686 



MR. F. E. BEDDARD ON THE 



[June 15, 



of which, however, the anterior is considerably the larger, corre- 

 spond to this. There is also here an asymmetry in the origin of 

 the arteries, the chief artery of the left side arising anteriorly to 

 the single posterior cerebral artery of the right side. The anterior 



Text-fig. 218. 



Cerebral arterial sj-stem of Myrmecopliaga jubata. 

 a.c. Anterior communicating artery. O. Optic nerves, v. Vertebral arteries. 



cerebellar arteries are also asymmetrical, thus conti-asting with the 

 arrangement met with in Tamandua. The right artery arises from 

 the circle of Willis ; the left arises just at the junction of the 



