THE MARSUPIALS, OR POUCHED ANIMALS. 99 



the peculiarities of the more embryonal or less 

 specialised type of the Phascolotherium as compared 

 with the Opossum of to-day. Upon the whole Owen 

 seems to us to be right, as regards the dentition, 

 in coming to the conclusion that from Phasco- 

 lotherium to Didelphys we have an advance from 

 the generalised to the specialised form. This sup- 

 position cannot, however, be extended to Plagiaulax. 



FIG. 2. 



A. Lower Jaw of Plagiaulax minor. Natural size. 



B. Lower Jaw of PI. medius. Tour times enlarged. 



This animal appears rather to be already so far 

 specialised that it advanced but little farther in 

 subsequent times ; nay, if the line were carried 

 down to the actual present, it might even be said 

 to have become effaced. 



The remains found of Plagiaulax show the 

 following connection with the living Marsupials. 



