172 



DE. G ELLIOT SMITH ON THE BEAIN" 



elongated Sylvian fissure and the shallow intraparietal [lateral] sulcus undergoing a 

 process of disintegration into fragments indicate its Indrisine affinities beyond all 

 question. All of the other features of the brain accord with this interpretation. The 

 accompanying diagrams (fig. 58 and fig. 60), constructed from the data obtained from the 

 examination of the complete cranial cast (i and 3) and the two fragments (2), renders 

 further discussion of this brain unnecessary. 



The Form of the Brain in Palmopeopithecus maximus. 

 The bulk of this biain is slightly more than four times that of the cranial cavity of 

 the Lemur macaco the brain of which weighed 26 grammes ; so that v/e can roughly 

 estimate the size of this brain at 104 grammes. The largest recorded weights of 



Test-%. 61. 



S.frorU.u</:-.,C .1% 



S. /r-ont. OfdUr-; 



<./OS-- 



S- temp. sup. 



: 'intrapar. 



Diagram of tlie dorsal aspect of the brain of Palceoprojnthecus maximus. Natural size. 



recent Lemuroids, that of a Chiromys, 42*95 grammes (Max Weber), and my Lemur 

 varius, 39*0 grammes, are considerably less than half that of this large extinct genus. 



In form this brain diff"ers considerably from all other Prosimise except the existing 

 Chiromys and the extinct Megaladajiis: and in the case of these two the resemblance 

 is something more than one of mere shape, for a closer examination reveals many 

 points of identity in these three retrograde Lemuroids. 



