MORPHOLOGY OF THE BEAIX IX THE ^LnrMALTA. 



505 



essential features are represented diasframmatically in the accompanying sketches 

 (figs. 11 & li>). 



Fig. 41. — M'l/ahidiijiis tii(iJai/(i>:c(iriiii.sis. The dorsal aspect of ii (-Taiiial ca.^t. X ,-. 

 Fig. 42. — Mer/iiJadapis hiafhii/uscarunsis. Tile lateral aspect of the same. X ^. 



The form of the brain (especially the full rounded ])lunt anterior ends of the hemi- 

 spheres and the absence of a fronto-orbital edge) resembles that of C/urom//s. Tlio 

 arrangement of the furrows approximates most nearly to that seen in the Indrisiuae and 

 especially l/ulris. They are, however, fewer in number and simpler t'aan they are in 

 tlie latter. There can be little doubt as to the identity of the suprasylvian, lateral, 

 coronal, and postsylvian sulci, and the furrow / represents the similarly-labelled sulcus 

 in other Lemurs. The appai'ent absence of the orbital sulcus is notewoi'tliy. Burck- 

 hardt's extraordinary suggestion that the furrow which I have called " lateral " repre- 

 sents the precentril sulcus is peculiar, bec;iuse no central sulcus is present; but it is 

 preposterous to represent as the precentral a furrow which, according to his diagram 

 ioj). ciL p. 233, fig. 2 a), is placed parallel to and on a lower plane than the frontal 

 sulcus. 



But the most unwarrantable statements in Burckhardt's work are those accusing 

 Forsyth Major of mistaking the optic nerves for the olfactory bulbs. The latter 

 anatomist had carefully studied and described the skull of Ilegaladupis * long before 

 he attempted to describe the plaster mould of its cranial cavity. lie was therefoiH! 

 labouring under no misconception as to which lacunce in the cranial wall Avere the optic 

 foramina and which depressions were the olfactory fossee. So that when he came to 

 describe the cranial cast, there was no difficulty in recognizing as such the optic nerves 

 (even thovigh their position is so peculiar) and the olfactory peduncles (greatly elongated 

 though they are). In the account which Burckhardt criticises, the conformation of 

 the cranial region surrounding the disputed brain-area is carefully described (Proc. 



* •' On Miyaladii^iis inath'ij'tscai-uusif, an extinct gigantic Lemuroii.1," Pliil. Trans. li. vol. 1S.5, 1804, pp. 2.5 & ■2(i. 



