368 



E. L. Troxell — Helaletes Redefined. 



As contrasted with Helaletes nanus, H. bo dps, the geno- 

 holotype, lacks distinctly separated cones on the inner 

 side of the premolars, while the two outer cones are 

 nearly eqnal in size and prominence. The first premolar 

 is very small. In this form the side of the maxillary 

 rises vertically above the premolars and ends in a sharp 

 edge to form the antorbital depression. 



This last feature is one of great interest and heralds 

 a peculiarity well known in fossil horses of later periods. 

 The presence of a facial depression, so far as I know, has 

 never been noted in an Eocene form; it was obscured 

 in the type of Helaletes, because the skull was so crushed 

 and so greatly distorted. 



Fig. 3. 



11807 



TYPE 



Y. P. M. 



Fig.- 3. — Helaletes hoops Marsh. Holotype. Skull restored from its 

 previous crushed condition. It now shows a rising sagittal crest, long 

 nasals, long diastemata in front of and behind the strong canine, the fora- 

 men over P 4 , and an opening in the face over the maxillary. It is distinctly 

 tapir oid. X 2 / 3 - 



Preparation of the Skull. — To develop this feature and 

 others as well, it seemed eminently worth while to risk 

 dismembering the rare skull to enable it to be restored to 

 a form approximately normal. This was done and the 

 result demonstrates these important points : the probable 

 slope from the occiput to the frontals, the great width 



