PARIETAL REGION IN THE PRIMATE BRAIN 



309 



row is found very far forward simulating a superior postcentral. 

 Indications of a superior parietal sulcus are sometimes met with. 

 The lunate sulcus is quite characteristic in that its mesial ex- 

 tremity has been pushed back by the large first annectant gyrus. 

 This end of the lunate often turns abruptly forward so that it 

 might be confounded wdth the paramesial which is at times in- 

 dicated, but the relations here are often difficult to interpret. 

 The occipital ramus usually turns slightly upward under the oper- 

 culum and is unbranched. Just above this last named sulcus, 



sulcus gyri angulans 



interparietal 



central caicarme 



inferior .occipital 



prelunate 



middle temporal 



Fig. 11 Posterior half of right hemisphere of Gorilla. 

 , specimen in the Royal College of Surgeons, London. 



Sylvian 



From a photograph of 



there may appear on the anterior wall of the lunate a short sagit- 

 tally placed furrow which may reach the surface and the signifi- 

 cance of which is doubtful. It might accommodate a slight 

 cortical increase which is cared for in other cases by the ''new 

 branch" of Cunningham which will be noted later. A deep short 

 prelunate, continued backward into the lower end of the lunate is 

 commonly found and is separated from the parallel sulcus by a 

 more or less deeply placed annectant gyrus. Certain other sulci 

 will be considered in what follows. 



