83 



in length and half an inch in depth, slightly contracted in the midfJle. 

 This difference in the size of the supra-tympanic cell is obviously 

 not the eiFect of age, as the skuU of the Phasc. Vombatus compared 

 is that of an old animal with strong temporal ridges. In Phasc. la- 

 tifrons the articular surface for the condyle of the lower javv is 

 broader and less convex ; the anterior boundary of the zygomatic 

 space is less angular ; the palatai surface of the intermaxillaries is 

 deeper ; the curve of the lower border of the lower jaw is much 

 deeper ; the inner angle of the condyle is less produced ; the coronoid 

 process is higher and narro^ver, and the post-symphysial depression 

 is Edmost obsolete. 



The Secretary saw with much pleasure the decisive proofs which 

 Professor Owen had shown of the existence of two species of Woinbat ; 

 he had many years before been himself convinced of the fact, having 

 observed that they difFered in size and colour, and that one had a 

 sharp prick ear, -vvhile the ear of the other was low and elliptical. 



