4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 01 



21. Width from outside to outside of outer incisors 77 78 



Length of premolar-molar series of teeth 170 179 



Length of premolar series 95 9$ 



Length of molar series 77 81 



Pm. 2 , height 60 75 



length 39 38 



width 26.5 27 



protocone 9-5 I0 



Pm. 3 , height 68 75 



length 30 30 



width 28 28 



protocone 12 13.5 



Pm. 4 , height 68 85 



length 28.5 29 



width 28.5 27 



protocone 15 r 4 



M.\ height — 80 



length 25.5 27 



width 27.5 28 



protocone 12 13 



M. a , height — 80 



length 26 27 



width 26 25 



protocone 12 14 



M. 3 , height — 75 



length 26.5 26 



width 24.5 23 



protocone 13 14 



Canine, length, fore and aft 12 — 



width 9 — 



1. 1 , greater diameter 18 19 



shorter diameter 10.5 13 



1. 2 , greater diameter 22 20 



shorter diameter 11 12 



1. 3 , greater diameter along worn surface 24 21 



shorter diameter 10 1 1 



It seems proper to make some remarks regarding certain of these 

 measurements. The orbit of the type of Equus niobrarensis appears 

 to be much larger than that of the Alaskan specimen ; but this is prob- 

 ably due to some distortion in the type. To the same is probably to 

 be attributed the apparent narrowness of the skull of the type at the 

 fronts of the orbits ; likewise, the narrowness of the palate ; while it 

 is probable that the width at the rear of the orbit is somewhat exag- 

 gerated. The relatively somewhat greater width at the glenoid 

 fossae is hardly due to distortion. 



The measurement numbered 2 is that called by Osborn (Mem. 

 Amer. Mus. Nat. Hist, n. s., Vol. 1, p. 85) the basilar length; that 



