32 



University of California Publications in Geology [Vol. 13 



dyle remaining on the right side indicates that it lacked the sharp 

 internal border which is so characteristic of Eumetopias and Zalophus, 

 though this condition may be due to the imperfect preservation and 

 to the wearing away of the edges of the fossil skull. 



Internally the outline of the foramen magnum is quadrangular, 

 with its sides converging strongly towards its superior border. In 

 dimensions the greatest transverse diameter of the foramen magnum 

 measures eighty-two millimeters, while its vertical diameter is seventy 

 millimeters. 



The outer incisor (Lj) is large (fig. lb) and somewhat caniniform, 

 with the longest diameter anteroposterior. Judging from the root 

 and alveolus, the internal incisor was considerably reduced in 



size and, compared with the external, about equal to one-half the 

 size of the latter, though still functional. In this connection it might 

 be pointed out that the outer incisors tend to be broken off or to 

 disappear in the adults of Eumetopias jubata while the inner ones 

 persist, and the latter are directed forward at approximately the same 

 angle as in Allodesmus. Without doubt the mandible belonged to an 

 old individual and this indicates that the inner incisor was retained 

 throughout life. It is situated slightly posterior to the outer incisor. 

 The alveoli indicate that the inner incisor was directed forward at an 

 angle of about forty-five degrees. 



Figs. 3, 4, 5. ?AUode$m,us Icernensis u. gen. and sp. Molar, Stanford Univ. 

 Coll., X 2. Temblor formation near Bakersfield, California. 



The canine (fig. la) is bluntly conical, directed slightly forward 

 and outward and curving slightly backward at tip, subovate at the 

 base in cross-section. Anterointernal portion considerably worn, due 

 no doubt to attrition by the upper incisors. The posterior portion 

 is slightly worn from being abraded by the upper canine but nowhere 

 near the amount exhibited by old individuals of Eumetopias. Further- 

 more, old adults of the latter do not have the anterointernal portion 

 of the canine worn to any appreciable extent. The root is very long, 

 extending backward to plane of third lower premolar. 



