162 



ON BEAINS OF THE POTTO AND SLOW LORIS. [Jan. 19, 



dividing into the two veiy stont posterior cerebi'als. The dis- 

 proportion between these arteries is very marked ; in the Potto 

 they are of about the same size. The postei'ior comnumicating 

 ai'tery is much thicker than the posterioi- cerebral fi'om which it 

 arises. It communicates, in the same way as in the Potto, with 

 the carotid considerably behind the point where the latter divides 

 into the middle and antei'ior cerebral arteries. Anteriorly there 

 is a stout antexior communicating artery, fi-om which aidses the, at 

 first, single anterioi- cerebral ; two fused anterior cerebi'als only 

 join for a brief space in the centre of the corpus callosum, separating 

 again almost immediately. 



Text-fig. 14. 



Base of brain of Lemur macaco. 

 c, carotid. Other letters as in text-fig. 13. 



Lemur coronatus resembles L. macaco ; for the two anteiior 

 cerebrals just befoi'e they disappear into the interhemisphei'al 

 fissure become fused, and after a short space of union separate 

 again. There is thus, as in L. Tnacaco, a more or less prolonged 

 union between the two anterior cerebi'als instead of a shoi-t bridge 



