INTERRELATIONSHIPS OF GENERA 



83 



is essentially as in Microtus, the postero-median septum being 

 sharply defined and the postero-lateral pits deep and extensive. 



Fig. 52. — Ellobius fuscocapillus Blyth. 



Dorsal, ventral, and lateral views of skull, enlarged; the small figure 

 shows the skull in dorsal view, natural size. 



The pterygoid fossse are deep, their floors being slightly dorsal 

 to the ventral surface of the basisphenoid, and they are closed 

 anteriorly. The auditory bullse are very small and but slightly 



