INTERRELATIONSHIPS OF GENERA 



53 



species to species, in the number of closed triangles ; in some 

 species only the three posterior are closed, those in front being 



Fig. 25. — Neodon sikimensis Hodgson. 



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



shows the skull in dorsal view, natural size. 



more or less confluent with each other and with the anterior 

 loop, the tooth presenting an appearance which elsewhere is 

 characteristic of genera like Pitymys ; in other species four, five, 

 six, or even seven triangles may be closed, the tooth resembling 



