The term area TAa of Seltzer refers to the most external of three narrow, parallel cortical areas that line the upper bank of the superior temporal sulcus of the macaque. The others are area TPO of Seltzer and area PGa of Seltzer. Defined on the basis of cytomyeloarchitecture Area TAa is regarded as related to area TA of Bonin but distinct from the area on the surface of the superior temporal gyrus labeled TA, distinct from area Ts3 of Pandya and from area Tpt of Pandya. It differs from those areas by a predominance of supragranular layers, a prominent sublayer IIIc of the external pyramidal layer (III) and sublayer Va of the internal pyramidal layer (V) and a clear boundary between layer V and the multiform layer (VI). It differs from Ts3 in particular by lighter myelination in the bands of Baillarger and less dense vertical fibers ( Seltzer-1978 ).