336 



N. W. INGALLS 



iiig, its position will vary and may rise above or more usually 

 below the center of the lunate. " It will naturally be displaced 

 backward with the recession of the striate area and may be pres- 

 ent even though the lunate is wanting. Although variable it 

 can usually be recognized and is important since it lies between 

 two late differentiations of area 19, parieto-occipital and temporo- 



S. angulans 



post 



interparfetal 



sverse occipital 



lateral calcarine 



Fig. 19 Left hemisphere of Soudanese negress; same brain as figure 18. 



occipital areas. It may become confluent with the temporo- 

 parietal since they are both axial foldings in areas which lie one 

 behind the other. When this occurs and the temporo-parietal 

 unites with the superior temporal one has a not very infrequent 

 condition in which the long tortuous furrow extends from the 

 temporal almost to the occipital pole. In front of the anterior 

 and inferior occipital sulci, this long furrow separates the parietal 



