432 



MAMMALIAN ANATOMY 



a small cusplet. The crown is carried on three fangs, whereof the 

 middle and posterior are large and prismatic. 



The left sectorial is also abnormal (see p. 433). 



The right tooth (Fig. 358) is less complicated. The posterior 

 principal cusp is smaller, and the talon is wanting. The posterior 

 fang is united to the middle fang ; a groove on the outer aspect in- 

 dicates the line of attachment. 



FIG. 358. 



Posterior Cusp. 



Posterior Basal 

 Cusp. 



Posterior Fang. 



Anterior Cusp. 

 Anterior Basal Cusp; 



Anterior Fang. 



Posterior Cusp. 



Posterior Basal 

 Cusp. 



Groove. 



Posterior Fang. 



FIG. 359. 



INNER ASPECT. OUTER ASPECT. 



ABNORMAL RIGHT SECOND UPPER PREMOLAR TOOTH. 



Third Upper Premolar r- -\. Size. The variations in size 



appear to be confined to the tooth as a whole. I have no records of 



the presence of any additional fangs. 



Number. The upper sectorial is always present. Bateson describes 



and figures (Fig. 359) a specimen " having a large supernumerary 



tooth in each upper jaw. The 

 extra tooth was in each case a 

 small but accurate copy of the 

 carnassial tooth of its own side. 

 In each case the extra tooth 

 stood internally to the carnassial 

 tooth, extending from the level 

 of the middle of the carnassial 

 tooth to the level of the middle 



SUPERNUMERARY UPPER SECTORIAL TEETH. 



Form. I have observed two 



cases of malformation of the upper sectorial tooth. In the first speci- 

 men (Fig. 360) the anterior external cusp (protostyle) was absent, its 

 place being taken functionally by the overlapping talon of the pre- 



