﻿PLATE XT. 



[Enlarged about seven limes.] 



Sorex (Neosorex) navigator. Mouut Whitney, California. Showing changes in teeth 

 resulting from wear. 

 Figs. 1-3. Young adult (No. 42412). 

 4-6. Very old (No. 42413). 



1 and 4. Upper jaw (profile). 



2 and 5. Crowns of upper series of teeth. 



3 and 6. Lower jaw (profile) 



122 



