DAKOTA AND NEBRASKA. 



309 



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

 intermediate portion is more cyliudroid 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 AnchitJiermm Bairdi 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-uasal 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 infra-orbital 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* 



15i 



41* 



32 



23 



24 



33 



18 



21 



36 

 26 

 18 

 10 



19 



15 



16i 



53 

 15 

 39 



25 



26 

 19 



19 



53 

 17 

 39 



22 



19 

 21 

 21 



38 



25=' 



18 



41 

 28 

 20 



24 

 18 



17 



15 i 

 15 



34 

 20 

 10 



72 



29* 

 40* 



