DAKOTA AND NEBRASKA. 



309 



The symphysial extremity of the lower jaw is constructed as in the Horse, but the 

 intermediate portion is more cylindroid in its form. 



None of the fore teeth are preserved in the specimens, but the retained alveoli 

 indicate the same number of incisors and canines as in the Horse. 



The upper canines projected from the maxillaries quite near the suture of the pre- 

 maxillaries, and were separated from the incisors by a space little more than a line 

 wide. The lower canines were close to the incisors. 



The first small premolar, retained in the lower jaw of one of the specimens, is much 

 smaller than the corresponding upper tooth. It is inserted by a single fang, and has 

 a laterally compressed conoidal crown with a posterior heel. 



The length of the skull of Anchitherium Baircli from the summit of the inion to the 

 fore part of the upper jaw is seven and a quarter inches ; the length of the lower jaw 

 is six inches. 



Measurements derived from several of the best preserved specimens are as follow : 



Lines. Lines. 



Lines. Lines. Lines. 



Length from occipital condyles to front of upper jaw, 82 



Length from inion to fronto-nasal suture, . 



Length of sagittal crest from inion. 



Length of forehead. 



Breadth of do. at post-orbital processes. 



Breadth of do. at middle of orbits, . 



Breadth of cranium about middle, . 



Length of temporal fossa along middle, 



Height of do. at zygomatic root. 



Breadth of inion at par-occipitals, . 



Height of do., .... 



Breadth of face at middle of infra-orbital arches, 



Breadth at ant-orbital processes. 



Breadth at infrarorbital foramina, . 



Breadth at canine alveoli, . 



Length of nasals at middle. 



Breadth of do. at fronto-nasal suture, together. 



Breadth of do. at upper ends of premaxillaries. 



Height of orbit, .... 



Width of orbit, .... 



Length of lower jaw. 



Height of do. at condyle. 



Height of do. at coronoid process, . 



* Estimated. 



. 53* 



53 



53 







. 15J 



15 



17 







. 41* 



39 



39 



41 





. 32 







28 





. 28 







20 





. 24 



25 



22 







. 33 











. 18 





19 







. 21 





21 



21 







. 36 





38 







. 26 



26 



25* 



24 





. 18 



19 



18 



18 





. 10 









34 



. 19 



19 





17 



20 

 10 



. 15 







15J 





. 16i 



72 



29* 

 40* 



15 





