86 THE CEREBRUM. 



It is convenient to study the tentorial area of the basal surface 

 with the medial surface (Fig. 26). In this medial and tentorial 

 surface there are six important sulci and four fissures (Fig. 28). 



Of cingulum (s. cinguli) 



Callosal (s. corporis callosi) 



Subparietal (s. subparietalis) 



Occi pi to -parietal (s. occipito-parietalis) 



Inferior temporal (s. temporalis inferior) 



Ectorhinal (s. ectorhinalis). 



Calcarine (fissura calcarina) 



I Hippocampal (f. hippocampi) 

 Fissures < , . ., , ,, , . ., N 

 I Chonoidal (f. chonoidea) 



[ Collateral (f. collateralis). 



Sulcus Cinguli (Calloso-marginal Sulcus). Beginning under 

 the middle cut surface and extending in a curve forward, upward, 

 and backward, until it half encircles the corpus callosum; and, 

 then, turning upward to the supero-medial border and ending 

 just behind the central sulcus is the sulcus cinguli (Figs. 27 and 28). 

 It separates the gyrus cinguli and a marginal gyrus, including 

 the straight and superior frontal, from one another by its anterior 

 part; and, by its marginal end, separates the paracentral lobule 

 from the praecuneus. The sulcus cinguli is usually interrupted 

 by one annectant gyrus and often by two. These indicate its 

 development in three separate parts. 



At its beginning under the corpus callosum, the sulcus cinguli 

 is almost continuous with a small curved sulcus, which runs 

 nearly vertically downward, called the anterior parolfactory 

 sulcus (Figs. 28 and 29). Behind that little sulcus there is a 

 small curved gyrus, the parolfactory area (of Broca), which is 

 continuous with the gyrus cinguli and bounded behind by another 

 slight sulcus, called the posterior parolfactory sulcus. The 

 latter separates the area parolfactoria from the gyrus subcallosus. 



Subparietal Sulcus. About one inch above and behind the 

 posterior end of the corpus callosum there is an irregular sulcus, 

 called the Subparietal, which separates the gyrus cinguli of the 

 limbic lobe from the praecuneus of the parietal lobe (Fig. 28). 



The callosal sulcus is the deep furrow between the corpus 



