138 



COMPARATIVE DENTAL ANATOMY 



grow continuously. They are tuberculate when 

 erupted, but soon wear into a characteristic pat- 

 tern. They have deciduous molars which are 



Fig. 48. — Skulls of Squirrels, showing excessive growth of incisors as 

 a result of injury. 



soon lost. The Squirrel family is very numerous. 

 They usually have the formula, — 



The incisors are medium in size, and are strongly 

 colored on the anterior face (Figs. 46 and 47). 



