DAKOTA AND NEBRASKA. 



119 



Antero-posterior diameter of second upper true molar, 

 Transverse " " " 



Antero-posterior diameter of first upper true molar, 

 Transverse " " " 



Antero-posterior diameter of last upper premolar, . 

 Transverse " " " 



Antero-posterior diameter of tliird upper premolar, 

 Transverse " " " 



Antero-posterior diameter of second upper premolar. 

 Transverse " " " 



Antero-posterior diameter of first upper premolar, 

 Transverse " " " 



Antero.posterior diameter of superior canine, 

 Transverse " " " 



Antero-posterior diameter of last lower molar. 

 Transverse " " " 



Antero-posterior diameter of second lower molar, 

 Transverse " " " 



Antero-posterior diameter of first lower molar, 

 Transverse " " " 



Antero-posterior diameter of last lower premolar. 

 Transverse " " " 



Antero-posterior diameter of second lower premolar. 

 Transverse " " " 



Antero-posterior diameter of first lower premolar, . 

 Transverse " " " 



Antero-posterior diameter of lower canine, . 

 Transverse " " " . 



Li; C!5. 



Ci 



Gi 



6 



51 



4 



5 



4i 



4 



4 



3 J 



3 



2 

 3 

 3i 



lU 

 41 

 7 

 5 



5i 

 4i 

 5 



3i 

 3i 

 2i 

 3i 

 U 

 31 

 21 



Mertchtus medius. 



A second species of MerycTiyiis, to which the above name is given, is founded upon 

 a fragment of a lower jaw containing the true molars, and an isolated upper last 

 molar tooth. The specimens indicate an animal one-half larger in diameter than M. 

 elegnns, and intermediate in size to the Lama and Camel. 



The fragment of a lower jaw, with difierent views of the contained teeth, is repre- 

 sented in figures 12 — 14, plate XI. 



The first true molar has the crown nearly worn to its base. The last had not 



