1862.] 



OF PITHECIA MONACHUS. 



329 



The whole of the cerebellum and the olfactory lobes are covered by the 

 cerebrum. The length of the cerebral hemispheres is 1*8 inch ; their 

 greatest breadth r5 inch; their height r2 inch. The upper surface 

 is arched, the parietal region being well developed. The occipital 

 lobes are full and broad, but not much elongated posteriorly, so that 

 they scarcely do more than cover the cerebellum in this direction. 

 The frontal lobe is depressed, and deeply excavated below ; the tem- 

 poral lobe vrell developed. In general form the cerebrum resembles 

 that of some of the Cebi ; it is less pointed in front than the brains of 

 most of the Old "World Apes, and less elongated and depressed than 

 in Nyctipithecus, CalUthrix, and Hapale. The olfactory lobes are 

 smaller than in most of the allied forms. There is nothing calling for 

 particular notice in the base of the brain (fig. 2), except that the 



Fig. 1. 



Fig. 2. 



corpora albicantia are not confluent, and the olivary bodies form 

 distinct projections on the medulla oblongata '2 inch long. The 

 cerebellum is large, the flocculi being particularly well developed. 



Fig. 3. 



The corpus callosum is •/ inch long; the portion of the cerebrum 

 anterior to it -4 ; that posterior to it '7 inch. 



The outer face of the cerebral hemisphere (fig. 3) is marked by a 



