also exhibits some features transitional to adjacent, more posterior and medial, areas of the auditory cortex ( Pandya-1973 ).