340 E. L. 'I'l'o.rdl — Early Pliocene One-Toed Horse. 



rather than Equus, but in the present specimen it may be a 

 character of youth. In the atlas the anterior notch is not 

 closed to form a foramen, in which respect it resembles the 

 more primitive forms. Likewise the intra- vertebral foramen in 

 the axis is not inclosed, showing that it is either primitive or 

 immature. 



Fore limb. — The bones of the limb are very slender. In 

 length the cannon bone nearly equals that of Equus scotti, but 



Fig. 5. 



Fig. 5. Atlas and Axis. Lateral, dorsal and anterior views. One-third 

 natural size. 



the width is scarcely more than half as great. The distance 

 from the hoof to the elbow, which constitutes about half the 

 height of a horse, in the new species is 23 inches ; therefore 

 the whole height is approximately 3 feet and 10 inches. Since 

 the scapula and humerus are not so long relatively, this dimen- 

 sion may be less. 



It is important to note that the distal segments, especially 

 the cannon bones, are long, suiting the animal to greater speed, 

 and here may be seen evidence that the race had changed its 



