496 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



The neck of ^Theosodon was even longer proportionately 

 than in \Macrauchenia and the transference of the canal for 

 the vetebral artery from the transverse processes to the neural 



Fig. 245. — Development of the skull in the fMacrauchenidse, side views. A, \Theo- 

 sodon, Santa Cruz. B, ^Scalibrinitherium,Tsirana. (After Anieghino.) C, ]Macrau- 

 chenia, Pampean. (After Burmeister.) n., nasal bones. 



arch had already taken place, except in the first, sixth and 

 seventh vertebrae, and was thus less complete than in the 

 Pampean genus, in which all the vertebrae of the neck, save the 

 seventh, had the canal in its exceptional position. The odon- 



