65 



fourth premolars ; and in advance of this several small ones exist. In the 

 specimen represented in Fig. 11, Plate II, the mental foramen is situated 

 below the first premolar. 



Measurements from several specimens of lower jaws of Hyrachyus agrarius 

 are as follows : 



Length of space occupied by the molar teeth 



Distance from incisive alveoli to first premolar 



Length of hiatus between canine and first premolar 



Depth of jaw below last molar 



Depth of jaw below last premolar 



Breadth of jaw at canine alveoli 



Breadth of jaw below hiatus 



Length of symphysis 



Lines. Lines 



25 

 13 



14 



12 



28 



42 

 24 

 13 

 18 

 15 

 13 

 10i 



Lines. 



44 



20 

 1G 



Measurements of upper molar teeth are as follows : 



Inches. Lines. 



Length of the entire upper molar series 3 9 



Length of series of premolars 1 S£ 



Length of series of molars 2 1A 



Transverse. 



Diameter 

 Diameter 

 Diameter 

 Diameter 

 Diameter 

 Diameter 

 Diameter 



of first premolar . . . 

 of second premolar 

 of third premolar. . 

 of fourth premolar . 



of first molar 



of second molar . . . 

 of third molar 



Lines. 

 3 

 G 



7 

 H 



10 

 9A 



Comparative measurements of two upper last premolars are as follows : 



Liues. 



Fore and aft diameter in both 7 



Transverse diameter in one , S| 



In the other 9 



Measurements *of lower molar teeth are as follows : 



Lines. 



Liues. 



Lines. 



Length of the entire lower molar series. 



Length of series of premolars 



Length of series of molars 



20 



42 

 19 

 24 



44 

 20 



24J 



9g 



