WORM HEMISPHERE Lingula .... Vinculum lingulae Lobulus centralis Ala lobuli centralis Culmen Lobus quadrangularis Pars anterior Monticulus Declive t Pars posterior The lingula lies deeply placed in the incisura cerebelli anterior and consists of from four to six or eight small lamellae, which rest upon and are fused with the velum medullare anterius. Lateral from the posterior lamella., the vinicula lingulae extend toward the middle cerebral peduncle.
Behind the lingula, and separated from it by the sulcus praecentralis, follows the lobulus centralis, which overhangs the lingula and laterally sends out its the alae lobuli centralis.
The monticulus, the largest segment of the superior worm, lies behind the lobulus centralis, separated from the latter by the sulcus postcentralis. It includes the culmen and the declive and corresponds to the hemisphere-segment of the lobulus quadrangularis. The latter is subdivided by the sulcus superior anterior into a pars anterior and a pars posterior, corresponding to the culmen and declive respectively.
B. Lobus Posterior. The lobus posterior includes the hind part of the upper surface and the posterior half of the under surface of the cerebellum. It is separated from the lobus superior by the sulcus superior posterior, and from the lobus inferior by the sulcus postpyramidalis in the worm and by the sulcus inferior anterior in the hemi sphere. The sulcus inferior anterior may be readily identified if the course of the sulcus superior posterior be followed. It begins at the side, on the front border of the hemi sphere, in the sulcus horizontalis cerebelli at the place where the sulcus superior posterior opens, thence runs in a curve toward the worm, where it ends in the deeply pene trating sulcus posttyramidatis.
By means of the sulcus horizontalis and the sulcus inferior posterior, the posterior lobe of the hemisphere is subdivided into three parts, which correspond with two segments of the worm.