310 



The dentary ridge is near the median line of the oral surface, extending 

 about half its length, but nearer its posterior than anterior extremity. As 

 seen in Fig. 13, Plate XXXVII, it appears to be composed of the prominent 

 tubercular extremities of three connate columns, of which the back two 

 appear oval, and the anterior one rather clavate in outline. 



The measurements of the specimen are as follows : 



Lines. 



Length or depth of the anterior border 32 



Length or depth of the posterior border 11 



Thickness of the anterior column or border G 



Thickness at the second ridge of the inner surface G£ 



Thickness at the third ridge of the inner surface 8£ 



Thickness at the middle concavity of the inner surface , 7£ 



Thickness at the commencing ridge of the posterior slope of the inner surface. . . 10 



Fore and aft extent of triturating surface 36 



Length of dental tract 19 



