392 



A MANUAL OF DENTAL ANATOMY. 



In addition to the great tusks the walrus ordinarily has a 

 row of four or five short simple teeth, worn down to the 

 level of the gums ; of these, the one placed immediately 

 within the base of the great canine is in the inter-maxillary 

 bone, and is an incisor : the ordinary dental formula is given 

 by Professor Flower as 



il dp*. 



1 l 3 



But there is some difficulty in assigning 'a definite dental 

 FIG. 173 



formula : for in front of the solitary incisor are often the 



(*) Side view of upper and lower jaws of a Walrus (Tricheclms rosmarus). 

 The upper jaw has been tilted a little to one side, in order to bring into 

 view the molar teeth at the same time with the long tusks. The deter- 

 mination of the teeth being open to question, they have been simply 

 umbered. 



