2QO LILY C. SHUDDEMAGEN. 



The most lateral projections of the cerebellum are two fairly 

 large sized bodies. These bodies, composed of a number of 

 folia and separated almost entirely from the remainder of the 

 cerebellum by a fissure, are the I obi floccuh. 



Each of these lobi flocculi consists of two distinct parts, the 

 flocculus (PI. XXIV., Figs. I and 2, Floe.} and the parafloccul.us 

 (PI. XXIV., Figs. 2 and 4, Par. Ft.}. The latter is much the 

 largest of the two, and almost completely hides the former from 

 view. From a dorsal view the paraflocculus (PI. XXIV., Fig. 4, 

 Par. Fl.} appears as a crescentic mass of folia, forming the lateral 

 projections of the cerebellum. 



Aside from the lobi flocculi, the remainder of the cerebellum 

 may be divided into three lobes, the lobus anticus (PI. XXIV., 

 Fig. 4, Lob. A.), the lobus centralis (PI. XXIV., Fig. 4, Lob. C.}, 

 and the lobus posticus (PI. XXIV., Fig. 4, Lob. P.}. 



The lobus anticus (PI. XXIV., Figs. 2, 3, and 4, Lob. A.) is 

 separated from the posterior part of the cerebellum by the fissura 

 prima (PI. XXIV., Figs. 2, 3, and 4, Fis. /). It is clearly visible 

 in a dorsal view of the brain (PI. XXIV., Fig. 4, Lob. A.), and is 

 not hidden between the lobus centralis and the cerebral hemi- 

 spheres, as is the case in the Chlamydophorus (Smith, 1899, Fig. 

 34) or in Xciutms (Smith). 



The lobus centralis (PI. XXIV., Figs. 2, 3 and 4, Lob. C.} is 

 separated from the lobus posticus by means of the fissura secunda 

 (PI. XXIV., Figs. 2, 3 and 4, Fis. 2}. It constitutes the largest 

 and most complex part of the cerebellum. It is a large irregular 

 area which has bulged forward and laterally, wedging its way 

 between the lobus anticus and the lobus flocculus. 



The lobus posticus (PI. XXIV., Figs. 2, 3 and 4, Lob. P.] is the 

 most caudal part of the cerebellum. It is small, consisting of but 

 few folia, and covers over almost completely the posterior part of 

 the fourth ventricle. 



(e} Myelencephalon. - - The embryonic division of myelen- 

 cephalon gives rise, in tne adult, to the medulla oblongata and 

 the pons Varolii. 



The medulla oblongata (PI. XXIV., Fig. 4, Mcd. Obi.} is the 

 most posterior part of the brain, and is continued directly into the 

 spinal cord. In the medulla oblongata is the fourth ventricle, 



