234 



MEMOIRS OF THE UNIVERSITY OP CALIFORNIA. 



and the metaconid is small; on the heel the entoconid approaches the size of 

 the hypoconid, and the hypoconulid is near the size of the entoconid. Dm 3 (fig. 

 14) possesses a large posterior cusp. A minute basal tubercle may be present 

 on the anterior side of this tooth. 



MEASUREMENTS OF MILK DENTITION 



No. 10831 



Dm 3 , greatest anteroposterior diameter 8.7 mm. 



Dm 4 , greatest anteroposterior diameter 15.5 



Dm 4 , greatest transverse diameter across heel 6.6 



Dm 3 , greatest anteroposterior diameter 14.6 



Dm 4 , greatest anteroposterior diameter 10.8 



Dm 4 , greatest transverse diameter 11.4 



VERTEBRAE 



Owing to the peculiar occurrence of remains at Ranch o La Brea it is very 

 difficult to obtain complete connected skeletons. The viscosity of the asphalt 

 mass in which the bones are entombed has permitted the elements of each 

 individual to move easily in many directions. It has therefore been found very 

 difficult to obtain connected parts such as occasionally appear in most deposits 

 of fossil remains. Particularly exceptional is it to find a vertebral column which 

 is even approximately complete, and in which all of the elements can be recog- 

 nized as belonging to one specimen and certainly distinct from numberless 

 other skeletons closely packed in the matrix. 



For the reasons just given it is difficult to make more certain of the vertebral 

 formula of Cams dirus than to learn that the relations of the vertebrae 

 where found in connected portions of the column, and as indicated by the 

 fitting together of the abundant material available, show no indication of a 

 variation in number of vertebrae from that of the modern timber wolves. 



Fig. 16. Canis dirus Leidy. Atlas, inferior view, no. 10834, X 

 Fig. 17. Canis dirus Leidy. Axis, lateral view, no. 10834, X ' 



Rancho La Brea Beds. 

 Rancho La Brea Beds. 



The atlas is rather variable in form, but resembles that of Canis lupus in 

 most respects. It differs from that of C. lupus mainly in the more common 

 tendency of the transverse processes to take on a triangular form. In C. lupus, 



