186 PHYSIOLOGICAL SERIES. 



To the mesial >ide of this suprasylvian sulcus there is a 

 " lateral" sulcus placed midway between the anterior and 

 posterior extremities of the hemisphere. It is widely separ- 

 ated from its morphological posterior extremity (fig. bl, E), 

 which is a notch on the caudo-mesial angle. The latter 

 may be regarded as the representative of the paramedian 

 sulcus of the Kangaroos. On the right hemisphere it is 

 joined to a long transverse " post-lateral " sulcus. The 

 small sulcus F (fig. 60) may represent the postsylvian 

 (posterior suprasylvian) sulcus of other Orders. 



There is a small separate prorean sulcus (fiir- (>1), and 

 behind it there is a short transverse sulcus G, which may 

 represent the coronal sulcus of other Orders. 



On the mesial surface (fig. 62) the typically Marsupial 

 arrangement of commissures and hippocampal formation is 



Fig. 62. (Nat. size.) 



RHIN . F. 



Been. The dorsal commissure is not elongated to ihe -nine 

 A tent as in the Kangaroos, so that it more closely re-emhle.* 

 that of the Polyprotodont Marsupials. The prolonged 

 genual sulcus is like that of the Kangaroo, a.- is al>o the 

 rostral sulcus. There is also the most extraordinary al 

 sence of the enlearine sulcus, ill place of which there 

 merely a .-mall irregular pit (ll). Lower down we Iii 

 -Imrt horizontal sulcus above the rhinal lis-ure (fi^. 



0. < . \:\-2:\ \ 



K. Owen, Todd's Cyclopedia, 1847, vol. iii. p. '2: 

 \\ . II. I- lower, Phil. Trans, vol. civ. 1865, p. 646. 



D. 223. Two easts of the cranial cavity of a Wombat (/'/ 

 omys ur&inufi). 



Tin admirably .-how the broad flattened cerchral 



