408 FIELD MUSEUM or NATURAL HISTORY ZOOLOGY, VOL. XI. 



Blarina brevicauda. 



Blarina brevicauda carolinensis. 



Blarina parva. 



Sorex longirostris. 



Sorex personalus. 



Sorex fumeus. 



Sorex richardsonii. 



Microsorex hoyi. 



Neosorex palustris. 



Upper Jaws and Teeth of Shrews, greatly enlarged. (After Merriam.) 



There is a surprising difference in the shape and size of both the skulls and the teeth in old and 

 young Shrews of the same species, and, when comparing skulls for the purpose of identification, the 

 student should select specimens of about the same age. 



