IN THE EXTINCT LEMUES OE MADAG-ASOAE. 



165 



In proportion to its length this brain is considerably narrower and deeper than that 

 of any of the living species. This is probably a primitive featm-e, because the same 

 difference (in an even greater degree) is found in comparing the brains of the new- 

 born and adult of existing Lemurs. This observation is based upon the comparison of 

 six new-born Lemurs of the species catta, macaco, anAfuhus with adults. All of this 

 material was received from Captain S. S. Flower, Director of the Giza Zoological 

 Gardens. 



The narrowness of the hemispheres is most pronounced in the region in front of 

 the Sylvian fissure : in comparison with the posterior parts the frontal poles of the 

 hemispheres of Lemur jullyi are more slender and pointed than those of any living 



Test-fig. 53. 



fronts, orbit'. 



intj'a/jcw. 

 /hss. Syl^. 

 s. temp. sup. 



simts lateraZ: 

 cerebeZlitm^. 



Diagram of the dorsal aspect of the brain of Lemur jullyi. Natural size. 



Lemur. In this respect Lemur varius most resembles the extinct species ; although 

 the narrowness of the front portion of its hemispheres is not so pronounced as in the 

 species jullyi, it is distinctly slenderer than that of the other living species (compare i, 

 figs. 1, 2, and 3, page 326). 



Another noteworthy peculiarity of the brain of the extinct species is the very small 

 size of the orbital depression on the inferior aspect of the frontal region of the 

 hemisphere. In the different living species of Lemur the orbital area often extends 

 almost as far back as the fissure of Sylvius and, as a rule, both the orbital and fronto- 

 orbital [" diagonal " of my former memoirs, i, 2, and 3] sulci are placed within it 



z2 



