110 R. S. Lull — New Tertiary Artio dactyls. 



Aletomeryx Antilocapra 



m. m. Ratio 



Length of centrum . . -0320 -0540 1-69 



Width, anterior face 0127 -0176 1-39 



Depth, anterior face . -0110 -0177 1-61 



Neural canal, height -0087 -0123 1-41 



Neural canal, width -0109 -0138 1-26 



Width across postzygapophysis -0220 -0360 1-63 



Ay. 1-50 



Cervical VII. — This bone again resembles very closely 

 that of the prongbuck, the main distinction being the 

 greater fore and aft extension of the zygapophyses, which 

 is true also of cervical VI (see fig. 11), and, although to 

 a less extent, of cervical V. In this feature there is indi- 

 vidual variation, at least one seventh cervical of Aleto- 

 meryx approximating that of Antilocapfa in this respect. 

 There are well developed capitular rib facets on the after 

 margin of the centrum, but the ventral spine is lacking in 

 both this and the preceding vertebra. 



The measurements of cervical VII are as follows : 



Aletomeryx 

 m. 



Centrum, length -0245* 



Centrum, width, posterior face .... '0190 



Centrum, height, posterior face. . . . -0130 



Neural canal, width -0123 



Neural canal, height -0090 



Width across postzygapophyses . . . -0254 



intilocapra 





m. 



Ratio 



•0377 



1-54 



•0327 



1-72 



•0186 



1-43 



•0164 



1-33 



•0140 



1-55 



•0390 



1-54 



Av. 1-52 



" Allowance made for lacking epiphysis. 



Dorsal vertebrae. — In the fossil the dorsal vertebrae are 

 ill preserved, as the spinous process is rarely present and 

 even the neural arch and transverse processes are gen- 

 erally imperfect. 



Dorsal I (fig. 12). — A nearly perfect example of this 

 element, aside from the one in the restoration, lacks only 

 the epiphyses and the tip of the spinous process. Again 

 the resemblance to the equivalent .bone in Antilocapra 

 is most striking, even to the paired longitudinal ridges 

 on the ventral aspect of the centrum. The chief distinc- 

 tion seems to be a double-ridged low process on the 

 posterior margin of the spinous process just above the 



