R. S. Lull — New Tertiary Artiodactyls. Ill 



postzygapophyses. This is indicated but faintly in 

 Aletomeryx. There is a little distinction in the arrange- 

 ment of the minute foramina which penetrate the lateral 

 aspect of the centrum. In Aletomeryx the postzygapo- 

 physial facets are separate, in Antilocapra they are 

 confluent. 



The measurements follow: 



Aletomeryx Antilocapra 

 m. m. 



Centrum, length .- -019* -0290 



Height over all -055f -0900 



Width across transverse processes. . -038 -0567 



Neural canal, height, anterior end. . -011 -0134 



Neural canal, width -012 -0160 



* Allowance made for epiphyses lacking. 

 t Estimated. 



Dorsal XIII. — The thirteenth dorsal vertebra again 

 compares closely with that of Antilocapra, the principal 

 distinctions being the proportionately less height of the 

 centrum and the relatively lighter rib facets. The spin- 

 ous process is incomplete but it seems to have been less 

 erect in the portion preserved. 



The measurements follow: 



Aletomeryx Antilocapra 

 m. m. 



Centrum, length -0205 -0300 



Centrum, width, posterior -0200 -0280 



Centrum, height, posterior -0112 -0186 



Height over all -0430* -0700 



Width over transverse processes. . .0280 -0404 



Neural canal, height, anterior -0060 -0100 





Ratio 





1-53 





(1-63) 





1-49 





1-22 





1-33 



Av 



. 1-37 



Ratio 



1-46 



1-40 



1-66 



1-63 



1-44 



1-67 



1-44 



Av. 1.53 



Neural canal, width, anterior -0090 -0130 



* Estimated. 



Lumbar vertebrce. Lumbar III. — This bone differs 

 from that of Antilocapra mainly in the less pronounced 

 ventral ridge, the relatively greater fore and aft extent of 

 the summit of the spinous process, and the less pro- 

 portionate height of the centrum and of the entire bone. 



The dimensions are : 



