PARTS OF A SKULL 307 



Parts of a Skull 



A skull is composed of a number of bones. The size and shape of these 

 bones vary more or less with different species, and they therefore form good 

 characters for distinguishing species and groups. The sutures indicating the 

 hues of junction between adjacent bones anchylose more or less in aged ani- 

 mals and become obscure. Below are the names of the principal parts of a 

 skull, with figures corresponding to those on the plate opposite. 



Skulls Nos. 1738 and 2087 are Southern California Skunks. Nos. 696, 

 2312 and 2332 are Columbia Gray Squirrels. 



