R. 8. Lull — New Tertiary Artio dactyls. 119 



Phalanges (fig. 17 A, B).— It has been extremely diffi- 

 cult to separate the phalanges of the fore feet from those 

 of the hind, the unguals only showing constant differ- 

 ences in a measure comparable to those of the prongbuck. 

 The unguals differ from those of the latter in having an 

 acuminate upper posterior angle, especially in those 

 referred to fore feet, whereas in the prongbuck this angle 

 is always rounded. 



Dimensions of the outer phalanges of the left manus 

 follow : 



Aletomeryx Antilocapra 



m. m. Eatio 



Proximal phalanx. 



Length -0278 -0500 179 



Shaft, width -0064 -0089 1-39 



Medial phalanx. 



Length -0167 -0278 1-66 



Shaft, width -0058 -0086 1-48 



Ungual phalanx. 



Length -0175 -0310 1-78 



Height -0120 -0217 1-80 



Width -0068 -0102 150 



Av. 1-63 



Lateral digits (fig. 17 B). — Of these there are preserved 

 the distal portion of a metacarpal, together with a proxi- 

 mal, two medial and two ungual phalanges, all from the 

 right side of a foot, but whether they represent the sec- 

 ond of the left or the fifth of the right manus I cannot 

 say. There is also the distal epiphysis of the metacarpal 

 and the proximal phalanx from the opposite side of the 

 foot. These seem to be a little larger and more robust 

 than do their opposites, but whether or not this is due to 

 individual variation can not be ascertained. The pha- 

 langes are typically flattened on their medial face, and 

 rounded externally. They bear much the same propor- 

 tions to one another as do those of digits III and IV. 



The dimensions are: 



l 2 



m. m. 



Length of proximal phalanx -0105 -01052 



Length of second phalanx -0040 -0040 



Length of ungual phalanx -0082 -0070 



