THE TEETH 



431 



FIG. 356. 



directed obliquely inward and forward. The first upper premolar 

 was absent. 



In one specimen in my collection the first premolar is absent and 

 the second upper premolar is double on both sides of the jaw (Fig. 

 356), presenting a very striking 

 example of the fusion of two 

 teeth, a variation which occurs 

 in human teeth, but until now 

 " rarely, if ever, recorded in 

 other animals." (Bateson.) The 

 left tooth (Fig. 357) is larger 

 than the right tooth. It presents 

 two serially arranged principal 



cusps separated by a vertical ABNORMAL SECOND UPPER PREMOLAR TEETH. 

 fissure. The anterior cusp has 



a small basal cusplet near the inner anterior end of the anterior 

 border ; the posterior cusp has a small posterior basal cusp and a talon. 

 On the inner side of the cingulum between the two principal cusps is 



FIG. 357. 



Posterior Cusp. 



Posterior Basal Cusp. 

 Cingulum. 



Posterior Fang. 



Anterior Cusp. 



Anterior Basal Cu*p. 



Anterior Fang. 



OUTER ASPECT. 



Anterior Cusp 



Anterior 

 Banal Cusp. 



Anterior Fang 



Middle Fang. 



Posterior Cus/>. 



Posterior Basal Cusp. 

 Cingulum. 



Posterior Fang. 



Miilille Fang. 



INNER ASPECT. 

 ABNORMAL LEFT SECOND UPPER PREMOLAR TOOTH. 



