SEPTUM, HIPPOCAMPUS, PALLIAL COMMISSURES 447 



Fig. 35 Opossum, median sagittal section of the region of the cerebral ^com- 

 missures. Reconstructed from several sections, with addition of a fe\ir fiber 

 bundles which lie close to the median plane. 



Fig. 36. Opossum, transverse section at the rostral border of the anterior 

 pallial commissure to show the stria medialis Lancisii coming up from the pre- 

 commissural bundles and sending bundles to the fascia dentata and hippocampus. 

 Fig. 37 Opossum, from the same section as the left half of figure 29. It is 

 evident in this section that the alveus is continuous around the dorsal angle of 

 the ventricle with the corona radiata. The hippocampus stops at h and the 

 transitional region (subiculum) between hippocampus and general cortex is 

 bounded by the first radiating fibers. One would judge from this section that 

 the alveus carries fibers from the general cortex to the anterior pallial commis- 

 sure. Compare figures 39 and 40. The stria medialis Lancisii is a Wen""xiefined 

 bundle to which the membranous wall of the superior recess is attached. 



THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 23, NO. 5 



